AN ABSTRACT OF THE THESIS OF
Kathy K. Verb le for the degree of Master of Science in Soil Science
presented on June 1, 1998. Title: Investigations of Soil Morphology,
Hydrology, Reduction-Oxidation Potentials, and Stratigraphy on a
Selected Hills lope in Western Oregon
Abstract approved:
Redacted for privacy
J. Herb
Huddleston
Hydric soils are defined through the hydric soil definition, and a
means to identify hydric soils has been established through hydric soil
criteria and Field Indicators of Hydric Soils in the U.S. However, the field
indicators are a recent development that requires more research and
testing to increase our knowledge of correlations between soil
morphology, hydrology, and soil processes and properties for all types of
landscapes and geomorphic processes.
The main objective of this study was to evaluate the Field
Indicators capability to identify those soils that met the hydric soil
definition on a selected hillslope. Further research and investigation
was done to determine whether the study area would meet federal
specifications for jurisdictional wetlands and assess stratigraphic units
and geomorphic processes that contributed to the present hydrological
conditions.
Morphological observations; soil physical, chemical, and
mineralogical analysis; collection and analysis of piezometric,
precipitation, soil temperature, and reduction-oxidation potential data;
vegetation characterization; and geomorphological and stratigraphical
investigation were used to characterize the soils and study transect
(Sites 1 through 4) on the backslope-footslope of Witham Hill in
Corvallis, Oregon.
Hydrologic, redox potential, and soil temperature data provided
documentation that the soils of Sites 2, 3, and 4 meet the conditions in
the hydric soil definition. Seasonal perched water tables ranging from
9.7-12.6 cm occur over a discontinuity consisting of slowly permeable
clays on the upper footslope; and temporary episaturation that gives
way to endosaturation with an average water table at 5.5 cm occurs on
the lower footslope. Redox data that indicated continuous iron
reduction for 21 to 30 weeks correlated with the morphological
properties for each of the three sites. However, morphological
characteristics of the soils on the upper footslope did not correspond
with the Field Indicators of Hydric Soils in the U.S., Version 3.2, 1996.
Two major factors that prevented positive outcomes for any
indicators were layer thickness requirements and the inability to round
a color that fell between color chips. A third factor was the requirement
that at least 60% of a designated layer have a depleted matrix. The first
two issues were addressed by the Field Indicator Committee of the
National Technical Committee for Hydric Soils in the Field Indicators of
Hydric Soils in the United States, Version 4 issued in March 1998.
Further investigation into study area characteristics found that:
(1) physical and mineralogical analysis supports the presence of four
stratigraphic units on the upper footslope; (2) mineralogy indicates that
the two clay units and the Spencer Formation that underlies the area
may share a common origin and that the clay units could be colluvial
material from the eroded Spencer Formation of once-higher surfaces;
and (3) soils at Sites 2, 3, and 4 meet the three criteria for identification
of jurisdictional wetlands.
C Copyright by Kathy K. Verb le
June 1, 1998
All Rights Reserved
Investigations of Soil Morphology, Hydrology, Reduction-Oxidation
Potentials, and Stratigraphy on a Selected Hills lope in Western Oregon
by
Kathy K. Verb le
A THESIS
submitted to
Oregon State University
in partial fulfillment of
the requirements for the
degree of
Master of Science
Presented June 1, 1998
Commencement June 1999
Master of Science thesis of Kathy K. Verb le presented on June 1, 1998
APPROVED:
Redacted for privacy
Major Professor, representing Soil Science
Redacted for privacy
Head or Chair of Department of Crop and Soil Science
Redacted for privacy
Dean of Gra
ate School
I understand that my thesis will become part of the permanent
collection of Oregon State University libraries. My signature below
authorizes release of my thesis to any reader upon request.
Redacted for privacy
Kathy K. Verble, Author
ACKNOWLEDGMENT
I wish to thank my advisor, Dr. Herb Huddleston, for the
opportunity, guidance, and patience he has provided over the past
several years. A thank you to committee members Dr. Jerry Kling, Dr.
Robert Frenkel, and Dr. Terry Gerros for their time and effort. I want to
express my appreciation to Will Austin who helped construct and install
equipment, provided assistance and encouragement, and was a source
of information and a sounding board for ideas; to Bob Frenkel for his
assistance in the vegetation characterization; to Reed Glasmann who
provided many hours of his time, his friendship, and guidance through
mineralogy; and to Joan Sandeno who volunteered her help in thesis
preparation.
A thank you to Janet Morlan and the Oregon Division of State
Lands for funding this study in the Wet Soil project in Oregon.
TABLE OF CONTENTS
Page
Chapter 1. Hydric Soils and Their Identification
1
Introduction
1
Background
1
Explanation of Problem
4
Objectives
5
Methodology
6
Chapter 2. Soil Morphology and Characterization of the Witham Hill
7
Backslope-Footslope Study Site
Introduction
7
Background
7
Description of Study Area
General
Climate
11
11
11
Methods
14
Results and Discussion
15
Morphological
15
Physical and Chemical
Mineralogical
Classification
20
29
36
Conclusion
Chapter 3. Hydrologic Regime and Reducing Environment at the
Witham Hill Backslope-Footslope Study Site
Introduction
36
39
39
TABLE OF CONTENTS (Continued)
Page
Background
General
Hydrology
Reducing Environment
Growing Season
Methods
General
Equipment Construction and Installation
Data Collection and Interpretation
Results and Discussion
Site 1
Site 2
Site 3
Site 4
Plots A-F
Summary of All Sites and Plots
Conclusion
Chapter 4. Field Indicators of Hydric Soils Application to the
Witham Hill Backslope-Footslope Study Site
39
39
40
42
48
48
48
49
52
55
56
58
71
79
89
100
102
105
Introduction
105
Background
106
Methods
108
Results and Discussion
108
Conclusion
113
TABLE OF CONTENTS (Continued)
Page
Chapter 5. Hydrophytic Vegetation and Wetlands at the Witham
Hill Backslope-Footslope Study Site
117
Introduction
117
Background
117
Wetland Hydrology Criterion
Hydric Soil Criterion
Hydrophytic Vegetation Criterion
118
121
121
Methods
126
Results and Discussion
127
Wetland Hydrology
Hydric Soils
Hydrophytic Vegetation
Conclusion
Chapter 6. Geomorphology and Stratigraphy of the Witham Hill
Backslope-Footslope Study Site
127
129
129
139
141
Introduction
141
Background
141
Geological Overview
144
Investigation
147
Results and Discussion
149
Observations
Mineralogical Analysis
Interpretation
149
152
159
TABLE OF CONTENTS (Continued)
Page
Geomorphology
Stratigraphy
Summary
159
164
173
Chapter 7. Summary and Conclusions
174
Literature Cited
180
Appendices
192
Appendix A NRCS Soil Characterization Data
Appendix B Soil Profile Descriptions
Appendix C Field Measurement Data
Appendix D Vegetation Characterization Data
Appendix E Mineralogy Laboratory Procedures
193
212
220
307
312
LIST OF FIGURES
Figure
Page
2.1
Location of study area in western Oregon
12
2.2
Cross-section diagram of site and plot locations on the
WSW-ENE transect
13
Random powder mount XRD patterns of weathered bedrock
samples from Pits 1, 2, and 3
30
Random powder mount XRD pattern of the 3Bsstyl clay
horizon
31
SEM micrographs of gypsum crystals and clay matrix from
the 3Bsstyl horizon
33
X-ray energy spectrometry of the crystals and matrix from
the 3Bsstyl horizon
34
Diagram of the instrumented sites and plots, excavated
pits and trench, and vegetation plots
50
Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Site 1
57
2.3
2.4
2.5
2.6
3.1.
3.2.
3.3.
Electrode potentials (top) at 10 cm, 30 cm, and 50 cm depths
and duration of saturation as measured by piezometers
(bottom) at Site 1
59
3.4.
Precipitation data (bottom) and water table data (top) below
the soil surface as observed a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Site 2
60
3.5. Water table data (top) below the soil surface with the errant
75 cm piezometer graphed separately at Site 2
62
LIST OF FIGURES (Continued)
Figure
Page
3.6.
Electrode potentials (top) at 10 cm, 30 cm, and 50 cm depths
and duration of saturation as measured by piezometers
(bottom) at Site 2
64
3.7.
Groundwater dissolved oxygen values (bottom) from
piezometric water and electrode potentials (top) at Site 2
66
Soil temperature data at 10 cm, 30 cm, and 50 cm depths
at Site 2
69
Soil temperature data (bottom) and electrode potentials
(top) at Site 2
70
3.8.
3.9.
3.10. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Site 3
72
3.11. Electrode potentials (top) at 50 cm, 30 cm, and 10 cm depths
and duration of saturation as measured by piezometers
(bottom) at Site 3
74
3.12. Groundwater dissolved oxygen values (bottom) from
piezometric water and electrode potentials (top) at Site 3
76
3.13. Soil temperature data at 10 cm, 30 cm, and 50 cm depths
at Site 3
78
3.14. Soil temperature data (bottom) and electrode potentials
(top) at Site 3
80
3.15. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 100 cm, 50 cm, and 25 cm depths at Site 4
81
3.16. Water table data (top) below the soil surface with the errant
84
75 cm piezometer graphed separately at Site 4
LIST OF FIGURES (Continued)
Figure
Page
3.17. Electrode potentials (top) at 25 cm, 50 cm, and 100 cm depths
and duration of saturation as measured by piezometers
(bottom) at Site 4
85
3.18. Groundwater dissolved oxygen values (bottom) from
piezometric water and electrode potentials (top) at Site 4
87
3.19. Soil temperature data at 25 cm, 50 cm, and 100 cm depths
at Site 4
88
3.20. Soil temperature data (bottom) and electrode potentials
(top) at Site 4
90
3.21. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Plot A
92
3.22. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Plot B
93
3.23. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Plot C
95
3.24. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Plot D .... 96
3.25. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Plot E
98
3.26. Precipitation data (bottom) and water table data (top) below
the soil surface as observed in a well at 100 cm and
piezometers at 75 cm, 35 cm, and 20 cm depths at Plot F
99
6.1.
Physiographic provinces of Oregon
145
LIST OF FIGURES (Continued)
Figure
6.2.
Page
Cross-section of the study trench showing the stratigraphy
from Site 1 to Site 3
150
XRD patterns of the 2Crt sample from Site 1
153
6.4. XRD patterns of the 2Bt1 gray clay horizon of Site 2
155
6.5.
156
6.3.
XRD patterns of the 3Bss olive clay horizon of Site 2
6.6. XRD patterns of the 4BCt horizon of Site 2
157
6.7. XRD patterns of the 2Bt gray clay horizon of Site 3
158
6.8. XRD patterns of the 3Bsstyl and 3 Bssty2 olive clay
horizons of Site 3
160
6.9. XRD patterns of the 4BCt horizon of Site 3
161
6.10. XRD patterns of the AB horizon of Site 2 and a Greenback
sample from the Bethel surface
163
6.11 XRD patterns of the <2 pm Mg-Glycol samples from horizons
at Site 3
167
6.12. XRD patterns of the 2Bt gray clay horizon of Site 3 and
a 2Bt Malpass horizon from a Dayton soil
169
6.13. Willamette Valley faults
171
LIST OF TABLES
Table
Page
2.1.
Morphological characteristics of the study area soils
16
2.2.
Morphological features of the study area soils
17
2.3.
Physical characteristics of the study area soils
21
2.4.
Chemical characteristics of the study area soils
22
3.1.
Periods of continuous saturation within the upper 30 cm,
seasonal mean water table levels, and periods of oxygen
and iron reduction for the four pedons of the study area
101
Periods of continuous saturation within the upper 30 cm
and seasonal mean water table levels for plots between
Sites 1-4
103
3.2.
4.1. Application of field indicators to the study area soils
5-1.
109
Wetland indicator category of plant species under natural
conditions
123
5.2.
Dominance determination for Site 1
131
5.3.
Dominance determination for Site 2
133
5.4.
Dominance determination for Site 3
135
5.5.
Dominance determination for Site 4
137
6.1.
Analysis of selected peak intensities for Site 2
165
6.2.
Analysis of selected peak intensities for Site 3
165
DEDICATION
This thesis is dedicated to Bobbie, a friend, whose journey on
earth has ended.
Investigations of Soil Morphology, Hydrology, Reduction-Oxidation
Potentials, and Stratigraphy on a Selected Hills lope in Western Oregon
Chapter 1
HYDRIC SOILS AND THEIR IDENTIFICATION
Introduction
"Wet soils" now known as hydric soils, wetland soils,
hydromorphic soils, aquic soils, waterlogged soils, meadow soils, and
many other names throughout the world (Dudal, 1992) were at one
time, and in some instances still are today, considered socioeconomic
nuisances. Wetness is a factor that may limit land use related to crop
production, construction, recreation, health and contamination by
affecting root growth, bearing strength and slope stability,
trafficability, microbial activity, and the movement of solutes.
In the last few decades, "wet soils" have become increasingly
important in issues of land development, land management, and
environmental preservation with the rising need for expansion and use
of marginal soils. "Wet soils", excluding Histosols, occupy
approximately 10% of the non-ice-covered landmass according to the
FAO-Unesco Soil Map of the World (Dudal, 1992). Intervention
through damming, drainage, irrigation, and construction has changed
the dynamics of free flowing water through landscapes, resulted in
degradation of water quality, led to subsidence of organic soils, and
destroyed or disrupted vital natural ecosystems.
Background
In the United States, a means to define and characterize "wet
soils" became necessary, in large part, because of the need by federal
and state agencies for the identification, inventory, management, and
regulation of wetlands. The necessity led to the recognition of a new
class of soils, hydric soils, and the means to identify them with the
development of the hydric soil definition, the hydric soil criteria, and the
Field Indicators of Hydric Soils in the U.S.
Federal regulation of wetlands for the maintenance of water
quality began to take effect on a broad scale in the 1970s (National
Research Council, 1995). The Federal Water Pollution Control Act
Amendments of 1972 extended the U.S. Army Corps of Engineers
(USACE) and the Environmental Protection Agency (EPA) regulative
authority to wetlands. The Clean Water Act 1977, Section 404, revised
the Corps' regulatory authority and heightened the need for
procedures to identifying and delineating wetlands (National Research
Council, 1995).
In the late 1970s, the Fish and Wildlife Service (FWS) requested
that a wet class of soils be developed to aid in identifying wetlands for
the National Wetlands Inventory of the USA (Mausbach, 1994). The
Soil Conservation Service (SCS) now called the National Resource
Conservation Service (NRCS), agreed to develop the wet soil
classification and a list of "wet soils." Work on the list began in 1977
under the leadership of W.B. Parker (National Research Council,
1995). The term "hydric soil" was coined by Cowardin et al. (1979) in
a FWS publication on the classification of wetlands and became the
accepted designation for a specific class of wet soils.
The main objective of the SCS was to define and create a class of
soils that normally would support hydrophytic vegetation and could be
identified with data from the Soil Resource Inventory (SRI) of the
National Cooperative Soil Survey. The agency considers "hydric soil"
as a "technical soil grouping" developed "for the application of national
legislation concerned with the environment and with agricultural
commodity production" (Soil Survey Division Staff, 1993). The hydric
soil definition was to set the standard for defining a hydric soil
(Mausbach, 1994) while the hydric soil criteria were designed primarily
for creating a list of hydric soils based on soil attributes documented
in Soil Taxonomy and listed in the Soil Interpretations Record (SIR)
database (National Research Council, 1995).
The first list of hydric soils was distributed to State SCS staff in
1980 for review and testing. In 1981, the SCS formed an ad hoc
committee called the National Technical Committee for Hydric Soils
(NTCHS) (National Research Council, 1995). The task of the NTCHS
was to review the comments, finalize the hydric soil definition, and
issue an approved list of hydric soils (Mausbach, 1994). The
committee was eventually expanded in 1985 to include representatives
from the U.S. Forest Service, the U.S. Fish and Wildlife Service (FWS),
the Bureau of Land Management (BLM), Corps of Engineers (USACE),
and the Environmental Protection Agency (EPA) (National Research
Council, 1995). The expansion provided a body of representatives
from agencies who must contend with hydric soils and jurisdictional
wetland issues. The hydric soil definition and the first edition of the
National List of Hydric Soils in the USA were published in 1985 (US
Department of Agriculture, Soil Conservation Service, 1985).
Over the past 20 years, the hydric soil definition and the hydric
soil criteria have evolved through testing and reviewing. The present
definition and criteria focus on saturation, duration of saturation,
growing season, anaerobic conditions (in the definition but not in the
criteria), and the upper part of the soil profile. The definition provides
a concept of a hydric soil but does not provide explicit factors for
identifying hydric soils in the field. The criteria, as mentioned, were
designed primarily for generating a list by searching existing NRCS
database. The inappropriate use of the criteria for on-site field
identification or verification of hydric soils was inevitable in the
absence of field procedures for identifying hydric soils. In response to
the misuse, the interagency NTCHS committee began in 1994 to
compile a list of indicators of distinct morphological features that are
observable in the field as a result of soil pedogenic processes in soils
that are saturated for long durations (National Research Council,
1995). A first draft version for review was issued in 1995 with input
from various regional, state and local agencies, universities, and the
private sector (US Department of Agriculture, Natural Resources
Conservation Service, 1996). Later that year, the NTCHS approved the
Field Indicators of Hydric Soils in the United States for identifying and
verifying the presence of hydric soils in the field.
Explanation of Problem
Identifying hydric soils under field conditions has become
increasingly important as hydric soils have become the "most common
and useful general indicator to support the substrate criterion for
wetlands" (National Research Council, 1995). Most hydric soils have
characteristic morphologies as a result of the biogeochemical
processes taking place during repeated periods of saturation or
inundation. The present field indicators are based on the soil
morphological properties, which are known to be associated with
saturation and reduction through past research and testing.
The hydric soil field indicators are under continuous scrutiny
and revision as our knowledge broadens on the long-term effects of soil
wetness. However, the characterization of wet soils by morphological
features related to biogeochemical processes has limitations (Dudal,
1992). Problems arise in identifying hydric soils when soil
morphological indicators are weak, nonexistent, difficult to interpret,
or when the soil morphology is inconsistent with the landscape,
5
vegetation, and hydrology (US Department of Agriculture, Natural
Resources Conservation Service, 1996). In addition, studies on hydric
soil morphology have focused largely on areas where the occurrence of
hydric soils is highest: areas with relatively flat topography, glacial or
coastal plain geomorphology, and high summer rainfall areas (National
Research Council, 1995).
Meaningful characterization of all hydric soils will require
continued research on the correlation between soil morphology and
hydrologic conditions for all types of landscapes and geomorphic
processes. The National Research Council (1995), in their report
reviewing the scientific basis for identification and delineation of
wetlands, recommended that more emphasis be placed on the
development of field indicators for hydric soils and more studies be
done on soils that are difficult to classify in the field. The increased
breadth of correlations will insure consistent identification and
compliance.
Objectives
In 1991, the Department of Crop and Soil Science at Oregon
State University initiated a wet soil monitoring program to investigate
the hydrology, morphology, and reducing conditions of various soils in
Oregon. The program was part of the Wet Soils Monitoring Project
initiated by the Soil Conservation Service. The national project is an
effort among wet soil researchers at Land Grant Universities in eight
states to investigate relationships among soil hydrology, oxidationreduction reactions, temperature, and morphology (US Army Corps of
Engineers, 1996). A hillslope wet soil monitoring project was
undertaken as part of Oregon State University's program in 1995 with
6
the goal to aid in the understanding of these relationships and in the
advancement of hydric soil identification.
The three main objectives of the hillslope wet monitoring project were:
(1) Determine if the soils along a selected backslope-footslope
transect are hydric according to the hydric soil definition
(Federal Register, July 13, 1994).
(2) Determine if the soils meet any of the current indicators in
the Field Indicators of Hydric Soils in the United States Ver.
3.2 (US Department of Agriculture, Natural Resources
Conservation Service, 1996).
(3) Evaluate the Field Indicators capability to identify those soils
that meet the hydric soil definition.
Additional objectives were to:
(1) Determine (if the soils are hydric) whether any part of the
study area could be considered a jurisdictional wetland.
(2) Assess the possible geomorphic processes that resulted in the
present hydrology and soil morphological characteristics.
Methodology
The objectives were accomplished through soil morphological
observations; soil physical, chemical, and mineralogical analysis; the
collection and analysis of hydrologic, climate, and biological activity
data, vegetation characterization; and geomorphological and
stratigraphical investigation. Methods for each area of research are
presented within the appropriate following chapters. Each chapter
reviews the literature for the accepted methods of research and
current concepts of hydric soil processes and properties.
7
Chapter 2
SOIL MORPHOLOGY AND CHARACTERIZATION OF THE WITHAM
HILL BACKSLOPE-FOOTSLOPE STUDY SITE
Introduction
The purpose of this chapter is to describe soil morphological
properties and selected physical, chemical, and mineralogical
properties. Soil morphology is obtained mainly by field identification
of soil attributes and variations that can provide a great deal of
information for interpretations and inferences about soil properties
and qualities. Soil characterization is accomplished mainly through
measurements of physical, chemical, and mineralogical properties by
laboratory procedures and provides quantitative data for determining
and interpreting soil properties.
Background
Historically, soil color has been one of the most used
morphological properties to describe and classify soils. Soil color can
serve as an indicator of the pedoenvironment and of past and present
soil processes. Soil color is due primarily to soil organic matter and
secondary iron oxides that form coatings on individual clay, silt, and
sand particles. Soil color interpretation is based on location within a
soil profile. In surface horizons, humic materials give the soil its dark
colors. Loss of organic substances from the surface horizons by
translocation is slowed by the complexation of mobile organic ligands
with iron (De Coninck, 1980).
In subsurface horizons, soil hue is a function of the type and
proportion of iron oxides present (Schwertmann and Taylor, 1989).
The type of iron oxide formed is influenced by the pedoenvironment
(moisture, pH, Eh, temperature, ionic environment, etc.)
(Schwertmann, 1993). Thus, the type of iron oxide formed is useful in
gaining information about a soil's pedogenic environment.
In general, iron gives aerobic soils their yellowish to reddish
hues with high chromas (Schwertmann and Taylor, 1989) and
anaerobic soils their grayish, greenish, and bluish colors with low
chromas (van Breemen, 1988b). Removal of iron by leaching or lateral
movement leaves soils with the light-gray colors of its matrix minerals.
Reviews by Schwertmann (1988), Schwertmann and Taylor
(1989), and Schwertmann (1993) provide data on iron oxide
identification, formation, and occurrence. Iron oxide identification can
be determined by the use of mineral-specific colors, dissolution
methods, and X-ray diffraction. Some forms of iron oxides, their
characteristic colors, and occurrences are discussed briefly.
Goethite (a- FeOOH) is the most stable phase of iron oxide under
soil conditions (Gotoh and Patrick Jr, 1974) and thus is the most
widespread Fe oxide in soils. Goethite is recognized by its hues
between 7.5YR and 2.5Y. Goethite can be formed from either Fe2+ or
Fe3+ cations in solution.
Ferrihydrite (5Fe203.9H20) is recognized by a hue of 5-7.5YR and
values <6. Ferrihydrite has poor crystallinity and forms in reducing
environments where reoxidation of Fe2+ cations occurs relatively
quickly or where constituents such as organic matter impede the
crystalline growth of other oxides.
Lepidocrocite (y- FeOOH) has hues of 5-7.5YR with values > 6 in
well-crystalline forms or 10YR in low concentrations. Lepidocrocite
requires Fe2+ ions for formation and therefore is indicative of soils with
reducing environments. Lepidocrocite occurs mostly as orange
concentrations in seasonally saturated soils and forms by slow
oxidation of Fe2+ ions.
9
Many physical, chemical, and biological properties and
processes affect soil morphology. An important physical property of a
soil is particle-size distribution. A soil's texture greatly affects ion
adsorption, rate of water movement, and translocation of solutes.
Textural variations within a soil profile affect the hydrologic properties
of a soil and can alter a soil's moisture regime. Not all textural
variations and contrasting textural changes (discontinuities) can be
identified or interpreted easily in the field. Lab particle-size
distribution analysis provides size distribution of individual particles
from colloidal clay (<0.2 jam) fraction to coarse fractions and can aid in
pedogenic and geologic interpretations (Soil Survey Laboratory Staff,
1995).
One biochemical process that affects iron distribution and thus
soil morphology is reductive dissolution. Reduction-oxidation (redox)
reactions result in the solubilization (reduction) of iron and manganese
oxides by bacterial respiration in anaerobic conditions. The mobile
reduced ions may be transported by water movement out of the soil
profile and/or horizon or may diffuse to areas of higher 02 partial
pressures and accumulate as Fe and Mn oxides (Schwertmann, 1993;
van Breemen, 1988b). Processes and effects of reductive dissolution of
iron and manganese oxides have been reviewed by many authors:
Ponnamperuma et al. (1967,1968); van Breemen (1987, 1988a,
1988b); Turner and Patrick Jr (1968); Ponnamperuma (1972);
Gambrell and Patrick Jr (1978).
Reductive processes which occur through microbial reduction
and complexation by organic ligands (Schwertmann, 1988) are affected
by the organic matter content of a soil (Dobos et al., 1990). Microbial
reduction requires an energy source that is supplied by soil organic
carbon. Low quantities of organic matter limit microbial reduction and
formation of Fe and Mn organic complexes. Rowell (1981) reported
10
that organic matter content less than 1.5% greatly affects the soil's
capacity for reduction and that organic matter content greater than
3% can lead to highly reduced conditions.
One component of a soil that can affect both iron translocation
and pH is aluminum. Soil pH is important because it plays a major
role in reduction-oxidation reactions, activity of microorganisms,
solubility of various compounds, complexation reactions, and
adsorption of ions to exchange sites (McLean, 1982). Aluminum can
serve as a proton donor during iron reduction resulting in
exchangeable Fe2+ if the exchange complex has A13÷. "Forced" ion
exchange occurs when Al3+ is hydrolyzed to Al-hydroxide or Al-hydroxy
species of lower charge and Fe2+ replaces the hydrolyzed aluminum
(van Breemen, 1988a).
Color variations in mineral soils as a result of redox processes
involving Fe and Mn compounds in continuous or recurrent reducing
conditions are called "redoximorphic features." The features are visual
evidence of reduction, translocation, and oxidation of free oxides
resulting from the water table regime. Many studies (Boersma et al.,
1972; Veneman et al., 1976; Vepraskas and Wilding, 1983;
Frammeier, et al., 1983; Evans and Franzmeier, 1986; and Cogger
and Kennedy, 1992) have correlated the occurrence of redox features
with water table behavior. Thus, soil color and color patterns
commonly are used in the field to indicate soil moisture regimes (Soil
Survey Division Staff, 1993), infer soil-drainage classes, and to identify
hydric soils (US Department of Agriculture, Natural Resources
Conservation Service, 1996).
Vepraskas (1994) describes the three major categories of redox
features: (1) redox concentrations, (2) redox depletions, and (3)
reduced matrices. Redox concentrations include: masses (soft bodies);
nodules and concretions (firm irregularly shaped bodies); and pore
11
linings (coatings on a pore surface or impregnation of the matrix
adjacent to a pore). Redox depletions are bodies with low chroma (.2)
and values of 4 or more where Fe-Mn oxides or Fe-Mn oxides and clay
have been stripped out. Reduced matrices have Fe2+ that gives the soil
low chroma color (.2) in situ but oxidizes to Fe3+ when exposed to air.
Description of Study Area
General
The study area is on a backslope-footslope transition on Witham
Hill at the OSU poultry farm. Witham Hill is northwest of Corvallis
and lies on the western margin of the southern Willamette Valley in
Benton County, Oregon (Fig. 2.1). The low hill ranges in absolute
elevation from 85.3 m to 146.2 m (280-480 ft). The WSW-ENE
transect ranging from 86.2 m to 103.4 m (283-340 ft) in elevation was
selected to include a dry upland soil and a wet drainageway soil. The
hillslope shape (Ruhe, 1975) changes from a convex-linear shoulder to
a concave-linear footslope just below Site 1 (at the top of the transect)
and then changes to linear-linear level at Plot F (near the lower end of
the transect) (Fig. 2.2). The slope gradient ranges from 23% at Plot A
to 2% at Site 4. According to the Soil Survey Staff (1975a), the soils of
the upper and mid transect positions are underlain by sedimentary
bedrock and the soils of the lower portion of the transect were
developed in recent (Holocene) alluvium.
Climate
The climate is characterized by a moderate marine climate of
cool, wet winters and warm, dry summers giving the soils a xeric
moisture regime and a mesic temperature regime. The average annual
precipitation in the low elevations of the study area ranges from 101.6
12
Figure 2.1. Location of study area in western Oregon. (a) Corvallis in
southern Willamette Valley (from McDowell, 1991). (b)
Topo of Witham Hill 44°34'14" N and 123°18'00" W.
IRK:HEEL
(a)
BASIN
';;;11
V.777:
'!!!!
0
Albany
SOUTHER
.. .
WILLAMETTE"
........
VALLEY
..
.
.
619
(b)
MARRSON
:."/
.1.Actrs6iv
....
....... .......
.......
V-2-1 -
\\
.....
Dui
Figure 2.2. Cross-section diagram of site and plot locations on the
WSW-ENE transect.
1
BC2
E
3
Sites (1-4) and Plots (A-F)
F
4
14
cm to 114.3 cm (40 to 45 inches), 50 percent of which falls from
December through February (Taylor and Bartlett, 1993). Mean high
and low temperature ranges between 32° and 18° (C) in summer and
between 4.5° and 0° (C) in the winter. The average monthly mean
temperature is 4.20C in January and 18.80C in July (Taylor and
Bartlett, 1993).
Methods
Four backhoe pits were excavated to a depth of 1.5 m (5 ft) along
one transect. Soil profiles were described using standard terminology
as given in the Soil Survey Manual (Soil Survey Division Staff, 1993).
Soil color determinations were made using Munsell Soil Color Charts.
Particular attention was given to soil color and redoximorphic features.
Color was not rounded to the nearest chip as practiced by Natural
Resource Conservation Service (Soil Survey Division Staff, 1993).
Color notations were made with plus (+) or minus (-) when appropriate.
A (+) or (-) next to a value and/or chroma indicates which chip was the
closest match when the sample color was between color chips.
Redoximorphic features were identified and described by type
according to Vepraskas (1994). Abundance, size and distinctness of
redox features were noted according to the Soil Survey Manual (Soil
Survey Division Staff, 1993). It was assumed that reddish masses and
concentrations were mainly composed of iron and that black masses
and concentrations were composed mainly of manganese.
Soil profiles were sampled with the aid of Warren Lynn, a
Natural Resource Conservation Service (NRCS) soil scientist, following
standard procedures (Soil Survey Laboratory Staff, 1996). The NRCS
National Soil Survey Laboratory (NSSL), Lincoln, Nebraska performed
characterization analysis. Soil characterization data sheets from the
15
NSSL on physical, chemical, and mineralogical properties are in
Appendix A.
Additional mineralogical analyses were performed on samples
from selected horizons. X-ray diffraction (XRD) analyses were run on
random powder mounts (Moore and Reynolds, Jr., 1989) of bulk
samples from a clay horizon from Pit 3 and the soft bedrock from Pits
1, 2, and 3 to identify the major mineralogy. Analyses were made with
a Phillips XRG 3100 Automated XRD unit using monochromatic Cu Ka
radiation at 40kV and 35mA. The random power mounts were run in
the 6-650 20 increment. In addition, the Site 3 clay sample also was
analyzed with scanning electron microscopy (SEM). The sample was
mounted on an Al stud with Duco cement and sputter coated with AuPd. The sample was examined with an AMR 1000 scanning electron
microscope equipped with a Kevex energy dispersive X-ray analyzer.
Results and Discussion
Morphological
Selected morphological properties are presented in Tables 2.1
and 2.2. Detailed profile descriptions of morphological observations
are in Appendix B. Textural classes in the profile descriptions were
determined from field texture.
There were some contrasting morphologies between the soil
profiles of the four pedons at the study site. Obvious differences
between the soils were solum depths, soil colors, occurrence of clay
horizons, location and abundance of redoximorphic features, and
accumulations of white crystals (Table 2.1 and 2.2).
Pit 1, located on the backslope, had the shallowest solum with
fractured bedrock starting at 95 cm below the soil surface. A cambic
B horizon has developed over slightly weathered sandstone. The
16
Table 2.1. Morphological characteristics of the study area soils.
Depth
Horizon
Hue
(cm)
Matrix Color
Moist
Texture
Dry
Structure
Boundary
grade-size-shape
Site #1
0 -7
7-19
19-46
46-65
65-95
95-130
130-155
Al
0 -7
7-14
14-27
27-36
36-50
50-70
70-92
92-109
109-142
142-155
155-170
Al
0 -7
7-16
16-27
27-42
42-91
91-120
120-135
135-153
153-175
Al
A2
A3
BA
10YR
10YR
10YR
10YR
10YR
Bwl
Bw2/2Crt 10YR
2Crt
2.5Y-10YR
3/3
3/3
3/3
4/3
5/4
4/4
6/3-4/6
5/3
5/3
5/3
6/3
6/4
6/4
7/3-4/6
cl
cl
cl
cl
cl
5/3
5/3
5+/2
5+/2
sil
sil
sicl
sic
2FSBK
2FSBK
2MSBK
1MPR/2MSBK
2MPR
1CSBK
cs
gs
gs
gs
2VFSBK
2VFSBK
2MSBK
1CSBK
1MPR/2MSBK
cs
as
2MPR/2CSBK
aw
OMA
OMA
OMA
gw
cs
cs
cs
gi
gw
Site #2
A2
A3
AB
B/E
E/B
2Bt1
3Bt2
3Bss
4BCt1
4BCt2
10YR
10YR
10YR
10YR
10YR-10YR-7.5YR
10YR-10YR-7.5YR
2.5Y
2.5Y
2.5Y
2.5Y-7.5YR-7.5YR
2.5Y-2.5Y-10YR
3/2+
3/2+
3+/2
4/2
5/2-4/4-4/6
5/2-5/6-4/6
5/2
5/3+
4/4
6/3-5/6-4/6
6/3-6/4-6/8
6/2-6/4-5/6
7/2-6/6-5/6
6/2
cl
el
cl
sicl
sic
gs
gs
cs
6/3+
c
6/4
7/3-6/6-5/6
7/3-7/4-7/8
c
cl
cl
5/2+
sil
sil
2MGR
6/2+-5/6-5/6
7/2-6/6-6/6
6/2
6/2-6/3
6/4-6/3
6/4
7/3-6/8
cl
2MSBK
2CSBK
aw
OMA
OMA
OMA
gs
gs
gs
1CSBK
gs
4/1
4/1
4/1
3/1
3/1
3/1
3/1
sic
sic
2MGR
2FSBK
2FSBK
2FSBK
2CPR
2MPR
cs
cs
cs
gs
gs
ab
Site #3
A2
B/E
E/B
2Bt
3Bss
3Bsstyl
3Bssty2
4BCt
10YR
10YR
3/2+
10YR-10YR-7.5YR
10YR-10YR-7.5YR
2.5Y
2.5Y
2.5Y
2.5Y
2.5Y-10YR
4/2
4/2+-4/6-4/6
5/2-5/6-5/6
4/2
4/2-5/3
5/4-5/3
5/4
6/3-5/8
10YR
10YR
10YR
10YR
10YR
10YR
10YR
3/1
3/1
3/1
2/1
2/1
2/1
2/1
5+12
sicl
c
c
c
c
1CSBK/2FSBK
sicl
Site #4
0 -6
6-18
18-35
35-51
51-90
90-133
133-163
Al
A2
AB
BA
Bt
Bssl
Bss2
c
c
c
c
c
OMA
cw
cs
cw
Table 2.2. Morphological features of the study area soils.
Depth
cm
Horizon
Surface and Matrix Features *"
Additional
Color
moist
Features
Fe masses/depletions
amount size rom
Additional Additional Additional
Features Features Features
Site
0 -7
7-19
19-46
46-65
65-95
95-130
130-155
Al
0 -7
7-14
14-27
27-36
36-50
50-70
70-92
92-109
109-142
142-155
155-170
Al
0 -7
7-16
Al
A2
FeM-mfd & OR-cd
16-27
B/E
E/B
OR-fd
FeM-cfd
FeM-mfp
FeM-cff
FeM-cff
A2
A3
BA
Bwl
Bw2/2Crt
2Crt
DP-fff
FeM-fff
FeC-ff
FeC-ff
FeC-ff
10YR 5/6
FeCC & CCO
CF-cd
Site 2
A2
A3
AB
FeM-mfd/cmd
FeM-cfp/fmp
5YR 4/6 & 7.5YR 4/6
10YR 4/6 & 7.5YR 3/4
10YR 4/6 & 7.5YR 4/6
FeM-mfd
FeM-cff
FeM-cff & DP-cmd
7.5YR 5/6 & 7.5YR 5/8
10YR 5/8
10YR 5/8 & 5Y 5/2
FeM-mff
B/E
E/B
2Bt 1
3Bt2
3Bss
4BCt1
4BCt2
MnN-ff
MnN-ff
MnN-ff
MnN-ff
FeN-ff & MnC-ff
FeN-ff & MnC-if
MnS-vfp
SLS-vfd
SLS-fd
SLS-cp
CF-fd
CF-fd
CF-fd
CF-vfp
CF-vfp
GY-ffp
Site 3
27-42
42-91
91-120
120-135
135-153
153-175
0- 6
6-18
18-35
35-51
2Bt
3Bss
3Bsstyl
5YR 4/6 & 7.5YR 4/6
7.5YR 5/8
7.5YR 4/6
10YR 5/8
10YR 5/6
10YR 5/6
3Bssty2
MnFeC-ff
MnFeC-ff
MnS-cp
MnFeC-ff
FeC-ff
SLS-fd
FeC-ff & MnM-ffd
SLS-md
MnN-cf & MnM-ffp SLS-md
MnS-fp & MnN-ff
SLS-md
4BCt
Al
A2
AB
BA
CF-fd
CF-ff
CF-vff
GY-fmd/fmp
CF-fp/fd
GY-ffp
CF-fd
OR-md
FeM-mfd/mff/cfd
FeM-mfd/cff/mmd
FeM-mfd/cff
Site 4
7.5 YR 4/6
7.5YR 4/6-3/4 & 5YR4/6
7.5YR 5/8 & 5YR 3/4-4/6
MnS-vff
FeC-fff & MnS-fd
OR-md
OR-fd
MnN-cf
7.5YR 4/6-5/6
Bt
51-90
MnN-ff/fm
SLS-vfd
FeM-fff
90-133 Bssl
10YR 3/4
SLS-cd
FeM-fff
10YR 3/4
133-163 Bss2
SLS-md
* Abbreviations taken from Soil Survey Staff (1993) unless otherwise noted
** M = masses, DP - depletions, C - concretions, N - nodules, S = stains, CO - coatings, CF = clay films
SLS = slickensides, GY = gypsum, OR = oxidized rhizospheres
CF
18
bedrock is composed of sandstone with some areas of interbedded
siltstone. Matrix hue of the soils was 10YR while the dominant matrix
hue of the underlying sandstone was 2.5Y. Color values and chromas
were > 3. The only redoximorphic features were small (<0.5 mm) Fe
concretions between 7 cm and 65 cm beneath the soil surface and a
few fine Fe masses between 65 cm and 95 cm. Soils dominated by
high chromas and few iron redox features are associated with very
short periods of saturation (Veneman, et al., 1976). The fact that no
redox features other than small concretions occur within the upper 65
cm indicates quick changes between reductive and oxidative
conditions (Blume, 1988).
Soils in Pits 2 and 3 had very similar morphology and were
different in many ways from soil in Pit 1. Pit 2 (17.4 m downslope
from Pit 1) and Pit 3 (30.9 m downslope from Pit 2) had sola that were
170 cm deep to highly weathered sandstone. In addition, Pits 2 and 3
had a clay substratum that was lacking in Pit 1. A contrasting texture
change and an abrupt boundary (Table 2.1) suggest a discontinuity
between the 1OYR subsurface horizons and the 2.5Y clay substratum.
The soils in Pits 2 and 3 showed a trend toward higher values
and lower chromas in the horizons compared to soils in Pit 1.
Macromorphic redox features in Pit 2 started at 7 cm below the soil
surface with many faint iron masses. Distinct iron masses and
manganese nodules were present at 14 cm below the soil surface.
Macromorphic features in Pit 3 included a dominant matrix value and
chroma of 4/2 at 7 cm below the soil surface. Common distinct
oxidized rhizospheres, many distinct iron masses, and few Mn.-Fe
concretions were also present at this depth.
The B/E and E/B horizons over the clay substratum and
redoximorphic concentrations close to the soil surface of Pits 2 and 3
suggest that water is perching over the slowly permeable clays.
19
Impeding layers can cause a restriction in water distribution and lead
to perched water tables and more rapid saturation conditions (Knapp,
1978). Franzmeier et al. (1983) found that gray (chroma ..2) horizons
were zones through which water fluctuated the most and duration of
saturation was the longest. Simonson and Boersma (1972) found that
faint and distinct concentrations increased with an increase in water
saturation, and Blume (1988) concluded that slow changes between
reductive and oxidative conditions favored the formation of iron and
manganese masses over concretions.
Interesting was the difference in the thickness of the solum
above the clay horizons for Pits 2 and 3. Although the land slope is
between 5-6% for both sites, the solum above the clay at Site 2 was 70
cm thick and 42 cm thick at Site 3. The transitional B/E and E/B
horizons occur between 36 and 70 cm in Pit 2 and between 16 and 42
cm in Pit 3. Field interpretations suggest that the Pit 3 depleted
horizons are closer to the surface due to the shallower solum above
the clay horizons.
Slickensides, which are common in swelling clays that are
subject to changes in water state (Soil Survey Division Staff, 1993),
were observed in the clay horizons of Pits 2 and 3. The slickensides
were fairly large with the largest approximately four to five inches deep
and up to a foot across. Also noted in the lower horizons of the clay
substratum were clear and white fibrous crystal accumulations that
looked like gypsum. Pit 2 had few, prominent white crystals in the
413Ct1 horizon. The 3Bssty 1 horizon of Pit 3 had distinct and
prominent clear and white crystal clusters. The underlying 3Bssty2
horizon had a few prominent white crystals.
The Pit 4 soils, located on the lower footslope, had different
morphology from the other three pits. The silty clay surface horizons
and clay subsoil and substratum had very dark colors (s3 values and
20
1 chromas). Macromorphic redox features started at the soil surface
with many distinct oxidized rhizospheres. Oxidized rhizospheres are
"iron coatings" on plant roots. Leakage of oxygen from plant roots, in
species that can transport oxygen to their roots in saturated soils,
oxidize nearby ferrous (reduced) iron compounds (Vepraskas, 1994).
Many and common, faint and distinct iron masses began at 6 cm
below the soil surface. Slickensides were noted starting at 51 cm
below the soil surface.
Mineral-specific colors of iron oxides were used for field
identification of the types of oxides present. The dominant hue colors
(10YR and 2.5Y) of the soils in all the pits indicate that a large portion
of the iron that coats the matrix materials is probably goethite. The
majority of the redo)dmorphic iron concentrations appear to be
ferrihydrite (hue of 5-7.5YR and values <6). There may be some
lepidocrocite in the matrix and redox concentrations (hues of 5 -7.5YR
with values <6 in forms that have poor crystallinity). The redox
concentrations are believed to lack any hematite (hues of 5YR or
redder) since hematite does not occur in soils with ferrihydrite
(Schwertmann and Taylor, 1989).
The natural drainage classes for the soils, based on
redoximorphic features, are moderately well drained on the backslope
(Site 1), somewhat poorly drained on the upper footslope (Sites 2 and
3), and poorly drained soils on the lower footslope (Site 4).
Physical and Chemical
Selected physical and chemical characterization data for the four
pedons studied are listed in Tables 2.3 and 2.4. Some soil properties
varied markedly between soil pedons and within soil profiles.
21
Table 2.3. Physical characteristics of the study area soils.
Depth
Horizon
Particle-size distribution*
Texture Clay % Silt % Sand % Fine clay %
Fine clay/
Total clay
Clay-free COLE**
LEP^/clay
Sand %
(cm)
Site #1
0 -7
7-19
19-46
46-65
65-95
95-130
130-155
Al
0 -7
7-14
14-27
27-36
36-50
50-70
70-92
92-109
109-142
142-155
155-170
Al
0 -7
7-16
16-27
27-42
42-91
91-120
120-135
135-153
153-175
Al
0- 6
6-18
18-35
35-51
51-90
90-133
133-163
A2
A3
BA
Bwl
Bw2/2Crt
2Crt
A2
A3
AB
B/E
E/B
2Bt1
3Bt2
3Bss
4BCtl
4BCt2
A2
cl
cl
cl
cl
cl
sicl
sic
27.8
28.2
30.4
29.5
29.1
32.1
41.2
48.2
48.3
47.4
48.3
47.7
52.9
52.9
sil
sil
25.0
26.5
28.5
31.2
31.4
32.9
56.0
58.2
57.3
27.7
34.9
52.7
50.7
49.2
48.7
48.1
47.9
35.2
30.2
30.2
43.8
36.3
Site #2
22.3
22.8
22.3
20.1
20.5
19.2
8.8
11.6
12.5
28.5
28.8
25.0
26.6
30.5
38.2
61.5
61.5
60.7
59.3
31.7
53.7
53.3
49.3
45.2
28.9
28.3
29.3
30.4
61.8
Site #3
21.3
20.1
20.2
16.6
9.6
10.2
10.0
10.3
6.5
43.8
47.4
52.4
54.5
56.1
58.8
62.0
46.4
44.8
37.2
33.7
36.9
33.9
32.2
cl
cl
cl
sicl
sic
c
c
cl
cl
sil
sil
B/E
E/B
cl
2Bt
3Bss
c
c
3Bsstyl
c
3Bssty2
4BCt
c
Al
sic
sic
A2
AB
BA
sicl
sicl
c
Bt
c
c
Bssl
c
Bss2
24.0
23.5
22.2
22.2
23.2
15.0
5.9
Site #4
9.8
7.8
10.4
11.8
7.0
7.3
5.8
9.0
9.1
9.6
8.9
8.2
8.5
15.5
3.0
3.1
3.1
3.2
3.1
4.5
10.0
0.045
0.040
0.039
0.045
0.034
0.085
0.080
0.162
0.142
0.128
0.153
0.117
0.265
0.194
0.047
0.035
0.025
0.026
0.027
0.024
0.149
0.156
0.166
0.188
0.132
0.088
0.083
0.086
0.073
0.266
0.268
0.290
0.37
0.36
0.34
0.35
0.32
0.34
0.61
0.62
0.63
0.59
0.54
3.4
42.7
42.7
33.8
28.6
10.5
0.42
0.43
0.45
0.48
0.69
0.69
0.56
0.48
0.33
3.5
3.7
3.4
3.7
4.0
3.8
3.9
4.0
10.5
0.061
0.037
0.026
0.025
0.184
0.190
0.188
0.180
0.244
0.139
0.085
0.065
0.299
0.309
0.310
0.304
23.5
26.4
29.9
30.7
29.1
24.9
23.2
0.54
0.56
0.57
0.56
0.52
0.42
0.37
5.7
6.7
4.6
3.9
6.3
5.6
6.6
0.116
0.085
0.137
0.105
0.075
0.152
0.176
0.265
0.179
0.261
0.193
0.134
0.259
0.284
9.3
9.6
9.8
10.8
10.1
11.1
34.4
35.9
36.0
16.3
18.8
10.5
11.5
13.8
18.2
Abbreviations taken from Soil Survey Staff (1993) unless otherwise noted
** COLE = coefficient of linear extensibility
^LEP = Linear Extensibility Percent
0.32
0.32
0.32
0.30
0.28
0.26
0.38
3.2
3.2
3.4
3.3
3.5
5.0
3.6
3.4
2.5
2.3
Table 2.4. Chemical characteristics of the study area soils.
Depth
Horizon
(cm)
pH
Exch. Active
pH
cliff.
Orgn C
wt pct
Orgn M
wt pct
Dithionite-Citrate Extractable
Fe
Al
Mn
( percent on <2-mm basis)
0 -7
7-19
19-46
46-65
65-95
95-130
130-155
0 -7
7-14
14-27
27-36
36-50
50-70
70-92
92-109
109-142
142-155
155-170
Al
A2
A3
BA
Bwl
Bw2/ 2Crt
2Crt
Al
A2
A3
AB
B/E
E/B
2Bt1
3Bt2
3Bss
4BCt1
4BCt2
0 -7
Al
7-16
A2
16-27
B/E
27-42
E/B
42-91
2Bt
91-120 3Bss
120-135 3Bsstyl
135-153 3Bssty2
153-175 4BCt
0 -6
6-18
18-35
35-51
51-90
90-133
133-163
Al
A2
AB
BA
Bt
Bssl
Bss2
4.7
5.3
4.6
5.8
5.2
Site 1
6.9
1.7
7.0
1.6
7.0
2.3
7.1
1.8
7.2
2.6
7.8
2.0
5.6
0.4
4.9
4.9
5.0
4.7
4.5
4.8
4.1
4.2
4.3
4.8
5.0
Site 2
7.1
2.2
7.1
2.2
7.0
2.0
6.3
1.6
6.9
2.4
6.0
1.2
4.7
0.6
6.4
2.2
4.8
0.5
7.4
2.6
7.0
2.0
4.8
4.5
4.4
4.3
4.4
4.8
6.6
6.8
7.0
Site 3
5.5
0.7
5.2
0.7
5.3
0.9
5.2
0.9
4.9
0.5
5.2
0.4
6.7
0.1
7.1
0.3
7.4
0.4
5.67
2.76
1.47
0.89
0.39
0.26
0.18
0.15
0.03
9.8
4.8
2.5
4.6
4.4
4.8
5.0
5.9
7.0
6.9
Site 4
5.3
0.7
4.9
0.5
5.4
0.6
5.8
0.8
6.5
0.6
7.1
0.1
7.5
0.6
9.16
3.99
2.43
1.57
1.03
0.95
0.79
15.8
5.2
5.4
3.37
2.08
1.27
0.64
0.42
0.26
0.10
5.58
2.93
1.45
1.13
0.67
0.61
0.27
0.20
0.16
0.09
0.05
5.8
3.6
2.2
1.1
0.7
0.4
0.2
9.6
5.1
2.5
1.9
1.2
1.1
0.5
0.3
0.3
0.2
0.1
1.5
0.7
0.4
0.3
0.3
0.1
6.9
4.2
2.7
1.8
1.6
1.4
Amonium Oxalate Extractable
Fe
Feo/Fed
ratio
Al
(percent on <2-mm basis)
2.6
2.6
2.6
2.6
2.7
2.5
3.1
0.2
0.2
0.2
0.2
0.2
0.2
0.2
TR
TR
TR
TR
TR
0.29
0.29
0.27
0.22
0.26
0.30
0.35
0.23
0.23
0.22
0.17
0.17
0.20
0.26
0.11
0.11
0.10
0.08
0.10
0.12
0.11
2.2
2.7
2.6
2.9
2.9
2.9
2.6
2.8
2.9
4.8
0.9
0.2
0.2
0.3
0.3
0.2
0.3
0.2
0.2
0.3
0.2
0.1
TR
TR
TR
TR
TR
TR
0.78
0.87
0.72
0.59
0.48
0.52
0.24
0.14
0.10
0.31
0.04
0.20
0.22
0.23
0.23
0.18
0.21
0.19
0.15
0.14
0.16
0.11
0.35
0.32
0.28
0.20
0.17
0.18
0.09
0.05
0.03
0.06
0.04
2.3
2.5
2.8
2.8
2.5
2.6
2.5
2.3
3.1
0.2
0.2
0.3
0.3
0.3
0.2
0.2
0.1
0.2
0.1
0.1
0.1
TR
0.74
0.82
0.65
0.48
0.22
0.24
0.17
0.17
0.11
0.19
0.20
0.24
0.23
0.23
0.16
0.14
0.14
0.13
0.32
0.33
0.23
0.17
0.09
0.09
0.07
0.07
0.04
3.6
4.5
4.8
4.7
3.8
2.6
3.1
0.3
0.4
0.4
0.4
0.2
0.2
0.2
0.3
0.3
0.4
0.5
0.4
0.2
0.2
1.66
0.36
0.42
0.45
0.35
0.34
0.33
0.37
0.45
0.39
0.29
0.24
0.26
TR
TR
TR
0.1
0.2
0.2
2.14
1.83
1.12
0.62
0.82
.
23
Textural variations and one probable discontinuity were
identified in the field and speculations made about possible additional
discontinuities. Particle-size distribution data were used to confirm
and identify discontinuities. A common manipulation of particle-size
data is to compute sand and/or silt separates on a clay-free basis,
since clay distribution is subject to pedogenic change (Soil Survey
Laboratory Staff, 1995). Sand is likely to be less altered by soilforming processes and weathering. Clay-free sand percentages are
shown in Table 2.3. A change from 4.5% to 10.0% between the
Bw2/2Crt and 2Crt horizons at Pit 1 indicates that a discontinuity
may exist. In Pits 2 and 3, a higher clay-free sand percentage in the
2Bt horizon suggest a discontinuity between the E/B horizons and the
2Bt horizons and a discontinuity between the 2Bt horizons and the
3Bss horizons. A third discontinuity in the soils at Pits 2 and 3 is
suggested between the 3Bss and 4BCt horizons.
The clay-free sand percentages also point to some mineralogical
differences in the bedrock that underlies the backslope and upper
footslope. The bedrock at Pits 1 and 3 have approximately 10% clayfree sand while Pit 2 sandstone has an average of 2.4 percent. The
difference is likely due to the interbedding of sandstone and siltstone.
Another method that can aid in the examination of soil
development and properties uses the fine-clay (<0.2 p.m) fraction. The
ratio of fine-clay (colloidal) to total clay in Table 2.3 can be used to
determine the presence of illuvial clay (Soil Survey Laboratory Staff,
1995). The ratio of fine-clay to total clay is normally at least one-third
higher in an illuvial argillic horizon compared to the overlying or
underlying horizons.
The 2Bt1 and 3Bt2 horizons of Pit 2 showed a large absolute
increase, 23% and 20% respectively, in fine-clay from the overlying
eluvial horizon and the underlying 4BCt horizons with a fine-clay to
24
total clay ratio increase of 80% from the overlying horizons. The 2Bt
horizon in Pit 3 had a similar absolute increase in fine-clay but a
smaller ratio increase of 44%. The ratios when considered alone could
indicate the clay horizons are argillic. However, when considered with
the discontinuities, the large ratio increase in the 2Bt horizon suggest
the clay is from stratification and not from illuviation. Pit 4 soils show
a very slight increase in fine-clay and in the fine-clay to total clay ratio
to 35 cm and then both start to decrease with depth. The slight
increase does not indicate illuviation.
Slickensides, which were noted in the clay horizons of Pits 2, 3,
and 4 during field characterization, were investigated with lab
analysis. COLE (Table 2.3) is a "value that denotes the fractional
change in the clod dimension from a dry to a moist state" and can be
used "to make inferences about shrink-swell capacity and clay
mineralogy" (Soil Survey Laboratory Staff, 1995). Values up to 0.17
cm/ cm in Pit 2 and up to 0.19 cm/ cm in Pit 3 clay horizons indicate
an abundance of expandable clay minerals. In addition, the ratio of
linear extensibility percent (LEP) to total clay percent indicates that the
clay horizons are very smectitic (>0.15).
COLE values for the soil horizons in Pits 1, 2, and 3 range from
low (<0.03 cm /cm) to high (0.06-0.09 cm/cm) shrink-swell classes.
COLE values for soils of Pit 4 indicate high levels of shrink-swell clays
for all horizons. Erratic values for soils in Pit 4 are probably from the
nature of the different alluvial deposits.
Soil organic matter content (Table 2.4) was calculated from
organic carbon content. Organic carbon content can be used as an
indirect measurement of organic matter (Soil Survey Laboratory Staff,
1995). The "Van Bemmelen factor" of 1.724, which is based on the
assumption that organic matter contains 58% organic C, was used for
the conversion.
25
The organic matter content of all the soil pits shows a trend of
increasing organic matter content downslope. Pit 1 soils have 5.8%
organic matter in the upper 7 cm. Pit 2 soils have 9.6% organic
matter content in the upper 7 cm and 5.1% to 14 cm. Pit 3 soils have
9.8% in the upper 7 cm and 4.8% to 16 cm. Both Pits 2 and 3 have
2.5% organic matter down to 27 cm. Pit 4 soils have 15.8% in the
upper 6 cm with over 4% down to 35 cm.
The abundance of organic matter in these soils is likely due to
the dominant vegetation that consist of a variety of annual and
perennial grasses (Oades, 1988). The increase of organic matter
content downslope is due to the increase in soil moisture and duration
of saturation that slows decomposition of organic matter (Oades,
1988).
Soil solution pH (1:1 water) and exchangeable pH (1:2 CaC12)
were determined for each horizon of the four pedons (Table 2.4) at the
NSSL from samples taken during the dry summer season. Soil
solution pH (active pH) ranges from moderately acid to slightly alkaline
(5.6 to 7.8) at Pit 1 and very strongly acid to slightly alkaline (4.7 to
7.5) at Pits 2, 3, and 4. The exchangeable pH ranges from extremely
acid to neutral (pH 4.1 to 7.0).
Comparison of pH between soils of Pit 1 and Pit 2 show a
decrease in pH in Pit 2 subsurface horizons. Comparison of pH
between soils of Pit 2 and Pit 3 show a decrease in pH in Pit 3 surface
and subsurface horizons. The decrease in pH could be the long-term
result of reduction-oxidation processes. A decrease in pH can occur
from a process called ferrolysis where displaced cations are replaced
by exchangeable Fe2+ ions and lost by leaching or lateral flow. Upon
oxidation, H+ replaces the adsorbed Fe2+ ion and within days is
replaced by A13+. In this system, "exchangeable Fe2+ is the immobile,
potentially acid component" (van Breemen, 1988b). In some reductive
26
reactions, the reduction of iron consumes less hydrogen ions than the
oxidation of iron produces, which can result in a long-term net
increase in acidity as shown by the following reactions:
1 /24 C6H1206(aq) + Fe0OH(s) +1 3/4 H+(aq) =
Fe2÷(aq)
Fe2+(aq)
1/4 HCO3- (aq) + 1 3/2 H20(1)
1/4 O2(g) +1 1/2 H20(1) = Fe0OH(s) + 2H+(aq)
Usually, exchangeable pH is 0.5 to 1.5 units lower than active
pH due to the salt cations (CaC12) putting exchangeable aluminum into
solution and subsequent hydrolysis (Foth and Ellis, 1988; Soil Survey
Laboratory Staff, 1995). Soils at Pit 3 and Pit 4 were within the
expected 0.5 to 1.5 unit change, but soils at Pit 1 and Pit 2 had a
difference in pH up to 2.6 units lower in some horizons. The large
change between the pH values may indicate a relatively large amount
of Al in the soils in Pits 1 and 2. Although acid soils with pH 5.5 or
more have little exchangeable aluminum (A13+), hydrolysis of hydroxy
forms of Al can be a major source of hydrogen ions between pH 4 and
7.5 (Foth and Ellis, 1988).
Chemical dissolution analysis performed on the soils included
dithionite-citrate extractable Fe, Mn, Al and ammonium oxalate
extractable Fe and Al (Table 2.4). Dithionite-citrate extractable iron
(Fed) is considered a measure of the "free" Fe oxides or total pedogenic
Fe in the soil (Soil Survey Laboratory Staff, 1995). Ammonium oxalate
extractable iron (Feo) is considered a measure of the poorly crystalline
Fe (Schwertmann, 1988) . The Fe./ Fed ratio gives an approximation of
the relative proportion of ferrihydrite (Schwertmann, 1988).
All four pedons at the study site contain an appreciable amount
(2.2% to 4.8%) of iron oxides (Fed). The soils of Pits 1, 2, and 3 have
values between 2.2% and 3.1% and Pit 4 has the highest values that
range up to 4.8%.
27
The B/E and E/B horizons of Pits 2 and 3 have segregated areas
of high and low chroma colors, which indicate repeated periods of
reduction, translocation, and oxidation of iron and manganese.
However, the redistribution of iron appears to be occurring within the
depleted horizons. The iron oxide (Fed) content of 2.9% and 2.8%,
respectively, indicates that Fe2+ iron is not being translocated out of
the horizons. In fact, the data infers a slight increase in iron content
compared to the horizons above and below.
The results were unexpected since slope and soil heterogeneity,
which are associated with hydraulic properties, promote subsurface
lateral flow (throughflow) (Zaslaysky and Rogowski, 1969) and lateral
translocation of Fe2+ iron (Blume, 1988). There may be some vertical
movement of Fe2+ either by eluviation from the surface horizons or by
upward movement of Fe2+ toward higher 02 partial pressures from
lower wetter horizons.
Another possibility is that translocation of Fe2+ by lateral flow
from upslope is greater than the amount of Fe2+ ions being
translocated out. The hillslope's geomorphic and geometric
components could be contributing to this phenomenon. The hilislope
at Sites 2 and 3 is a concave-linear footslope compared to convexlinear backslope at Site 1. Flow lines of infiltrating water converge in a
concave landscape position (Ruhe, 1975) and the break in slope with a
decrease in relief would slow down the rate of flow (Whipkey and
Kirkby, 1978) and could create a "sink" for Fe that is being
translocated from upslope.
The clay horizons of Pits 2 and 3 have a 2.5Y hue that is often
associated with soils that have low free-iron content (Daniels et al.,
1960). However, the clays have high free-iron content ranging from
2.3% to 2.9%. We can infer from the data that the color in the clay
horizons is inherited from the primary minerals of the parent material
28
in which they were formed. Since the clay horizons have the same hue
as the underlying sandstone, residual formation was considered.
However, the particle-size distribution, particularly the clay-free sand
percentage, indicates that the clays are not residuum. Further
investigation on discontinuities and source of the clays is discussed in
Chapter 6.
In soils of Pits 2 and 3, the increase in the relative proportion of
ferrihydrite (Feo/Fed) correlates with the increased organic matter
content and redoximorphic features. Soil surface and subsurface
horizons have two to seven times as much ferrihydrite as the clay
substratum. In addition, soils in Pits 2 and 3 have two to three times
more ferrihydrite than the soils in Pit 1. The increase downslope of
ferrihydrite is attributed to an increase in reducing conditions. Blume
(1988) and Van Breemen (1988b) indicated that in many cases a larger
fraction of poorly crystalline Fe oxide (Feo) was found in environments
that had seasonally saturated soils.
Dithionite-citrate extractable manganese (Mnd) (Table 2.4) is
considered the "easily reducible Mn" (Soil Survey Laboratory Staff,
1995). Only trace amounts of manganese were in the soils of Pits 1
and 2. Manganese content increased downslope starting in Pit 3 soils
and reached high levels (>0.2%) (Ponnamperurna, 1972) in Pit 4 soils.
The trend could indicate that manganese is extensively redistributed
within the landscape. Manganese is reduced at a higher redox
potential than iron (Gotoh and Patrick Jr, 1972) and thus is more
mobile. A study by McDaniel et al. (1992) showed that Mn is
distributed independent of silicate clay and Fe oxides and generally
increases downslope. However, the higher levels of manganese in the
soils at Pit 4 could also partially be due to manganese inherited from
alluvial parent materials.
29
Dithionite-citrate extractable aluminum (Ala) and ammonium
oxalate extractable aluminum (Al.) data are listed in Table 2.4. Ala
represents the aluminum substituted in Fe oxides (Schwertmann and
Taylor, 1989) while Al. is an estimate of the total pedogenic aluminum
in allophane, imogolite, and organically bound aluminum (Soil Survey
Laboratory Staff, 1995).
Comparison of the Ala and Al. data suggests that a majority of
the aluminum in the soils is complexed with iron oxides. Substitution
of Al for Fe in goethite is common (Norrish and Taylor, 1961) and can
range up to 33 mole percent (Schwertmann and Taylor, 1989).
According to Schwertmann (1988), the extent of Al substitution reflects
the activity of Al in a system and the activity of Al is controlled by
factors such as pH, type of Al compound, stability of Al-organic
complexes, and silicate activity.
Mineralogical
The mineralogical characterization by the National Soil Survey
Laboratory (Appendix A) shows the mineralogy of selected horizons for
the <21-1,M fraction. The fine-clay mineral assemblage indicates that
the soils are smectitic with lesser amounts of vermiculite, interlayered
smectite, mica, and kaolinite.
Supplemental X-ray diffraction analyses were run on random
powder mounts of the Pit 1, 2, and 3 sandstone samples and a sample
of the 3Bsstyl clay horizon from Pit 3. The diffractograms of the
sandstone samples (Fig. 2.3) show that Pit 1 2Crt, Pit 2 4BCt 1, and Pit
3 4BCt horizons have small peaks at 3.06-3.08A and 2.87A that may
be gypsum. The 3l3ssty 1 clay horizon of Pit 3, where the highest
accumulation of gypsum was noted (Fig. 2.4), differs from the
sandstone horizons in that the sample shows sharp intense peaks at
7.61A and 3.06A.
Figure 2.3. Random powder mount XRD patterns of weathered bedrock samples from Pits 1, 2, and 3.
[1] Gypsum - CaS0412H20
7500
S 5000
0
C
C
2500
Pit 2-413Ct1
Pit 3-4BCt
10
20
30
40
2-Theta(deg)
50
60
Figure 2.4. Random powder mount XRD pattern of the 3Bsstyl clay horizon.
[1] Gypsum - CaSO4!2H20
400035003000-
-3 2500c
0
Pit 3-3Bssty1
5 2000
ca)
1500-
1000500-
10
20
2-Theta(deg)
32
To confirm the identification of gypsum, scanning electron
microscopy (SEM) was performed on the 3Bssty 1 clay sample from Pit
3. The SEM scan shows very large crystals (Fig. 2.5a) concentrated
within the soil matrix and in some instances engulfing the matrix
within the crystal structure (Fig. 2.5b). The accompanying X-ray
energy spectrometry (Fig. 2.6) shows that the crystal mineralogy is
mainly calcium sulfate and that the soil matrix is completely void of
any microscopic calcium or sulfate.
Gypsum (CaSO42H20) is the most common sulfate mineral in
soils (Doner and Lynn, 1977) but is an anomaly for the subhumid
Willamette Valley soils. Gypsum can be either lithogenic or pedogenic.
Lithogenic gypsum is inherited from the parent material. Pedogenic
gypsum is formed as a secondary product of pedogenic processes
(Hallmark, 1985).
Although improbable, lithogenic evaporates may have formed in
the basin sediments of the Willamette Valley during the Miocene-
Pliocene periods. Gradual uplifting of the coast and filling of the basin
with sediments caused a gradual retreat of the ocean shoreline before
the valley became separated from the ocean (Orr et al., 1992).
Evaporation in a chemical system receiving new solution from the sea
usually results in gypsum, anhydrite and some halite evaporites
(Williams et al., 1954). However, high rates of evaporation were
unlikely in the moist semitropical environment (Orr et al., 1992) that
existed. In addition, any evaporites would have leached from the soils
in Oregon's wet climate.
A pedogenic origin is a more plausible hypothesis. Pedogenic
gypsum could originate from marine sandstones that were once
reducing in chemical character. Snavely Jr. and Wagner (1963) state
that it was likely that a nearshore environment existed along the
eastern margin of the present Willamette Valley during the late
33
Figure 2.5. SEM micrographs of gypsum crystals and clay matrix
from the 3Bsstyl horizon. (a) Gypsum crystals.
(b) Crystals engulfing matrix.
(a)
(b)
34
Figure 2.6. X-ray energy spectrometry of the crystals and matrix from
the 3Bsstyl horizon. (a) Crystal mineralogy. (b) Matrix
mineralogy.
(a)
(b)
0
Cursor=
Vert=366
Window 0.000 -40.950=
17737 cnt
35
Eocene. They found beds of massive arkosic and volcanic sandstones
containing interbedded carbonaceous siltstone along the southeastern
margin of the basin. These Eocene beds were formed in shallow-water
marine and brackish-water environments. Tidal flats probably formed
along the retreating edges of the ancient Pacific shoreline providing
organic accumulations and some areas of stagnant marine waters.
Under this type of reducing marine environment, along with iron and
sulfate rich sediments, pyrite (FeS2) could form (Doner and Lynn,
1977). Once the sea had receded, 02 would have started to oxidize the
pyritic exposed sediments. Acid sulfate soils and jarosite are usually
the result (Doner and Lynn, 1977). However, if calcium carbonates or
other Ca-bearing materials (Ritsema and Groenenberg, 1993) are
present, acidity is neutralized and gypsum forms. It is also possible
for jarosite and gypsum to occur together (Doner and Lynn, 1977).
Van Breemen (1982) described jarosite as a pale yellow (2.5-5Y 8/38/6) mineral that forms only in an acid (pH 2 to 4) environment, but
can persist for decades at pH values above 4 and eventually hydrolyze
to goethite.
A third possibility is that the volcanic basalt foundation under
the sandstone formation is influencing the chemical properties in the
lower solum. The basalt foundation could be cracked and broken by
faults and joints from tensions created during the subduction of the
Juan de Fuca plate beneath the North American plate. Water
movement through the network of faulting could provide the
sandstones with a source of sulfur from dissolution of pyrite when the
groundwater table rises. Combined with the calcium from plagioclase
feldspars in the arkosic sandstones, gypsum could form.
In summary, gypsum accumulation in the lower clay horizons
and traces of gypsum in the sandstones is likely attributed to the
stratified arkosic sandstones and interbedded sulfate rich siltstones.
36
Most of the gypsum is probably seasonal with the calcium sulfate
being brought up into the lower clay horizons from the sandstones
with the seasonal rise in water table levels. The gypsum diffuses to
and precipitates in the aerated cracks caused by the high shrink-swell
clays during the dry summer season. Retention of the gypsum in the
moist Willamette Valley climate is probably due to the hillslope's
stratigraphy that has restricting clay horizons, which prevents deep
leaching.
Classification
The soils on the upper transect (Pits 1, 2, and 3) were originally
classified by the Soil Conservation Service as fine, mixed, mesic Ultic
Haploxerolls and very fine, mixed, mesic Aquultic Haploxerolls (Soil
Survey Staff, 1975a). The soils on the lower transect (Pit 4) were
classified as very fine, montmorrillonitic, mesic Typic Pelloxererts.
According to current morphologic features and characterization, the
soils were classified as: Ultic Haploxerolls for Pit 1, Aeric Humaquepts
for Pit 2, Vertic Epiaquepts for Pit 3, and Typic Endoaquerts for Pit 4.
Conclusion
High chromas and few iron redox features indicate very short
periods of saturation and reductive conditions in soils at Site 1.
Redoximorphic concentrations within 7 cm of the soil surface in soils
of Pits 2 and 3 and concentrations at the surface in soils of Pit 4 show
that iron and manganese are being reduced and oxidized high within
the soil profile. The presence of iron masses composed of ferrihydrite
and lepidocrocite suggests a reducing environment with periodic
saturation for long durations.
37
In comparing the surface and subsurface soils of Pits 1, 2 and 3,
the increase in the relative proportion of ferrihydrite (Feo /Fed)
correlated with increased organic matter content and redoximorphic
features. Manganese content varied according to landscape position.
Only trace amounts of manganese (Mai) were in the soils of Pits 1 and
2 on the upper transect. Manganese content increased downslope
starting in Pit 3 soils and reached high levels (>0.2) in Pit 4 soils.
Field morphological investigation suggested the presence of one
and possibly more discontinuities. Physical analysis confirmed the
presence of three discontinuities on the upper transect. Horizons with
zones of depletion over clay horizons and evidence of a discontinuity
suggest that the low hydraulic conductivity of the clays on the upper
transect restricts vertical water movement and creates a seasonal
perched water table.
The clay horizons of Pits 2 and 3 have the same hue as the
underlying sandstone but the particle-size distribution indicates that
the clays are probably not residuum. Further investigation on the
source of the clays is discussed in Chapter 6.
Soil morphologic features and soil characterization data provide
for some contrasting preliminary interpretations at Sites 2 and 3. Low
chroma and high (?_4) value matrix colors that occur in subsurface
horizons indicate zones of iron depletion. However, dissolution
extractions indicate the amount of pedogenic iron in the AB, B/E, and
E/B horizons of Pit 2 and the B/E and E/B horizons of Pit 3 is slightly
higher than in the horizons above or below. Possible causes could be
from the eluviation of Fe2+ from surface horizons, upward diffusion of
Fe2+ toward higher 02 partial pressures, and translocation of Fe2+ by
lateral flow from upslope along with the decrease in flow rate due to
the concavity of the slope at Sites 2 and 3.
38
Soil morphology, along with physical, chemical, and
mineralogical data, suggests a complex stratigraphic and pedogenic
history resulting in soils with pedogenic features superimposed across
several lithologic discontinuities.
39
Chapter 3
HYDROLOGIC REGIME AND REDUCING ENVIRONMENT AT THE
WITHAM HILL BACKSLOPE-FOOTSLOPE STUDY SITE
Introduction
Currently, the hydric soil definition defines hydric soils as soils
"that formed under conditions of saturation, flooding, or ponding long
enough during the growing season to develop anaerobic conditions in
the upper part" (Federal Register, July 13, 1994). The definition
encompasses duration of saturation, depth to saturation, presence of
anaerobic conditions, and soil temperature, which are important
factors in both the formation and verification of hydric soils.
The objective of this chapter is to examine these factors through
a detailed characterization of the hydrology and reducing environment
of the study site soils to determine if the soils are hydric according to
the hydric soil definition issued by the National Technical Committee
for Hydric Soils (NTCHS).
Background
General
The NTCHS Technical Standard Committee is currently working
on technical standards to clarify the definition of hydric soils and
provide measurable specifications to evaluate when the definition has
been met (US Department of Agriculture, Natural Resource
Conservation Service, 1995). The National Technical Committee for
Hydric Soils (1996) has proposed that the "upper part" be defined as
less than 30.5 for loamy or finer textured soils and less than 15 cm for
sandy soils. The National Research Council (1995) indicates, based on
available data, that "reasonable hydrologic thresholds would include a
40
depth to water table of < 1 ft (30 cm) for a continuous period of at least
14 days during the growing season, with a mean interannual
frequency of 1 out of 2 years." The council concluded that the
thresholds are consistent with those defined for formation of hydric
soils according to Hydric Soils of the Unites States (US Department of
Agriculture, Soil Conservation Service, 1991).
Growing season, in determining hydric soils, is defined as "the
portion of the year when soil temperatures are above biologic zero in
the upper part" (US Department of Agriculture, Soil Conservation
Service, 1991). Biological zero is at 5°C (41°F) (Soil Survey Staff,
1975b) at 50 cm beneath the soil surface (National Technical
Committee for Hydric Soils, 1996) and is considered the threshold that
biological activity is assumed to be negligible.
Hydrology
Hydrology is recognized as the driving force behind the
development of hydric soils. The hydrologic parameters for
determining hydric soils are defined in terms of duration of continuous
saturation, flooding, or ponding within a given distance of the soil
surface during the growing season.
Saturated soil conditions are normally considered to exist when
pores are filled with water and the pore water has zero pressure (at the
water surface) or positive pressure (below the water surface). Negative
pressure occurs above the water table (water surface) in the
unsaturated zone. However, saturation can extend above the water
table in a tension-saturated zone (negative pressure) called the
capillary fringe (Freeze and Cherry, 1979; Stephens, 1996). The
capillary fringe zone can range from 10 cm in very coarse material to
greater than 100 cm in fine-textured clays (Stephens, 1996). But for
41
surface horizons, consideration must be given to large pore spaces
created by flora and fauna that decrease capillary rise (National
Research Council, 1995). Thus, in most cases, the water table is
considered a reasonable approximation of the saturated zone.
Field piezometers, which are open to water flow at the bottom
and to the atmosphere at the top, can be used to measure the
elevation of groundwater. Height of a water column in a piezometer is
an indication of the pressure potential of pore water and is expressed
as pressure head (Hillel, 1980). Freeze and Cherry (1979) define a
water table as the free surface in the soil-groundwater system where
pore water is at atmospheric pressure. The surface of a column of
water in a piezometer is at atmospheric pressure and has zero
pressure head. In unconfined aquifers and perched aquifers, the
surface is called the piezometric surface, which can be used as an
indication of water table levels (Freeze and Cherry, 1979).
Piezometers can not measure negative pressure potentials and,
therefore, can not be used to measure the capillary fringe. The
capillary fringe in which pores are saturated by capillarity and the
water held by surface tension (Bouma et al., 1974; Hillel, 1980) can be
measured by tensiometers, which measure matrix potential (Freeze
and Cherry, 1979; Hillel, 1980).
Zones of saturation can be a major factor in the genesis of a
soil's morphology and development of hydric soils. Saturation can be
continuous from the upper to the lower horizons, restricted to horizons
near the surface due to slowly permeable horizons, or upper and lower
saturated horizons can be separated by a layer without free water.
The International Committee on Soils with Aquic Soil Moisture
Regimes defines soils that are saturated in all layers from the upper
boundary of saturation to a depth of 2 m or more, as having
endosaturation (Vepraskas, 1994). This type of saturation usually has
42
oxidized conditions above reduced horizons. Soils that are saturated
in layers above unsaturated layers within a depth of 2 m have
episaturation. Perched water tables formed over horizons having low
saturated hydraulic conductivity are characteristic of episaturation.
Both epi- and endosaturation can occur when a perched water table is
present above an aerated zone that has a rising groundwater table
beneath (Dudal, 1990).
Reducing Environment
Although the hydric soil definition is based on anaerobic
conditions (reduction and removal of molecular oxygen), there is still
debate about whether the hydric soil concept should be based on the
depletion of oxygen (anaerobiosis) or more intense reducing
environments involving the reduction of iron. The reduction of iron
has become the accepted parameter for characterizing anaerobic
environments in morphological evaluations and an alternate threshold
for research (Bohn, 1971). The absence of oxygen in the field is not
verifiable without installed equipment, but the hydrologic and
reducing environment can be inferred from morphological properties
related to the reduction-oxidation of manganese and iron.
The reducing environment is influenced by oxygen supply,
microbial community, organic matter, pH, soil temperature, and
abundance of electron donors (Gambrell and Patrick Jr, 1978).
Development of anaerobic conditions occurs when the soil is near
depletion or depleted of molecular oxygen. The depletion of oxygen in
saturated soils is caused by biological activity. Oxygen is used by
microorganisms (mainly bacteria) in the obtainment of chemical energy
and the process involves oxidation-reduction reactions (Rowell, 1981).
As heterotrophic aerobic and facultative microbes decompose organic
43
matter (oxidation reaction) for an energy source, they utilize oxygen as
the electron acceptor (reduction reaction). In saturated soils, the
diffusion rate of oxygen is 104 times slower than diffusion in the
gaseous phase and microbes demand for oxygen exceeds supply
(Rowell, 1981).
Once all 02 has been reduced, heterotrophic facultative and
anaerobic microbes use alternate inorganic soil components as
electron (hydrogen) acceptors (Ponnamperuma et al., 1967; Gambrell
and Patrick Jr, 1978). Microbes continue to oxidize organic matter in
a thermodynamic sequence of reduction-oxidation (redox) reactions
involving the reduction of NO3-, Mn4+, Fe3+, and 5042- (Turner and
Patrick Jr, 1968; van Breemen, 1988a; Ponnamperuma, 1972; Patrick
and Jugsujinda, 1992). Iron has been found to play a dominant role
in periodically wet soils since it is usually the dominant oxidant in the
absence of oxygen (van Breemen, 1988a). Reduction of these minerals
affects their solubility, movement, and concentrations (Rowell, 1981;
Bohn et al., 1985; van Breemen, 1988b).
Transfer of electrons in redox reactions creates an
electrochemical potential that can be measured. The electron activity
(pE) can be measured electrically in reference to a standard substance,
(H2), and is commonly referred to as redox potential (Eh) (Rowell,
1981). The Eh is defined as the energy gained in the transfer of 1 mole
of electrons from an oxidant to hydrogen (Freeze and Cherry, 1979)
and is related to the distribution of ion oxidation states by the Nernst
equation at equilibrium conditions (Bohn, 1971):
Eh (volts) = Eh° + RT in Joxidant]
nF [reductant]
Eh° = standard potential of the redox couple
F = faraday constant
R = gas constant
T = absolute temperature in Kelvin
n = number of transferred electrons
44
The most widely accepted method to measure redox potentials in
soils is with permanently installed platinum electrodes. The electrode
potential is a measurement of the tendency of a substance to donate
or accept electrons (Bohn et al, 1985). According to Bohn (1971), soil
redox potentials cannot be quantitatively evaluated in terms of
individual redox couples due to mixed couple potentials in the
nonequilibrium system. A redox potential is a semi-quantitative
measurement (Ponnamperuma, 1972) of a mixed potential that is the
weighted average of all redox couples present in the system (Bohn,
1971). Platinum electrodes are used because platinum is responsive
to changes of redox conditions in natural systems and platinum is
"inert", responding only to the potential of the electrons. Redox
couples affect the mixed potential in proportion to their ability to
exchange electrons with the electrode surface (Bohn, 1971).
As microbes utilize the sequence of electron acceptors, the redox
potential lowers due mainly to redox couples that have lower affinity
for electrons (Rowell, 1981). The redox potential also depends, in part,
on pH, soil temperature, and the concentrations of reactants (Rowell,
1981). The concentration of reactants is especially important since the
final potential is determined by the system which is in excess
(Ponnamperuma, 1972).
A soil's hydrogen ion activity (pH) influences mineral equilibrium
which regulates the dissolution and precipitation of solids, the
sorption and desorption of ions, and the concentration of ions
(Ponnamperuma, 1972). Therefore, interpretation of Eh
measurements needs to include the pH factor. In general, a higher soil
pH requires lower redox potentials for the reduction of Mn and Fe
oxides.
In addition, when soils become saturated and anaerobic, the pH
changes and stabilizes between pH 6 and 7 after a few weeks or
45
months (Ponnamperuma, 1972). The increase of pH in acid soils is
the consequence of chemical reduction of acidic or inert components
to their basic or weekly acidic counterparts and to the formation of
ionic Fe2÷ that involves consumption of H+ (van Breemen, 1987). The
increase is due mostly to the reduction of iron since Fe oxides are
usually more abundant than other oxidants (Ponnamperuma, 1972).
The decrease of pH in alkaline soils is due to the accumulation of CO2,
which usually exceeds the pH-increasing effect of iron reduction (van
Breemen, 1987).
To remove pH variability between soils and obtain a common
threshold for reduction analysis, redox potentials usually are adjusted
to pH 7. However, the adjustment factor is still under debate.
Stability of solids in equilibrium with their soluble forms is expressed
by Eh-pH diagrams (stability field diagrams). Theoretical Eh-pH
diagrams based on thermodynamics have been established for the
redox equilibria of manganese and iron (Ponnamperuma et al., 1967
and 1969; Collins and Buol, 1970a) and provide a negative Eh/pH
slope of 177mV per pH unit for equilibrium conditions.
Some researchers have had poor agreement with the theoretical
relationships. Collins and Buol (1970b) found that results in soils
with rapid rates of ion movement under mass-flow and conditions of
slow oxidation disagreed with theoretical equilibrium predictions.
Ponnamperuma (1972) concluded thermodynamic relationships could
be developed only for soil solutions whose potentials are equilibrium
potentials but not for soils whose potentials are mixed.
Some researchers have used an adjustment factor of -59 mV in
Eh for each pH unit change from pH 7. The factor, which is based on
the change in Eh between a buffered pH 4 and pH 7 solution, has
become an accepted adjustment for soil potentials even though the
value has not been thoroughly evaluated insitu (Bohn, 1971). The
46
NTCHS Technical Standard Committee currently is investigating a
recommended Eh-pH slope.
Many laboratory experiments and some in situ studies have
been done to determine critical redox potentials at which reduction of
nitrate, manganese compounds, and iron compounds occur.
Manganese and iron reduction has been found to occur within a wider
range of Eh values than the start of nitrate reduction. Turner and
Patrick Jr (1968) found that the point of oxygen depletion and the
beginning of nitrate reduction in 10 soil-water suspensions (corrected
to pH 7 by the -59 mV per unit pH change) was within +300 to +350
mV. The authors found the greatest amount of reducible Mn at a
potential of +200 mV. Patrick Jr and Jugsujinda (1992) found oxygen
depletion occurred at +350 mV in their study on redox potentials in
soil-water suspensions with a pH maintained at 6.5. The authors had
thresholds of +200 mV for the appearance of Mn(II) and +100 mV for
Fe2+. Gotoh and Patrick Jr (1972,1974) reported Mn reduction
between potentials of +300 mV and +200 mV in soil-water suspensions
regulated at pH 6 and pH 8 and Fe reduction at potentials between
+300mV and +100mV in soil-water suspensions regulated at pH 6 and
pH 7. Patrick Jr and Henderson (1981) had critical redox potentials
for Mn between +250 and +200 mV and iron at +100 mV for soil-water
suspensions held at a constant pH 7. Bohn et al. (1985) gave a range
of +400 to +200 mV for Mn potentials and +300 to +100 mV for Fe
potentials but noted the potentials were measured over a range of pHs.
Cogger et al. (1992), in an in situ study, reported Fe2+ in soils at
potentials below +200 mV with unadjusted pH values between 6 and
7. Austin (1997) found detectable levels of Fe2+ with colormetric
indicators at +300 mV in some Willamette Valley soils.
As can be seen, an attempt to define critical threshold potentials
has not been successful. An important point made by Ponnamperuma
47
(1972) is that studies done in soil-water suspensions came closer to
obtaining the expected theoretical relationships than studies done in
soils.
A soil can be saturated without becoming anaerobic if the
environment is unfavorable for organisms such as low organic matter
content, low soil temperatures, pH, or if the water is aerated by
movement (Daniels et al., 1973). In addition, rates of oxygen depletion
and reduction reactions are controlled in large part by the amount of
organic matter and soil temperature. Studies have shown the
importance of organic matter content on microbial activity and
dissolution of iron and manganese. Meek et al. (1968) observed lower
Eh values with the addition of organic matter to soils. Dobos et al.
(1990) found that the addition of organic carbon had a marked affect
on iron reduction and chroma colors under alternating oxidizing and
reducing conditions. Couto et al. (1985) found that the lack of an
energy source in the substrata prevented iron reduction.
Soil temperature influences diffusion rates, biological activity,
and the rate of redox potential depression. Bonner and Ralston (1968)
observed decreased microbial activity and a decline in redox potentials
in saturated soils as soil temperatures decreased. Meek et al. (1968)
subjected organically amended soils to higher temperatures and found
a substantial increase in microbial activity and higher quantities of
reduced Mn and Fe.
The soil's anaerobic environment can, in part, be characterized
by measuring groundwater dissolved oxygen content (DO) of a soil.
Cogger and Kennedy (1992) found that horizons with DO levels <5
mg/ L for more than 80% of the time they were saturated had low
redox potentials and were reduced for part of the year. Horizons with
DO levels <5 mg/L for 60-80% of the time were reduced only in
microsites. Dissolved oxygen content of 1.5 mg/L was found by Austin
48
(1997) to be a conservative threshold for anaerobiosis in selected
Willamette Valley soils. Cogger et al. (1992) found that groundwater
dissolved oxygen data combined with soil redox measurements gave
the most comprehensive picture of the soil-ground water redox
environment.
Growing Season
The definition of growing season and its application has been
controversial and continues to be assessed. The concept of biological
zero with the assumption that biological activity and reduction
reactions cease at a specified threshold for regions with widely
differing climate can lead to errors in evaluating hydrologic data
(National Research Council, 1995). A review of studies in the Wet Soil
Monitoring Project showed that the current concept of growing season
was not applicable in most studies (US Army Corps of Engineers,
1996). The National Research Council (1995) found that a number of
studies indicated that significant microbial activities occur at
temperatures below the biological zero threshold in a wide variety of
climates.
Methods
General
Four sites (Sites 1 through 4) located approximately four meters
from the four soil pits (Pits 1 through 4) were instrumented with open
wells, nests of piezometers, permanently installed electrodes, and
thermocouples. Six additional plots (Plots A-F) were placed between
the four main sites and instrumented with a limited number of
piezometers to provide additional data on the spatially dynamic nature
49
of the hydrology. Figure 3.1 presents the layout of the instrumented
sites, plots, and adjacent excavated pits. Readings were taken weekly
during the rainy season from October through June but were
suspended from early summer to mid autumn when precipitation was
minimal and water tables fell beneath well depths. Readings were
taken on the same day of each week to ensure unbiased readings.
Complete field measurement data files are given in Appendix C.
Equipment Construction and Installation
Piezometers and Wells
Piezometers and wells were constructed following procedures
outlined by Austin (1994). Piezometers were constructed from 1.9 cm
O.D. 200psi PVC pipe. Horizontal slits were cut in the lower 8 cm of
each PVC pipe and geo-fabric was glued over the slits and open end of
the pipe to prevent clogging in situ with soil particles. A PVC cap with
a small hole drilled in its top to facilitate air entry was placed over the
top of the upper end of each piezometer.
Piezometers were installed in triplicate at 20 cm, 35 cm, and 75
cm depths at Sites 1, 2, and 3 and at 25 cm, 50 cm, and 100 cm
depths at Site 4. Plots A-F had one piezometer installed at 20 cm, 35
cm, and 75 cm depths. Placement of piezometers was determined by
random selection.
An auger hole approximately 2 cm in diameter was dug to 3 cm
beyond the desired depth for each piezometer and the bottom of the
holes filled with 3 cm of sand. The slotted ends of the piezometers
were placed in the holes and sand was poured in until the slatted
portions of the pipes were embedded in a sand layer. Bentonite was
poured in the holes around the piezometers to create a bentonite plug
50
Figure 3.1. Diagram of the instrumented sites and plots, excavated
pits and trench, and vegetation plots.
Plot A
well
piezometers
24.5 m
veg.
Site 1
well
electrodes
piezometers
thermocouples
Pit
1
16.3 m
Plot B
well
piezometers
trench
5.3 m
Plot C
well
piezometers
5.8 m
veg.
Site 2
well
electrodes
piezometers
thermocouples
Pit 2
piezometers
thermocouples
Pit 3
11 m
Plot D
well
piezometers
19.7 m
Plot E
well
piezometers
110.2 m
veg.
Site 3
well
electrodes
63.2 m
Plot F
well
Gravel Road
piezometers
36 m
veg.
Site 4 therm.
electrodes
well
piezometers
Pit 4
51
that extended to the soil surface to prevent water from running down
the sides of the pipes.
A well (open borehole) was installed at 100 cm depth at all sites.
Wells were built from 3.18 cm O.D. 160psi PVC pipe with horizontal
slits along the entire section of the pipe to be placed underground.
Geo-fabric was glued over the slits and open end of the pipe. A PVC
cap with a small air hole was placed over the open end of the well.
Auger holes were dug 3 cm beyond the desired depth and the extra 3
cm filled with sand. Each well was placed in a hole and sand was
poured around the pipe to the ground surface.
Platinum Electrodes
Platinum electrodes were constructed according to procedures
outlined by Austin (1994) and Szogi and Hudnall (1990). The
electrodes were quality checked in a pH-buffered quinhydrone solution
(Bohn, 1971). Only electrodes that varied less than plus or minus 10
mV from established test values were used. The electrodes were
installed in triplicate at 10 cm, 30 cm, and 50 cm depths at Sites 1, 2,
and 3 and at 25 cm, 50 cm, and 100 cm depths at Site 4.
Electrodes were installed by making pilot holes perpendicular
with the soil surface with a metal rod somewhat larger than the
diameter of the electrodes. The holes were made 2 cm shallower than
the desired depth. Electrodes were placed in the holes using a hollow
copper tube to push them down the hole and embed them the final 2
cm into the undisturbed soil. Pilot holes were back-filled with
bentonite and capped with 5 cm of soil. The 10 cm electrodes, due to
the shallow depth, were installed at a 36° angle to the soil surface.
The angle allowed shallow installation while still keeping the mercury
properly positioned around the copper wire. Precautions were taken to
insure no foot traffic over the installations.
52
Thermocouples
Type K, ungrounded, inconel sheathed thermocouples that were
premanufactured to four foot lengths and calibrated to plus or minus
3 degrees Fahrenheit (Austin, 1993) were used for the project. The
thermocouples were fitted with male connectors for field application.
Prior to installation, the thermocouples were tested by immersion into
a cooled liquid at a known temperature.
Installation of the majority of thermocouples was accomplished
simply by slowing pushing them into the soil to the desired depth. If
any resistance was encountered, a pilot hole was made within 2 cm of
the desired depth with a steel rod that had the same diameter as the
thermocouple. The thermocouple was then inserted and pushed the
last 2 cm into undisturbed soil. A PVC pipe with a cap at one end was
placed over the male connectors to keep them dry.
Data Collection and Interpretation
Saturation
Depth to the water surface in the piezometers was taken as a
direct indicator of the water table level. Open wells provided an
indication of saturated conditions somewhere in the soil profile. The
capillary fringe that can occur above the water table was not measured
in this study. However, when correlating hydrologic data to redox data
and morphological features this variable should be kept in mind. The
capillary fringe zone can range from 10 cm in very coarse material to
greater than 100 cm in fine-textured clays (Stephens, 1996). Austin
(1994) found that the capillary fringe ranged from 10 cm in silt loam
and silty clay loam to 20 cm in silty clay or clay soils in selected
Willamette Valley soils.
53
Depth to the water surface was determined by measuring the
distance from the top of the piezometers and wells to the standing
water surface. This was accomplished by blowing air into a metered
acrylic tube as it was lowered into each piezometer and well. The
method is similar to the one used by Hudnall and Wilding (1992).
When the tube contacted the water surface, the bubbling sound of air
through water could be heard. Measurements from the metered tube
were noted and later input into spreadsheets. The spreadsheets were
formatted to subtract the length of piezometric pipe that extended
above the soil surface for each piezometer and well from the field
measurement. The corrected reading gave the depth to the free water
surface below the soil surface. Corrected data from triplicate
piezometers at each depth were averaged for graphing and
interpretation.
Precipitation
Daily precipitation data were obtained from the Oregon Climate
Service at Oregon State University. The daily precipitation data were
averaged weekly to coincide with the weekly data readings. Weekly
averages are given in the data files in Appendix C. Rain events, for the
purpose of this analysis, refer to weekly totals.
Anaerobiosis and Iron Reduction
Reductive conditions were characterized by measuring
reduction-oxidation (redox) potentials with permanently installed
platinum electrodes. Redox potentials were taken using a portable
Radio Shack digital voltmeter and a Corning calomel reference
electrode. A salt bridge (Veneman and Pickering, 1983) between the
soil and reference electrode was created by placing the reference
54
electrode into a syringe that was inserted into moist soil and that
contained a 4 M HC1 solution. Readings were recorded as
thousandths of a volt once the millivolt reading drift was no greater
than 3 mV per minute.
The measured redox potentials were adjusted by adding +244
mV (Jones, 1966) in order to reference the potentials to the standard
hydrogen electrode (Eh). In addition, potentials were adjusted to
remove pH variability between soils and obtain a common threshold
for reduction analysis. The average pH at each measured depth for
the two field seasons and an adjustment factor of -59 mV for each pH
unit change from pH 7 was used to calculate the adjustment of redox
potentials to pH 7.
Average readings from the triplicate electrodes at each depth
were calculated and used for graphing. A redox potential of +350 mV
was used as the threshold for the onset of anaerobiosis and a redox
potential of +200 mV was used as the threshold for iron reduction.
The thresholds were chosen based on a review of redox potentials done
insitu or in soil cores.
In situ variability among some of the replicate electrodes was
high. Patterns were watched the first year and a few electrodes were
questionable. The electrodes were left in place but an additional
electrode was installed as close as possible to each of the electrodes in
question. Readings taken on the originals and replacements during
the second year showed the variability was not due to electrode failure.
Cogger et al. (1992) found that electrode variability was greater in
changing or intermediate redox environments and declined under wellreduced states indicating microsite differences. The variability in the
study site electrode readings is believed to be from microsite
differences, so the data from the original electrodes were used for the
analysis.
55
In addition to redox potentials, anaerobic conditions were
characterized by groundwater dissolved oxygen (DO) measurements.
The DO measurements were taken in the soil water of each
piezometer. The piezometers were pumped and allowed to recharge
with fresh ground water before DO readings were taken near the
bottom of each piezometer with an Orion Model 820 oxygen meter.
Groundwater dissolved oxygen content of 1.5 mg/ L was found by
Austin (1997) to be a conservative threshold for anaerobiosis in
selected Willamette Valley soils and was used as a threshold value for
analysis.
Temperature
Ambient air and soil temperature readings were taken with a
Digi-Sense Model 8528-40 digital thermometer.
Soil Solution pH
Soil solution pH was measured periodically in the soil water of
the piezometers. A Sper Scientific Model 850001 pH analyzer was
used for the measurements. The average pH for the two wet seasons
at the 75 cm, 35 cm, and 20 cm depths were (a) 5.19, 5.54, 5.73 for
Site 1; (b) 6.0, 5.88, 5.82 for Site 2; and (c) 5.51, 5.59, 5.71 for Site 3.
The average pH for the two wet seasons at the 100 cm, 50 cm, and 25
cm depths at Site 4 were 7.09, 6.03, and 5.82.
Results and Discussion
Data on saturation, anaerobiosis, reduction-oxidation potentials,
and soil temperature will be evaluated to determine if the soils of each
site along the study transect are hydric. Characteristics of soils at
56
each site and trends within each soil profile are discussed.
Comparison of data will be made to determine the differences or
similarities between the sites and the overall trend within the study
area. Both years of the study (9/95 - 9/97) had wetter-than-normal
water seasons which run from October 1st to September 30th. Rainfall
was 158.45 cm and 161.49 cm for the first and second water year,
respectfully, compared to a normal precipitation of 109.22 cm.
Site 1
Saturation
Piezometer and rainfall data are presented in Figure 3.2. No
initial response to precipitation was noted in the first field season until
the second week of December, at which time free water was recorded
in the well and at all three piezometer depths. A 9.5 cm rain event
brought the total seasonal precipitation to 44.6 cm. Water was first
noted in the second field season the first week of December with a 7.8
cm rain event and a seasonal total precipitation of 46.9 cm. Again,
free water was recorded in the well and at all three piezometer depths.
Most saturation lasted less than a week with a few episodes of oneweek duration.
Free water, when observed, occurred at every depth with the
exception of three episodes. The saturation data indicate several
trends: (1) after initial soil moisture recovery of at least 44 cm of
precipitation, the soils were saturated to some degree from rain events
greater than 7 cm the first field season and 5.7 cm the second field
season; (2) once field capacity was reached, there was very little lag
time between these precipitation events and water table response; (3)
episodes of saturation were one week or less.
Figure 3.2.
Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Site 1.
0
9
rag
-20
-3
0
c.)
co
AA
A-
=
-60
co
-80
'CD
El
_cp -100
*21.74 cm
Co
a)
_c
U)
-4
a)
Lei
ON
D
FF1
M AM JON D
J
F M
AM
1995 - 1997
well
D
75 cm
v
35cm
o
20 cm
ppt
J
58
An estimated mean water table at Site 1 for the very short
periods of saturation would be 14.9 cm below the soil surface for the
first field season and 16.4 cm for the second field season.
Anaerobiosis and Iron Reduction
Reduction-oxidation potentials (Eh) are presented in Figure 3.3.
The onset of anaerobic conditions, as indicated by potentials below
+350 mV, occurred for only one period that lasted between one and
two weeks at 30 cm and 50 cm beneath the soil surface. The
potentials never dropped below the +200 mV threshold for iron
reduction. The high Eh values indicate the soils are well aerated the
entire wet seasons.
Site Summary
The soils at this site were not continuously saturated nor had
anaerobiosis for any periods of 14 days or longer within the upper 30.
Therefore, the soils do not meet the hydric soil definition.
Site 2
Saturation
Piezometer and rainfall data are presented in Figure 3.4. Initial
response to precipitation in the first field season was observed in the
100 cm well at the end of October. Water was observed at the 75 cm
depth the second week of November and at the 35 cm and 20 cm
depths two weeks later. The piezorneter data indicate that the soil was
saturated continuously within the upper 20 cm from the last week of
November to the last week of March and between 20 cm and 30 cm
Figure 3.3. Electrode potentials (top) at 10 cm, 30 cm, and 50 cm depths and
duration of saturation as measured by piezometers (bottom) at Site 1.
700
600500400Cl)
300
> 200
g 100
w
Duration of Saturation
20 cm an
35 cm
75 cm
sommm
1111101 NM IN
ammo
moilmo
ONDJFM AM1995JOND
JFM
AMJ
1997
Figure 3.4.
0
U
co
Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Site 2.
0
-20
-40
co
o -60
O
E
-80
..r) -100
X
16
*21.74 cm
12
a)
8
U)
o_
4
ONDJFM AM JOND
1995-1997
1171111111f
well
75 cm
35cm
J
FMniAMJ
20 cm
0
ppt
O
61
until through the first week of April. The water table fluctuated
between 8 cm and 46.5 cm below the soil surface from April to June.
In the second field season, initial water was observed the third
week of November at all piezometric depths due to a high intensity rain
event. The soil was saturated continuously within the upper 20 cm
until the end of March, between 20 cm and 30 cm through the end of
April, and between 30 and 75 cm through the second week of May.
One of the triplicate 75 cm piezometers gave erratic readings
that were not consistent with the other two piezometers. Figure 3.4
shows the average water table from all three 75 cm piezometer data,
but when the data from the third possibly errant piezometer are
graphed separately (Fig. 3.5) this piezometer shows a different
pressure head than indicated by the other two 75 cm piezometers.
This piezometer contained water for only six weeks during the first
field season. The second field season the piezometer consistently had
water but indicated that the water table was 40 cm to 60 cm beneath
the level indicated by the other two 75 cm piezometers.
There are a few possible explanations for the data from the 75
cm piezometers. It is assumed that the first and second 75 cm
piezometers are above the clay or not far enough into the clay to have
an effect on their hydraulic head, since the 2Bt1 clay horizon starts at
70 cm beneath the soil surface at this site. The third 75 cm
piezometer could have become completely clogged in the first field
season and partially unclogged in the second field season when water
was observed but with a lower hydraulic head.
A second possibility is that this piezometer is further into the
clay horizon and is picking up a different pressure potential. The
pressure head at an average of 66.2 cm could be from loss of pressure
due to frictional resistance to movement of water in the clays.
Dissipation of kinetic energy due to friction against pore walls and
Figure 3.5. Water table data (top) below the soil surface with the errant 75 cm
piezometer graphed separately at Site 2.
0
E
C.)
\t4Mk
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ppt
63
pore throats (viscous forces) can be significant when discharge is large.
The different pressure head could be indicating the pressure head of
the rising regional groundwater table. However, these conclusions do
not account for the lack of water in the first field season.
A third plausible assumption is the presence of some type of
macrovoid. In the first field season, the macrovoid could have
appeared and drained the piezometer. Before the next wet season
began, maintenance was done at the sites. All the piezometers were
resealed with bentonite to the soil surface. It was noted that some of
the deeper piezometers took large amounts of bentonite, presumably
because of large cracks that formed in the high shrink-swell clays
below 70 cm.
The water levels indicated by the 20 cm and 30 cm piezometers,
the first and second 75 cm piezometers, and the well are believed to be
from episaturation caused by a perched water table that is occurring
above the clay horizons. Further discussion and evidence of
episaturation is found in the analysis of Site 3 and Plots B and C data.
The mean water table was calculated using the head from the 20
cm and 35 cm piezometers. The mean water table for the first field
season was 12.5 cm below the soil surface from 11/28/95 to 5/30/96.
The mean water table for the second field season was 12.7 below the
soil surface from 11/21/96 to 5/03/97.
Anaerobiosis and Iron Reduction
Reduction-oxidation potentials (Eh) are presented in Figure 3.6.
Conditions fluctuated between aerobic and anaerobic conditions, as
indicated by potentials above and below +350 mV, at all depths the
first month of the wet season. The onset of extended anaerobiosis
began the first week of December at all three depths the first field
Figure 3.6. Electrode potentials (top) at 10 cm, 30 cm, and 50 cm depths and
duration of saturation as measured by piezometers (bottom) at Site 2.
700
600500400U)
300
> 200
100
Duration of Saturation
--
20 cm
35 cm
75 cm
L _tZ
NMI
,k11111111116111111111
_111111111111111111111111 11111111111 11111111111111 I 1111111111111 I 111111
OND J FM AM JOND JFM AMJ
1995-1997
Eh 10 cm
Eh 30 cm
Eh 50 cm
65
season. In the second field season, anaerobiosis again began the first
week of December at the 30 and 50 cm depths and the third week of
December at 10 cm. Water levels fluctuated between the soil surface
and 16 cm causing the delayed anaerobiosis at the 10 cm depth.
Iron reduction, as indicated by potentials below 200 mV, did not
occur for any significant period at 10 cm below the soil surface.
However, anaerobiosis occurred at 10 cm from 12/05/95 to 4/25/96
the first field season and from 12/24/96 to 6/01/97 in the second
field season. Iron reduction at 30 cm below the soil surface occurred
mainly from 12/19/95 to 5/30/96 in the first field season and from
12/19/96 to 5/16/97 in the second field season. Reducing conditions
at 50 cm generally occurred earlier, lasted longer, and had lower Eh
values than at 30 cm. Reduction at 50 cm occurred from 12/12/95 to
6/14/96 in the first field season and from 12/10/96 to 5/16/97 in
the second field season.
The dissolved oxygen (DO) values (Fig. 3.7) show some trends
but do not correlate well with redox potentials. Gradual depletion of
DO from the system in late fall with increased precipitation was
observed as expected. Although the Eh data indicate that the soils
were anaerobic and iron reduction was occurring, the data show the
DO levels were seldom below the 1.5 mg/L value found in other
anaerobic Willamette Valley soils (Austin, 1997). However, Cogger and
Kennedy (1992) found that soils with DO levels less than 5 mg/L for
greater than 80% of the time in the wet season had low redox
potentials in Puget Lowland soils of western Washington. The average
dissolved oxygen (DO) values were: 3.9 mg/L at the 20 cm depth, 2.3
mg/L at the 35 cm depth, 4.6 mg/L at the 75 cm depth, and 3.4 mg/L
in the 100 cm well.
Some of the DO data from 75 cm may seem to contradict
conditions inferred from the Eh data The highest DO values occurred
Figure 3.7. Groundwater dissolved oxygen values (bottom) from piezometric
water and electrode potentials (top) at Site 2.
700600500-
4003O0
.7)
.? 200
rg
100
-12
-10
,
0
fi
.
-ss",
. ,......,
,:.
. .........
1
P.
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ra ;a
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61
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.
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ONDJ FM AM JOND J FM AMJ
1995 -1997
Eh 10 cm
0
Eh 30 cm
Eh 50 cm
DO 20 cm --v-- DO 35 cm
DO 75 cm
67
mostly at the 75 cm depth, which might be expected because both
organic matter and microbial activity decrease with depth. But redox
potentials indicate that reduction was more intense with depth at Site
2, which is partly attributed to sufficient levels of organic matter
content (1.2%) However, it must be noted that Eh measurements are
taken at 50 cm versus 75 cm for the DO values.
.
In addition, higher than expected values of dissolved oxygen at
all measured depths are believed to be attributed to 02 introduced into
the piezometers when the DO readings were taken. It is surmised that
the recharged water in the piezometers was not deep enough in most
cases to offset the diffusion of air from the air-water interface and that
02 was introduced as the probe was moved up and down.
Saturation and Eh
The duration of saturation data and Eh data (Fig. 3.6) indicate
there was a one to two-week initial lag period between saturation and
reducing conditions. The onset of extended anaerobic conditions
occurred within one week of saturation at all three depths in the first
field season and within two weeks of saturation at 30 cm and 50 cm
and within five weeks at 10 cm in the second field season. In the
spring, Eh values at 30 cm and 50 cm were not significantly affected
by brief periods of unsaturated conditions, as were the Eh values at 10
cm. The low response is attributed to a biological activity flush as
temperatures rose. Consumption of 02 and production of CO2 by
microbes would exceed diffusion rates of 02 into the soils and diffusion
of CO2 out of the soils at deeper depths. It is also plausible that the
low response may indicate that the macropores are drained but the
micropores are not.
68
Soil Temperature
Soil temperature (Fig. 3.8) remained above 5°C except on two
occasions during the first field season. The first drop below 5°C was in
December at the 10 cm depth. The second drop occurred at the 10 cm
and 30 cm depths in February. Neither occurred during the
recognized growing season for the valley. No drops occurred below 5°C
at 50 cm below the soil surface.
Eh values and soil temperatures (Fig. 3.9) of the saturated soils
were well correlated at some times and were not well correlated at
others. In general, the initial seasonal decrease in soil temperature
had no effect on Eh values. Eh values continued to decrease with the
onset of saturation in the early winter. In mid winter and late winter,
decreases in temperature correlated with slight increases in Eh values
at 10 cm but had no effect on the Eh values at 30 cm beneath the soil
surface. The increase in soil temperatures in spring increased
biological activity, causing the Eh values to decrease at the 30 cm and
50 cm depths.
Site Summary
The soils of this site exceeded the thresholds for continuous
saturation with anaerobic conditions in the upper 30 cm during the
portion of the year when soil temperatures are above 5°C (41°F) at 50
cm and meet the hydric soil definition. Continuous saturation
occurred for an average of 19.5 weeks and anaerobic conditions for an
average of 26 weeks.
Figure 3.8. Soil temperature data at 10 cm, 30 cm, and 50 cm depths at Site 2.
-5
0ND
J
F M AM
J ON D
J FM A M
1995- 1997
Temp 10 cm
v
Temp 30 cm
L Temp 50 cm
Figure 3.9. Soil temperature data (bottom) and electrode potentials (top) at Site 2.
700
600500
400
1 300
0
.? 200-
a)
co
E 100
.c
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o
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go 8og0
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0
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5
0
1995-1997
Eh 10 cm
Temp 10 cm
v
Eh 30 cm
Eh 50 cm
Temp 30 cm
Temp 50 cm
0 -1
71
Site 3
Saturation
Piezometer and rainfall data are presented in Figure 3.10. Initial
response to precipitation in the first field season was observed the
second week of November in the 100 cm well. One week later the
water table was observed in the 75 cm piezometers and within two
weeks in the 35 cm and 20 cm piezometers. Like the soils at Site 2,
water appeared at all measured depths the third week of November
due to a high intensity rainfall event in the second field season.
The piezometer data indicate two pressure potentials. The 20
cm and 35 cm piezometer data have a pressure head that is believed to
indicate episaturation above the 2Bt clay horizon that starts at 42 cm
beneath the soil surface. The well data (free water) correspond with
the level of water indicated by the 20 cm and 35 cm piezometer
pressure head potentials, which suggests that the piezometric data are
giving true estimates of the piezometric surface.
The 75 cm piezometer data that have a different pressure
potential from the 20 and 30 cm piezometers could be indicating loss
of pressure due to frictional resistance to movement of water in the
clays as discussed for Site 2 or the pressure head of a regional ground
water table. The piezometers would be located approximately 33 cm
into the slowly permeable gray clay 2Bt horizon. Since all three 75 cm
piezometers are showing lower pressure heads, it is unlikely that the
piezometers are giving erratic readings or that macrovoids are draining
the piezometers (which is believed to be occurring at Site 2).
Water was noted one week earlier at 75 cm than at 20 and 35
cm the first field season. The data could indicate either a rising
regional ground water table or localized vertical flow down shrinkage
cracks. Subsurface bypass or pipeflow (turbulent flow) can give lower
Figure 3.10. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Site 3.
°
-20
C-)
co
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-60
-80
*21.74 cm
-4
FM AM JOND
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1995-1997
well
75 cm
35cm
0
FM AM
20 cm
ppt
0
73
horizons a rapid response to rainfall (Atkinson, 1978; Whipkey and
Kirkby, 1978). As noted in Chapter 2 and shown in Tables 2.2 and
2.3, the 2Bt gray clay horizon had very high COLE values (>0.09),
LEP/clay ratio (>0.15) that indicates smectitic mineralogy, and
pressure faces. All these characteristics indicate high shrink-swell
clays. However, the surface horizons of soils at Sites 2 and 3 indicate
only moderate (COLE values 0.03 to 0.06) shrink-swell ability while
the subsurface horizons above the 2Bt clay horizon have a low (COLE
values <0.03) shrink-swell class. Examination of the soil profile in
July and again in September showed no evidence of large channels.
The soil was saturated continuously within the upper 20 cm
until the third week of March and between 20 cm and 30 cm through
the first week of April in the first field season. The water table
responded to the seasonal decrease in precipitation with episodic
saturation from April through May. In the second field season, the soil
was continuously saturated within the upper 20 cm until the end of
March and between 20 cm and 30 cm to the first week of May. The
second pressure head indicates water was at 75 cm from the initial
response to the end of May in the first field season and from initial
response to the third week of May in the second field season.
The mean perched water table for both field seasons was 9.7 cm
below the soil surface from 11/28/95 to 5/24/96 and 9.8 cm from
11/21/96 to 5/03/97. The mean for the second pressure head was
53.4 cm below the soil surface from 11/21/95 to 5/30/96 and 53.4
cm from 11/21/96 to 5/10/97.
Anaerobiosis and Iron Reduction
Reduction-oxidation potentials (Eh) are presented in Figure
3.11. Conditions fluctuated between aerobic and anaerobic conditions,
as indicated by potentials above and below +350 mV, at all depths the
Figure 3.11. Electrode potentials (top) at 10 cm, 30 cm, and 50 cm depths and
duration of saturation as measured by piezometers (bottom) at Site 3.
700
600
500
400
17; 300
3) 200
100
Duration of Saturation
20 cm
35 cm
75 cm
JIII
ONDJ FM AM JOND J FM AMJ
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
1995 1997
I
I
I
I
I
I
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1
I
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75
first month of the wet season. The onset of extended anaerobiosis
began the third week of November at all three depths the first field
season. In the second field season, anaerobiosis again began the third
week of November at 50 cm and the last week of November at the 10
and 30 cm depths.
The Eh values indicate a different reducing environment than
exists in the soil at Site 2, particularly at the 10 cm and 50 cm depths.
Redox potentials were much lower and iron reduction continuous at
the 10 cm depth but potentials were higher at the 50 cm, which is the
reverse of reduction in the soils of Site 2. Differences in Eh values and
reducing conditions between the soils of Site 3 and the soils of Site 2
at the 10 cm and 50 cm depths are attributed to two factors. Site 3
soils at 10 cm have longer reduction periods and more intense
reducing conditions (lower Eh) due to a higher mean seasonal water
table (9.8 cm versus 12.6 cm). Site 2 soils at 50 cm have longer
reduction periods and more reduced conditions due to higher organic
matter content (1.2% versus 0.7%).
Overall, reducing conditions at Site 3 were less intense in the
second field season than in the first. Iron reduction at 10 cm below
the soil surface occurred mainly from 11/28/95 to 5/24/96 in the
first field season and mainly from 12/05/96 to 5/03/97 in the second
field season. Reduction at 30 cm beneath the soil surface occurred
from 12/05/95 to 5/30/96 in the first field season and from
11/27/96 to 5/16/97 in the second field season. Reduction at 50 cm
occurred from 12/05/95 to 5/30/96 in the first field season and from
12/05/96 to 5/16/97 in the second field season.
The average dissolved oxygen (DO) values (Fig. 3.12) at the 20
cm and 35 cm depths was 2.4 mg/L for the two wet seasons. The
average DO value in the 75 cm piezometer was 6.9 mg/L and the
average DO in the 100 cm well was 3.4 mg/L. The DO values were
Figure 3.12. Groundwater dissolved oxygen values (bottom) from piezometric
water and electrode potentials (top) at Site 3.
3
E
700
600
500
400
300
200
100
12
10
w
rs
11 I
ez r:s
r -, " " zi"
113
ar s
V
IQ
-8
r.4
t.-T,
IQ
IQ
6
4
-2
_JI11111111111111111111111111111111111111111111111111111111111111111111 LO
OND
FM AM JOND JFM AMJ
1995 -1997
Eh 10 cm
Eh 30 cm
e DO 20 cm
DO 35 cm
Eh 50 cm
0
DO 75 cm
77
lower at the 20 cm depth compared to the Site 2 values due to higher
water columns in the piezometers. The higher DO values at the 75 cm
depth compared to Site 2 values were due partly to lower levels of
microbial activity as confirmed by the higher redox potentials at 50
cm. The higher values also were due partly to the diffusion of oxygen
from the air-water interface in the piezometers as discussed in the
section on soils of Site 2.
Saturation and Eh
The duration of saturation data and Eh data (Fig. 3.11) indicate
the onset of anaerobic conditions occurred one week prior to
continuous saturation at all three depths in the first field season. The
loss of dissolved oxygen was probably due to a combined heavy rain
event and microbial flush. Onset of anaerobic conditions occurred
within one week of saturation at all three depths during the second
field season. Brief periods of unsaturated conditions in the spring did
not significantly affect Eh values at 30 cm but had a slightly greater
effect on the Eh values at the 10 cm depth. The low responses, like
those at Site 2, are attributed to biological activity flush as
temperatures rise.
Soil temperature
Soil temperatures (Fig. 3.13) in the first field season paralleled
the soil temperatures at Site 2 except the two episodes below 5°C were
a few degrees lower than at Site 2. The second field season
temperature data show a drop below 5°C in December and again in
January at the 10 cm depth. The temperature did not drop below 5°C
at 50 cm.
Figure 3.13. Soil temperature data at 10 cm, 30 cm, and 50 cm depths at Site 3.
30
0
o
p MZ
-- e
Alb
v Ell
kV/
1111
mmum
41,m
V
cp
0
V
0
0
ONDJ FM AM JOND J FM AM
1995
- 1997
0 Temp 10 cm
Temp 30 cm
o Temp 50 cm
79
Soil temperatures and Eh values (Fig. 3.14) of the saturated
soils were not well correlated. Like the soils of Site 2, the initial
seasonal decrease in soil temperature had no effect on Eh values, and
Eh values continued to decrease with the onset of saturation in the
early winter. In mid winter and late winter, some drops in
temperature were associated with very slight increases in Eh at all
depths and other drops seemed to be unrelated to Eh. The increase in
soil temperatures in early spring increased biological activity and
affected Eh values to varying degrees. The 10 cm Eh values decreased
the most, the 30 cm Eh values were slightly affected, and the 50 cm
Eh values showed no response.
Site Summary
The soils of this site exceeded the thresholds for continuous
saturation with anaerobic conditions in the upper 30 cm during the
portion of the year when soil temperatures are above 5°C (41°F) at 50
cm and meet the hydric soil definition. Continuous saturation
occurred for an average of 21.5 weeks and anaerobic conditions for an
average of 26 weeks.
Site 4
Saturation
Piezotneter and rainfall data are presented in Figure 3.15. Initial
response to precipitation in the first field season was observed the
second week of November in the 100 cm well and the 50 cm
piezometer. Two weeks later water was observed in the 25 cm
piezometer and the 100 cm piezometers. The second field season had
a similar pattern of wetting as the first. Water was first observed in
Figure 3.14. Soil temperature data (bottom) and electrode potentials (top) at Site 3.
700
600
500
400
3 300
0
.? 200
a)
5
100
-20
0 mm
w
15
S%®
00
rn
a)
0
Mm
° rR" RiOw EM*
o
t1
op
O
2
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10
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5
0
ONDJ FM AM JOND
1995-1997
Eh 10 cm
0
Temp 10 cm
"
J
FM AMJ
Eh 30 cm
Eh 50 cm
Temp 30 cm
Temp 50 cm
00
Figure 3.15. Precipitation data (bottom) and water table data (top) below the soil
surfaceas observed in a well at 100 cm and piezometers at 100 cm, 50
cm, and 25 cm depths at Site 4.
0
,
Era = =
a)
ots
.21),
-20
C.)
-40
o
-60
co
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0
_a -100
X
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1995-1997
well
o
100 cm v 50 cm
o
FM AM
25 cm
ppt
82
the 100 cm well and the 50 cm piezorneter the second week of
November; one week later in the 25 cm; and in the 100 cm piezometer
the last week of November.
The hydrology of this soil is different than at the other sites.
Water in the 100 cm well indicated that saturated conditions existed
somewhere within 100 cm of the soil surface. However, the wetting
pattern was not from the bottom up from a rising water table as
evidenced by the lack of water in the 100 cm piezometer when the 50
cm piezometer had water. Saturation was not occurring from the
surface down as evidenced by lack of water in the 25 cm piezometer.
The data suggest the initial wetting of this soil occurred from 50 cm
upward.
Two physical soil factors could account for this pattern of
wetting. Soil physical characteristic data from Chapter 2 (Table 2.3)
showed the Bt clay horizon between 51cm and 90 cm had a slightly
lower fine clay to total clay ratio and a lower COLE index than the
overlying clay horizons, which would imply a discontinuity. The lower
COLE index (0.075) compared to the overlying horizon (0.105)
indicates this horizon has less shrink-swell capacity, therefore, less
propensity toward cracking. These two factors, along with the
piezometer data, suggest that rain water could be flowing down along
ped faces and macro cracks (bypass flow or pipeflow) formed by the
drying of the shrink-swell soils during the summer months. The water
slows and forms a perched water table at the Bt horizon as indicated
by water in the 50 cm piezometer when no water is in the 100 cm
piezometer.
Like Site 2, one of the triplicate 75 cm piezometers gave erratic
readings that were not consistent with the other two piezometers.
Compared to Fig. 3.15 where all three 75 cm piezometer data are
83
averaged, the errant piezometer data are graphed separately in Fig.
3.16. Pressure heads from the other two 75 cm piezometers
correspond to the pressure heads given by the 25 cm and 50 cm
piezometers. Water appeared in the divergent (#1) piezometer at least
two weeks later than the other two piezometers in both field seasons.
In addition, this piezometer indicated a large difference in average
pressure potentials for the two field seasons, 57.8 cm in the first field
season compared to 38.3 cm in the second field season. This
divergent piezometer may be positioned in a macrovoid of some type
that affects the hydraulic head, or the piezometer may be partially
clogged.
The data from the 25 cm, 50 cm, and two of the 75 cm
piezometers, along with the well data, suggest that the pattern of
wetting occurred both upward and downward from a perched water
table at 50 cm below the soil surface. Within two weeks, either the
wetting front had reached the 100 cm depth or the ground water had
risen to meet the perched water table.
Continuous saturation was observed within the upper 30 cm
from the last week of November through the first week of May in the
first field season and from the third week of November through the
first week of May in the second field season. The mean water table for
both field seasons was 5.5 cm below the soil surface from 11/28/95 to
5/30/96 and 5.5 cm from 11/27/96 to 6/01/97.
Anaerobiosis and Iron Reduction
Reduction-oxidation potentials (Eh) are presented in Figure
3.17. The onset of anaerobic conditions began the second week of
November at the 50 and 100 cm depths and the third week of
November at 25 cm in the second field season. Reducing conditions
differed in the soils of this site compared to the soils at the other sites.
Figure 3.16. Water table data (top) below the soil surface with the errant 75 cm
piezometer graphed separately at Site 4.
0
"Sligreit.:AA,
E
9-a)
r
NV
-20
p.
ra
tcu
0
3
0
-40
112
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-Q -100
`21.74 cm
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a)
a)
T
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0
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NDJFM AMJONDJFM
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1995 1997
well
100 cm
50 cm
25 cm
1
II
IT III
ppt
MJ
Figure 3.17. Electrode potentials (top) at 25 cm, 50 cm, and 100 cm depths and
duration of saturation as measured by piezometers (bottom) at Site 4.
700
600
500
400
IT') 300
3) 200
100
w
Duration of Saturation
25cm
50cm
100 cm
ONDJ FM AM JOND J FM AMJ
1995-1997
Eh 25 cm
Eh 50 cm
Eh 100 cm
86
The overall Eh values at the 25 cm depth indicate stronger (lower Eh)
reducing conditions at this depth than exist in the other soils.
Iron reduction occurred concurrently with anaerobiosis at 25
cm, within one week at 50 cm, and within three weeks at 100 cm in
the first field season. Reduction occurred at 25 cm from 11/14/95 to
6/14/96; at 50 cm from 11/21/95 to 5/30/96; and at 100 cm from
12/19/95 to 5/30/96. Reduction in the second field season occurred
at 25 cm from 11/27/96 to 6/1/97; at 50 cm from 12/05/96 to
6/01/97; and at 100 cm from 3/22/97 to 6/1/97.
The dissolved oxygen (DO) values (Fig. 3.18) were very erratic
and difficult to correlate with Eh values in the first field season.
However, a pattern emerged in the second field season. Average DO
values of 1.8 mg/L at the 25 cm and 50 cm depths correlated well with
the Eh data. The average DO value for the 100 cm piezometer was 5.0
mg/L while the average value for the 100 cm well was 3.0 mg/L.
Saturation and Eh
The duration of saturation data (Fig. 3.17) indicate there was no
initial lag period between saturation and reducing conditions for either
field season. Anaerobic conditions occurred concurrently with
saturation at all three depths the first field season. In the second field
season, anaerobiosis occurred one week before saturation at the 50
and 100 cm depths and concurrently with saturation at 25 cm. Once
saturated, the soils were continuously saturated and reduced at the
25 and 50 cm depths except for a brief episode at the 25 cm depth.
Soil temperature
Soil temperatures (Fig. 3.19) remained above 5°C except for one
occasion at the 25 cm depth in February of the first field season and
Figure 3.18. Groundwater dissolved oxygen values (bottom) from piezometric
water and electrode potentials (top) at Site 4.
OND
J
F M AM JOND
FM
1995 -1997
Eh 25 cm
Eh 35 cm
Eh 100 cm
DO 25 cm v DO 50 cm
DO 100 cm
AM
J
Figure 3.19. Soil temperature data at 25 cm, 50 cm, and 100 cm depths at Site 4.
30
^25
0
220 20
rn
a)
o 0
v9v
13-1510
a)
E
5
a)
u)
0
0
_5
OND J FM AM JOND
J
FM
AM
1995-1997
0 Temp 25 cm
v
Temp 50 cm
o Temp 100 cm
89
one occasion at the 25 cm depth in December during the second field
season.
Correlation between soil temperatures and Eh values (Fig. 3.20)
of the saturated soils shows that the initial seasonal decrease in soil
temperature had an effect on the rate and intensity of the onset of
reducing conditions. Slightly higher soil temperatures in the first field
season led to a sharper decline in Eh values and a more intense
reducing environment than in the second field season. In mid-winter
and late winter, major drops in temperature caused very slight
increases in Eh at all depths. Increase in soil temperatures in early
spring increased biological activity and affected Eh values differently in
the two field seasons. Eh values in the first field season show little
response to the increase in soil temperatures. The Eh values in the
second field season showed a distinct inverse relationship, with Eh
values decreasing as soil temperatures increased at all measured
depths.
Site Summary
The soils of this site exceeded the thresholds for continuous
saturation with anaerobic conditions in the upper 30 cm during the
portion of the year when soil temperatures are above 5°C (41°F) at 50
cm and meet the hydric soil definition. Continuous saturation
occurred for an average of 24 weeks and anaerobic conditions for an
average of 29 weeks.
Plots A - F
Additional data on the hillslope hydrology were provided by
piezometers spaced between the four main sites. These data are
presented in Figures 3.21 through 3.26.
Figure 3.20. Soil temperature data (bottom) and electrode potentials (top) at Site 4.
700
600
500400
3 300200100
_c
'Mn
Npo,
vGimme
0.0.00y
0
73av°,7
0
_
.MI;49[imm
0
0
ONDJ FM A M
I
I
I
I
I
I
I
I
I
I
I
-20
-15
-10
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
JON D
Eh 50 cm
Temp 25 cm
Temp 50 cm
I
J
1995-1997
Eh 25 cm
-5
0
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
FM A M
Eh 100 cm
°
I
Temp 100 cm
I
I
I
J
I -0
0
91
Saturation
Plot A (located 24.5 m upslope from Site 1) piezometric data (Fig.
3.21) show very similar hydrology as Site 1. The soils are somewhat
dryer than Site 1 soils as indicated by the lack of free water at any
time in the 20 cm piezometer. Saturation within the upper 30 cm
occurred for episodes that lasted less than two weeks.
Plot B (located 6.3 m downslope from Site 1) piezometric data
(Fig. 3.22) show a strong contrast from Site 1 data. Saturation occurs
high in the profile for extended periods. Water was observed in the 75
cm piezometer from the last week in November through the third week
of March in the first field season and from the third week in November
to the first week of April in the second field season. The soil was
saturated continuously within the upper 30 cm for two weeks (from
the first week of December to the third week of December) and for five
weeks (from the first week of January to the second week of February)
in the first field season. During the second field season, the soil
within the upper 30 cm was saturated continuously for four different
episodes that lasted two to four weeks. The average water table was
16.8 cm beneath the soil surface from 11/28/95 to 3/8/96 and 19.1
cm from 11/21/96 to 3/22/97.
The water table observed at Plot B could be indicative of
episaturation caused by water perching over the restrictive clay
horizons that start at approximately 72 cm below the soil surface at
this site. The well data cannot be used to indicate rising water from
the 100 cm depth since open construction would allow water to drain
into the well at the restrictive boundary. Water initially occurred in
the 35 cm and 75 cm on the same date, which indicates that water
levels are being influenced by the slowly permeable gray clay horizon.
Perching water would account for the significant change in hydrology
over a short 6.3 m distance between Site 1 and Plot B.
Figure 3.21. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Plot A.
g
V
0
-20
`t
-40
=
-60
cp
0
-80
T
s) -100
-16
*21.74 cm
V
-12
co
a)
_c
7-3
-8
ED_
co
a)
Q.
0N
F
D
M
Ar
M
JON D
FM A M
1995 1997
well
a
75 cm
35cm
20 cm
ppt
Figure 3.22. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Plot B.
0
-20
`t
-40
=0
-60
(1
-80
16
><
_ca -100
*21.74 cm
as
12
a)
_a
-8
ED_
U)
-4
a)
ON D
FM
AM
JON
D
1995 - 1997
well
C3
75 cm
35cm
o
J
FM AMJ
20 cm
ppt
0
94
Plot C (located 5.3 m downslope from Plot B and 5.8 m upslope
from Site 2) piezometric data (Fig. 3.23) are very similar to Site 2 data
but with shorter duration of saturation. Continuous saturation was
observed within the upper 30 cm from the last week of November to
the third week of March in the first field season and from the third
week of November through the third week of March in the second field
season. The water table is believed to be indicative of episaturation,
like that of Plot B. The 2Bt clay horizon of this plot starts at
approximately 81 cm below the soil surface. The average water table
was 12.2 cm beneath the soil surface from 11/28/95 to 5/24/96 and
14.6 cm from 11/21/96 to 5/03/97.
Plot D (located 11 m downslope from Site 2) piezometric
data (Fig. 3.24) are very similar to Site 3 data. The piezometric data
indicate two pressure heads. Water was first observed in the 75 cm
piezometer the second week of November and at the 35 cm and 20 cm
piezometers two weeks later. The 2Bt clay horizon started at
approximately 42 cm beneath the soil surface at this plot creating
episaturation higher in the soil profile than at Plots B and C. This 75
cm piezometer embedded over 30 cm into the clay horizons could, like
the 75 cm piezometers of Site 3, be indicating loss of pressure due to
frictional resistance to movement of water in the clays or the pressure
head of a rising groundwater table.
The soil was saturated continuously within the upper 30 cm
from the last week of November to the first week of April in the first
field season and from the third week of November to the first week of
May in the second field season. The average perched water table was
7.8 cm below the soil surface from 11/28/95 to 5/24/96 and 9.1 cm
from 11/21/96 through 5/03/97. This second pressure head was
59.1cm and 67.3 cm beneath the soil surface in the first and second
field season, respectively.
Figure 3.23. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Plot C.
°
-20
c.)
-60
U)
-80
0
.o -100
*21.74 cm
ci
ON
D
liiiii
J FM AM
J ON D
1995 - 1997
well
75 cm
35cm
0
FM AM
11
J
20 cm
ppt
Figure 3.24. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Plot D.
0
t
-20
C.)
-40
co
o -60
-80
*21.74 cm
ON
D
J
r-ir'1-'111Irl--lir-'1--F M AM J ON
D J F M A M rJ
1995 1997
well
75 cm
35cm
o
20 cm
ppt
97
Plot E (located 9.7 m downslope from Plot D and 10.2 m upslope
from Site 3) piezometric data (Fig. 3.25) also were very similar to Site 3
data except for lack of a second pressure head. The 2Bt clay horizon
started at approximately 61 cm beneath the soil surface at this plot.
Given soil variability, the clay horizons may start well below 61 cm,
and the 75 cm piezometer may not be far enough into the clay to affect
the hydraulic head. The soil was saturated continuously within the
upper 30 cm from the last week of November to the first week of April
in the first field season and from the third week of November to the
first week of April in the second field season. The average water table
was 8.1 cm beneath the soil surface from 11/28/95 to 5/24/96 in the
first field season and 9.2 cm from 11/21/96 to 5/03/97 in the second
field season.
Plot F (located 3.2 meters downslope from Site 3 and 36 meters
upslope from Site 4) piezometric data (Fig. 3.26) indicate hydrology
similar to that of Plot E and Site 3. Like Plot E data, there was no
indication of a second pressure head. The 2Bt clay horizon began at
72 cm, which indicates the 75 cm piezometer has the pressure head of
the perched water table as does the 35 cm and 20 cm piezometers.
Continuous saturation occurred within the upper 30 cm from the last
week of November through the first week of March in the first field
season and from the third week of November to the end of March in
the second field season. The average water table was 14.3 cm beneath
the soil surface from 11/28/95 to 5/24/96 in the first field season
and 13.9 cm from 11/21/95 to 5/03/97 in the second field season.
The higher average water table at Plot E (14.1 cm) compared to
Site 3 (9.7 cm) is to due anthropogenic disturbance. An elevated
gravel road was constructed with fill between Site 3 and Plot F. Water
from subsurface lateral flow from upslope is impeded by the
Figure 3.25. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Plot E.
C)
U
-20
-40
co
= -60
U)
0
-80
16 R.
..c) -100
12
CO
as
a)
8
4
0
0N
D
M
AM
0
JON D
1995 1997
75 cm
35cm
0
20 cm
ppt
Figure 3.26. Precipitation data (bottom) and water table data (top) below the soil
surface as observed in a well at 100 cm and piezometers at 75 cm, 35
cm, and 20 cm depths at Plot F.
0
U
a)
-20
t -40
c/9
=0
-60
co
-80
Tv
_o -100
*21.74 cm
CO
a)
a)
co
a)
OND
AM
JFM AMJ
J
1995 - 1997
well
o
75 cm
35cm
o
20 cm
ppt
100
obstruction, breaks out, and becomes surface flow along the lower
section of the road.
Summary for All Sites and Plots
Periods of continuous saturation within the upper 30 cm,
seasonal mean water table levels, onset of anaerobiosis, and periods of
Fe reduction for the four pedons of the study area are summarized in
Table 3.1. Soil temperature as related to growing season is not
considered a factor in determining whether the four sites have hydric
soils, since the soil temperature never went below 5°C at 50 cm
beneath the soil surface.
Continuous saturated conditions were not found at Site 1 but
varied from 19 to 25 weeks at Sites 2, 3, and 4. Duration of
continuous saturation averaged 19.5 weeks at Site 2, 21.5 weeks at
Site 3, and 24 weeks at Site 4. Seasonal mean water tables ranged
from 12.6 cm at Site 2 to 5.5 cm at Site 4.
Anaerobic conditions provided in Table 3.1 occur within 30 cm
of the soil surface. For Sites 3 and 4, this could be synonymous with
"in the upper 30 cm" as the 10 cm data showed the same reducing
environment. Site 2 data at the 10 cm depth showed a different
reducing environment than at 30 cm. Anaerobiosis occurred for four
to five months at the 10 cm depth but iron reduction was sporadic and
very brief. It is assumed that around 13 cm, where the mean seasonal
water table level occurs, the environment is more like the reducing
environment expressed by the 30 cm redox potentials.
Data show the onset of anaerobiosis began anywhere from two
weeks before continuous saturation to two weeks after and continued
for up to ten weeks past the end of continuous saturation. Extensive
periods of iron reduction lagged behind conditions of continuous
Table 3.1. Periods of continuous saturation within the upper 30 cm, seasonal mean
water table levels, and periods of oxygen and iron reduction for the four
pedons of the study area.
Hydrologic Data
Seasonal Mean
Water Table Levels
Site
Continous Saturation
within the Upper 30 cm
Site 1
less than two weeks
Site 2
Site 3
Site 4
Main Periods of Anaerobic Conditions at 25-30 cm
Onset of Anaerobiosis
Iron Reduction
not applicable
one week period
none
11/28/95 4/04/96
11/21/96 4/05/97
12.5 cm
12.7 cm
12/05/95
12/05/96
12/19/95 - 5/30/96
11/28/95 4/04/96
11/21/96 5/03/97
9.7 cm
9.8 cm
11/21/95
11/27/96
12/05/95 5/30/96
11/28/95 - 5/04/96
11/21/96 - 5/10/97
5.5 cm
5.5 cm
11/14/95
11/21/96
12/19/95 5/16/97
11/27/95 - 5/16/97
11/14/95 6/14/96
11/27/96 - 6/01/97
102
saturation for three to four weeks in Site 2 soils, one week in Site 3
soils, and one week or less in Site 4 soils. Duration of anaerobic
conditions ranged from an average of 26 weeks at Site 2, 26 weeks at
Site 3, and 29 weeks at Site 4.
Table 3.2 summarizes the hydrologic data for the six additional
plots (Plots A-F). The additional hydrologic data provided by the
piezometers placed between the four main sites indicate that the
boundary for non-hydric soils and hydric soils is probably between
Site 1 and Plot B or at Plot B. Site 1 soils had a few episodes of
saturation that lasted less than two weeks compared to Plot B soils
that had several episodes that lasted two to five weeks. Plot B had an
average seasonal water table at 17 cm. Perching water could account
for the significant change in hydrology over the short 6.3 m distance
between Site 1 and Plot B. This hydric soil boundary would correlate
with the hillslope morphology, since the two clay layers on the upper
transect were found to taper to an end where a slight break in slope is
evident below Site #1.
Conclusion
The summarized hydrologic and reductive data provide evidence
that the soils of Sites 2, 3, and 4 meet the conditions for "saturated,
flooded, or ponded long enough during the growing season to develop
anaerobic conditions in the upper part" and are hydric soils according
to the hydric soil definition.
The hydrologic data indicate that the initial precipitation in late
fall and early winter replaced soil moisture content lost to dry
summers. Once field capacity was reached through frequent small
rain events or through major high intensity and/or long duration rain
events, further precipitation led to perched water tables and
103
Table 3.2. Periods of continuous saturation within the upper
30 cm and seasonal mean water table levels for
plots between Sites 1-4.
Hydrologic Data
Plots
Continous Saturation
within the Upper 30 cm
Seasonal Mean
Water Table Levels
Plot A
less than 1 week
not applicable
Plot B
12/05/95 - 12/19/95
1/02/96 - 2/09/96
4 episodes at 2-4 weeks (96-97)
16.8
19.1
Plot C
11/28/95 3/23/96
11/21/96 3/22/97
12.2
14.6
Plot D
11/28/95 4/04/96
11/21/96 5/03/97
7.8
9.1
Plot E
11/28/95 4/04/96
11/21/96 - 4/05/97
8.1
9.2
11/28/95 - 3/08/96
11/21/96 - 3/30/97
14.3
13.9
Plot F
104
episaturation. Episaturation occurred at Sites 2 and 3 and Plots B-F
with temporary episaturation occurring at Site 4. Water levels
fluctuated with rain events, but water tables remained fairly stable
and soil stayed saturated high in the soil profiles for a majority of the
wet season (October June).
The reduction-oxidation potentials support the occurrence of
varying reducing environments at Sites 2, 3, and 4. The onset of
anaerobiosis began less than two weeks after continuous saturation at
these sites. Generally, iron reduction occurred between one and four
weeks after continuous saturation began and lasted two to eight weeks
after continuous saturation ended. The onset of significant periods of
iron reduction correlated with average saturation levels. Soils at Site 2
with the lowest mean water table level (12.6 cm) had the longest lag
time between saturation and iron reduction versus Site 4 soils with the
highest mean water table (5.5 cm) where iron reduction occurred
simultaneous with saturation.
In addition, the hydrologic data and redox data correlated with
the morphological properties noted in Chapter 2 for each of the four
pedons. Short episodic saturation events in Site 1 soils that averaged
around 16 cm beneath the soil surface correspond to the occurrence of
fine iron concretions. The mean water table levels for Sites 2 and 3
corresponded to horizons that had at least 30% high value and low
chroma (4/2) matrix colors and many distinct iron masses. Nearsurface saturation in the soils of Site 4 is associated with the presence
of oxidized rhizospheres found at the surface and many distinct iron
masses at 6 cm beneath the soil surface.
105
Chapter 4
FIELD INDICATORS OF HYDRIC SOILS - APPLICATION TO THE
WITHAM HILL BACKSLOPE-FOOTSLOPE STUDY SITE
Introduction
The publication, Field Indicators of Hydric Soils in the United
States (US Department of Agriculture, Natural Resources Conservation
Service, 1996) is designed as a guide to help identify hydric soils in the
field based on soil morphology. The purpose of the indicators is to
provide a field method for identifying soils that meet the hydric soil
definition without the need for further data collection. The indicators
are based on the concept that hydric soils exhibit morphological
evidence of long-term hydrologic and redox conditions. Indicators are
classified according to texture classes and further defined by
geographic location. The indicators were designed to be region specific
to adapt to regional variations in hydric characteristics. A soil in
question can be classified as hydric when one positive hydric soil
indicator is found. However, the lack of an indicator does not exclude
the soil from being hydric.
The availability of field indicators for identification of hydric soils
is a recent development with the first version being drafted and
accepted for use in 1995. The current list is but a beginning; changes
and additions are anticipated as the indicators are field-tested and
more field data are collected. The development of field indicators to
characterize all hydric soils requires understanding of processes and
interactions in soils and the conditions that fuel them. The
Interagency Field Indicator Committee welcomes recommendations
and supporting documentation from anyone involved with research on
wet soils. The committee defines supporting documentation as soil
106
pedon descriptions, water table data, duration of saturation data,
redox potential measurements, a, a' dipyridyl test results, and
vegetative data (US Department of Agriculture, Natural Resources
Conservation Service, 1996).
The purpose of this chapter is to apply the current indicators
(Ver. 3.2, July 1996) to the study site soils. One objective is to
determine if the soils can be considered hydric based on their
morphologies and the morphological requirements of current
indicators. Another goal is to examine and evaluate the indicator's
capability to identify those soils at the study area that met the hydric
soil definition and provide recommendations based on the results.
Background
Indicators are based on soil morphological properties that are
formed by the accumulation or loss of iron, manganese, sulfur, and
organic carbon (US Department of Agriculture, Natural Resources
Conservation Service, 1996). The most commonly used morphological
parameters in the indicators are soil color and soil color patterns. Soil
color and color patterns are mainly related to the oxidation state of Fe
compounds and the accumulation or depletion of Fe and Mn as
previously discussed in Chapter 2.
Indicators and interpretations of morphological characteristics
are based on the prevailing idea that soils with seasonally high water
tables have areas of redoximorphic concentrations and gray or low
chroma (< 2) matrix colors or depletions in the zone of fluctuation.
The assumptions are based on many studies that have documented
the relationships and correlation between morphological features and
saturation (Boersma et al., 1972; Veneman et al., 1976; Vepraskas
and Wilding, 1983; Franzmeier et al., 1983; Evans and Franzmeirer,
107
1986; Schwertmann and Taylor, 1989; Mausbach and Richatdson,
1994; Cogger and Kennedy, 1992).
Numerous studies, however, have found soils where seasonally
high water tables and low-chroma colors are not always well
correlated. Evans and Franzmeier (1986) reported seasonally
saturated soils with three or four chroma colors. Daniels et al. (1971)
found 3-chroma redox features in horizons that were saturated 25% of
the time. Vepraskas et al. (1974) found 5_2 chromas lacking in some
seasonally saturated soils with perched water tables. Franzmeier et al.
(1983) noted that some soils with periodic high water tables had 3
chromas. Vepraskas and Wilding (1983) found that soils with a
seasonally perched water table on backslope and toeslope positions
had color chromas
along ped faces.
The Field Indicator Committee recognizes that all hydric soils do
not show the characteristic morphologies on which the indicators are
based. Studies have documented cases were saturation has not
resulted in characteristic redoximorphic features. Bouma (1973)
described soils that had perched water tables for several months but
lacked redox features. Austin (1994) found in some Willamette Valley
soils that had saturation for durations less than 10% of the wet season
did not have redoximorphic features.
Some factors known to affect the development or visibility of
characteristic morphologies are: parent materials that are reddish
(high amounts of Fe) or grayish (low amounts of Fe); dark soils; soils
with high pH or low organic matter content; low soil temperatures; and
aerated groundwater. Other factors less studied but known to affect
morphological characteristics are isomorphous substitution of Al for
Fe in Fe oxides (Norrish and Taylor, 1961; Barron and Torrent, 1984)
and absorption of phosphorus by Fe oxides (Willet and Cunningham,
1983).
108
Methods
Evaluation of field indicators was deferred until the soil
morphology of each site was documented in complete profile
descriptions. The goal was to prevent any bias in determinations. The
field indicator guide was then applied to the soil profile descriptions of
each site.
The Field Indicator Committee recognizes the occurrence of soil
colors between the Munsell chips. The procedure for specifying soil
color requires that a chroma between 2 and 3 (as an example) should
be listed as 2+. A chroma of 2+ can not be rounded and would not
meet an indicator that requires a chroma of 2 or less (US Department
of Agriculture, Natural Resources Conservation Service, 1996).
The field indicators for "all soils" (A), for "loamy and clayey soils"
(F), and test indicators (T) were used. All indicators in these four
sections (F, A, TA, TF) that were designated for use in the publication's
"A" Land Resource Region (LRR) were considered.
Results and Discussion
All applicable indicators are given in Table 4.1 along with the
specific requirements of each indicator. The table also shows whether
the soils at each site met an indicator's requirements. If a soil did not
meet the requirements but came close to doing so, "deficiencies" in the
soil's morphology were noted. Although all applicable indicators were
considered, only the indicators that came close to matching the
morphology of the study site soils are discussed in detail.
The F3 Depleted Matrix indicator requires a layer at least 15 cm
thick starting within 25 cm of the soil surface that has a depleted
matrix of chroma 2 in 60% of the layer. A depleted matrix, as
outlined in the indicator's glossary, can range from a matrix value of 6
Table 4.1. Application of field indicators to the study area soils.
INDICATORS
REQUIREMENTS
MEET
CLOSE
REASON FAILED
mucky modified mineral layer > 10 cm
starting within 15 cm
None
None
no mucky mineral layer
layer with > 60% gleyed matrix
starting within 30 cm
None
None
no gleyed matrix
layer > 15 cm thick
starting within 25 cm
> 60% depleted matrix chroma < 2
None
Site 2
matrix 3+/2 (versus 4/2)
layer 13 cm thick
1) 4/2 layer 9 cm thick
2) layer 11 cm thick with
LOAMY AND CLAYEY SOILS
Fl
Loamy Mucky Mineral
F2
Loamy Gleyed Matrix
F3
Depleted Matrix
Site
3
30% 4/2+
F4
Depleted Below Dark Surface
F5
Thick Dark Surface
layer > 15 cm thick
starting within 30 cm
> 60% depleted matrix chroma < 2
layers above: < 3/2
None
layer > 15 cm thick
starting below 30 cm
> 60% depleted matrix chroma < 2
layers above: hue N and value < 3 to 30 cm
and < 3/1 in remainder of epipedon
None
Site
2
Site
3
None
matrix 3+/2
layer 13 cm thick
layers above: 3/2+
1) 50% depleted matrix
layer above 4/2 and 4/2+
no hue N epipedons
Table 4.1, Continued.
INDICATORS
REQUIREMENTS
MEET
CLOSE
layer > 10 cm thick
entirely within 30 cm
matrix < 3/1 and > 2% dist./prom. redox
or matrix < 3/2 and > 5% redox
Site 4
Site 2
matrix 3+/2
layer > 10 cm thick
entirely within 30 cm
with redox depletions of > 5/< 2
matrix < 3/1 and > 10% depletions or
matrix < 3/2 and > 20% depletions
None
None
no depletions
layer > 5 cm thick
entirely within upper 15 cm
redox conc. > 5% distinct/prominent
*Site 3
*Site 4
Site 2
faint redox conc.
*meets requirements, but for
use in closed depressions
Al
Histosols
> 40 cm organic soil material layer
in the upper 80 cm
None
None
not histosols
A2
> 20 cm thick surface horizon
of organic soil material
None
None
no histic epipedons
F6
Redox Dark Surface
F7
Depleted Dark Surface
F8
Redox Depressions
REASON FAILED
ALL SOILS
Histic epipedon
Table 4.1, Continued.
INDICATORS
A3
Black Histic
A4
Hydrogen Sulfide
A10
Muck
REQUIREMENTS
MEET
CLOSE
layer > 20 cm of peat, mucky peat, muck
starting within 15 cm
hue > 10YR, < 3/1
None
None
not histic
hydrogen sulfide odor
within 30 cm
None
None
no hydrogen sulfide odor
layer > 2 cm thick of muck
starting within 15 cm
matrix < 3/1
None
None
no muck
layer > 15 cm thick
60% depleted matrix < 2 chroma
starting below 30 cm
layers above: > 10YR, < 2.5 value to a
depth of 30 cm and < 3/1 remainder of
epipedon
None
None
no layers with < 2.5 value
above depleted matrix
REASON FAILED
TEST-LOAMY AND CLAYEY
TF 7
Thick Dark Surface 2/1
112
or more and chroma 2 or less with or without redox concentrations to
a matrix value of 4 and a chroma of 1 with 2% redox concentrations as
soft masses and/or pore linings. Site 2 soils failed the indicator due to
two slight deficiencies. The A3 horizon of Pit 2 soils had a matrix of
3+/2 and a layer thickness of 13 cm. Since colors cannot be rounded
to meet an indicator's requirements, the A3 horizon matrix with a
value of 3+ did not fall within the definition of a depleted matrix. In
addition, the horizon was 2 cm short of the thickness requirement.
Site 3 soils had two horizons whose morphologies were close to
the specifications of the F3 indicator. The A2 horizon had a depleted
matrix (4/2) but was only 9 cm thick. The 11 cm thick B/E horizon
failed the thickness requirement. In addition, the horizon had a
matrix color of 4/2+ that occupied only 30% of the horizon.
The F4 indicator, Depleted Below Dark Surface, has similar
requirements as the F3 indicator but starts within the upper 30 cm.
An additional requirement that layers above the depleted matrix have
values of 3 and chromas of 2 was included. The A2 horizon of Site
2 soils failed for the same reasons given above for the F3 indicator
plus the overlying horizons of Pit 2 had a matrix color of 3/2+. The
E/B horizon of Pit 3 failed this indicator due to a depleted matrix that
had only a 50% matrix color of 5/2 and because overlying layers had
matrix colors of 4/2 and 4/2+.
The F6 indicator, Redox Dark Surface, requires a layer at least
10 cm thick that is entirely within 30 cm of the soil surface with a
matrix color of 3/1 with ?_ 2% distinct/prominent redox
concentrations or a matrix color of 3/2 with ?_ 5% distinct/ prominent
redox concentrations. The soil of Site 4 had a positive result for this
indicator. Both the A2 and BA soil horizons of Pit 4 met the
requirements. The soil of Site 2 came very close to meeting the
113
requirements but failed because the A3 horizon had a matrix value of
3+.
The F8 indicator, Redox Depressions, requires a layer at least 5
cm thick entirely within the upper 15 cm that has 5% distinct or
prominent redox concentrations or pore linings. Site 2 soils failed
because of faint redox concentrations but Site 3 and Site 4 soils met
the requirements. However, this indicator's use is restricted to closed
depressions subject to ponding and cannot be considered as a positive
outcome for soils at Sites 3 and 4.
Conclusion
Site 2 and Site 3 soils did not comply with any of the fourteen
designated hydric field indicators. Site 4 soils did meet the F6
indicator. The soils of Site 2 came closer to meeting the morphological
requirements of some indicators than did the Site 3 soils, even though
the soils of Site 3 had longer saturation and reduction. The soils of
Site 3 had a slightly higher mean seasonal water table (9.8 cm vs. 12.6
cm), longer continuous duration of saturation (21.5 weeks vs. 19.5
weeks), lower average Eh values at 20 cm and 35 cm, and longer
duration of iron reduction (24.5 weeks vs. 22 weeks) than Site 2 soils.
The two main factors that prevented positive outcomes for Sites
2 and 3 soils were the inability to round colors that fell between color
chips and layer thickness requirements. A third factor was the lack of
at least 60% depleted matrix within a designated horizon. Site 2 soils
came closer to meeting requirements of the F6 indicator than to any
other indicator. Failure was due to a matrix of 3+/2 in the A3 horizon
versus the required 3/2 matrix color. Site 2 soils also failed the F3
indicator due to a matrix of 3+/2 versus a required value of 4 and by
being 2 cm too thin to meet the layer thickness requirement.
114
Soils of Site 3 came closer to meeting requirements of the F3
indicator than to any other indicator. There were two horizons of Site
3 soils that were considered for this indicator: (1) the A2 depleted
matrix (4/2) layer that was 9 cm versus a required 15 cm thick; and
(2) the E/B horizon that was 11cm thick and had a 30% depleted
matrix (4/2+) versus a required 60% depleted matrix.
The Witham Hill wet soil study site was visited in July 1997 by a
group from the Wet Soils Monitoring Project, members of the National
Technical Committee for Hydric Soils, and members of the Field
Indicator Committee. Holes were dug, field indicators were applied,
hydrologic and redox potential data were reviewed, and opinions
liberally expressed. Two consensus were reached in the field that day.
A majority felt that the matrix color of the A3 horizon at Site 2 was 3/2
versus the 3+/2 originally noted. This change would mean that the
soils of Site 2 would meet the F6 indicator. A second consensus was
that the soil morphology of Site 3 needed to be covered by an indicator,
since the hydrologic and redox potential data did indicate that the
soils of Site 3 were hydric.
Version 4 of the Field Indicators of Hydric Soils in the United
States (US Department of Agriculture, Natural Resources Conservation
Service, 1998) was issued in March 1998 during the writing of this
thesis. The new version has changed the way colors that fall between
Munsell color chips are applied. Color values now can be rounded to
the nearest color chip but chromas cannot. The change enables the
A3 horizon at Site 2, with the debated 3+/2 matrix color, to meet the
F6 indicator that required a _3/2 matrix.
A second change in the new version that affects the study site
soils is an addition to the F3 Depleted Matrix indicator. The addition
allows the layer thickness requirement to be lowered from 15 cm to 5
cm if the depleted matrix is within the upper 15 cm of the mineral soil.
115
The A2 horizon of soils at Site 3 now meet the requirements to enable
a positive response to this indicator.
Based on soil morphology, hydrologic regime and reductionoxidation conditions of the soils at the study site, recommendations to
the Field Indicator Committee would focus on layer thickness
requirements, the handling of soil colors between color chips, and the
60% requirement for a depleted matrix. Thickness requirements, as
noted by the change made to indicator F3 in the 1998 version, are
reconsidered on an indicator by indicator basis.
Guidelines based on soil color, a qualitative parameter whose
description is affected by many factors, are going to have indefinite
areas of interpretation. Identification of soil color in the field can vary
not only with the quality of light and soil moisture but with personal
assessment and unintentional bias. Although Munsell notations are
decimal and could be refined to any desired degree (Kollmorgen
Instruments Corporation, 1994), doing so on an individual basis in the
field would increase the personal assessment error factor. Rounding
of soil colors that fall between two color chips on the Munsell soil color
charts is the normal practice of soil surveyors (Soil Survey Division
Staff, 1993). Noting a (+/-) beside the chip number is an alternative if
more precision is required. However, in light of the technical factors
and the differences in personal assessment that exist in designating a
chip color, exactness is not probable. Rounding to the nearest color
chip seems a reasonable procedure that would allow for the variances
of personal judgement without jeopardizing the indicator's validity. In
fact, before the 1998 revision, the inability to round color values to the
nearest color chip would have, in the assessment of the author (and
that of several others), failed Site 2 soils from meeting the F6 indicator.
For these reasons, further consideration should be given to rounding
not only value but also chroma.
116
The B/E and E/B horizons of Pits 2 and 3 present a strong case
for reviewing the requirement that a depleted matrix make up 60% of a
horizon for many indicators. The B/E horizons ranged from 35%
depleted matrix at Site 2 to 30% depleted matrix at Site 3 and the E/B
horizons ranged from 60% depleted matrix at Site 2 to 50% depleted
matrix at Site 3. Other factors besides duration of saturation and
reduction need to be considered. There may be physical properties or
chemical processes that result in no net loss of iron or that prevent
removal of iron from a horizon while still having iron redistributed into
areas of segregated high and low chroma colors.
117
Chapter 5
HYDROPHYTIC VEGETATION AND WETLANDS AT THE WITHAM HILL
BACKSLOPE-FOOTSLOPE STUDY SITE
Introduction
The soils at Sites 2, 3, and 4 of the Witham Hill study area were
concluded to be hydric soils in Chapter 3. The determinations were
made in order to evaluate the field indicator's capability to identify
those soils that met the hydric soil definition on a selected hillslope.
However, the confirmation of the study site soils as hydric raises the
possibility of a wide occurrence of hillslope hydric soils in the
Willamette Valley and prompts the controversial question as to
whether the study area could be a jurisdictional wetland. The
objective of this chapter is to characterize the vegetation of the study
site and to determine if the study site area could be a jurisdictional
wetland according to federal regulations and current wetland
identification procedures.
Background
There are two regulatory definitions of wetlands, the U.S. Army
Corps of Engineers (USACE) 1977 definition, used by the USACE and
the EPA, and the 1985 Food Security Act (FSA) definition, used by the
Natural Resources Conservation Service. Wetlands are defined by the
USACE as "those areas that are inundated or saturated by surface or
groundwater at a frequency and duration sufficient to support, and
that under normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil conditions"
(Federal Register, 1982).
118
Wetlands have three essential characteristics and criteria:
wetland hydrology, hydric soils, and hydrophytic vegetation. The
physical and chemical characteristics of hydric soils and the presence
of hydrophytic vegetation are dependent on and are the result of the
hydrologic regime. This cause-and-effect relationship allows inference
among the three variables of wetlands. Vegetation is often used to
support the presence of hydric soils and is part of the supporting
documentation accepted by the Field Indicator Committee for review of
indicators and hydric soils. Hydrology, which is often difficult to
evaluate without costly and time demanding research, is often inferred
and characterized from the assessment of both soils and vegetation
(National Research Council, 1995). However, from a jurisdictional
standpoint for wetland determinations the three parameters are
independently determined.
The criteria and procedures for determining wetlands and
delineating their boundaries are in the National Food Security Act
Manual (NFSAM) (Soil Conservation Service, 1994) and the Corps of
Engineers Wetlands Delineation Manual (Environmental Laboratory,
1987). Federal regulations require the use of one of the manuals in
determining wetlands. The former is used for delineating wetlands on
agricultural lands by the National Resources Conservation Service
(NRCS) and the latter is for determinations by the U.S. Army Corps of
Engineers (USACE) and the Environmental Protection Agency (EPA) on
non-agricultural lands and for Section 404 permits. The 1987 Corps
manual will be the focus of this review and determination.
Wetland Hydrology Criterion
Wetland hydrology according to the Corps manual "encompasses
all hydrologic characteristics of areas that are periodically inundated
119
or have soils saturated to the surface at some time during the growing
season." Wetland hydrology involves three basic elements: inundation
or saturation, critical depth of saturation, and duration of inundation
or saturation in relation to growing season.
In the definition of wetlands, inundation refers to "a condition in
which water from any source temporarily or permanently covers a land
surface." Saturation, in the definition, refers to "a condition in which
all easily drained voids (pores) between soil particles in the root zone
are temporarily or permanently filled with water to the soil surface at
pressures greater than atmospheric." However, one of the primary field
hydrologic indicators, "visual observation of soil saturation"
(paragraph 49.b.2 in the 1987 manual), states that the "depth to
saturated soils will always be nearer the surface" than the water level
observed in a soil pit "due to the capillary fringe." Thus, the capillary
fringe (with negative pressure) is indirectly considered in the
determination of saturation and the requirement for saturation to the
surface.
Although no indication is given by the Corps on how to estimate
the capillary fringe zone, the range can be from 10 cm in very coarse
material to greater than 100 cm in fine-textured clays (Stephens,
1996). Austin (1993) found that the capillary fringe ranged from 10
cm in silt loam and silty clay loam to 20 cm in silty clay or clay soils, in
selected Willamette Valley soils.
The Corps does, however, discuss an acceptable depth to
saturation in paragraph 49.b.2, "it must occur within a major portion
of the root zone (usually within 12 inches of the surface) of the
prevalent vegetation. The major portion of the root zone is that portion
of the soil profile in which more than one half of the plant roots occur."
This reference could be taken as an indication that saturation within
the 12 inches (30 cm) of the surface is acceptable as a positive
120
indicator of wetland hydrology if the major portion of roots are within
this zone. The saturation requirement would concur with the hydric
soil definition established by the National Technical Committee for
Hydric Soils that requires saturation within the upper 30.5 cm. The
threshold also concurs with studies that found most roots in wetlands
are concentrated in the upper 30 cm (National Research Council,
1995) and that surface saturated conditions are not necessary for
development of wetland communities (Kelsey and Hootman, 1992).
Duration is based on continuous inundation or saturation
during the growing season. To be considered as having wetland
hydrology, an area must be "inundated or saturated to the surface
continuously for at least 5% of the growing season in most years (50%
probability of recurrence)" according to the Corps manual.
The growing season months of the mesic soil temperature regime
of Soil Taxonomy is assumed to be March-October (US Department of
Agriculture, Soil Conservation Service, 1991). However, the Corps
regards the soil temperature regimes that are based on broad regions
as not being sufficiently site-specific (HQUSACE, 1992). The primary
accepted definition of growing season is considered the portion of the
year when soil temperatures are above biologic zero (5°C or 41°F) at 50
cm beneath the soil surface, however, the Corps allows this period to
be approximated by the number of frost-free days. The "starting and
ending dates for the growing season are based on 28 degrees F air
temperature threshold at a frequency of 5 years in 10."
Other primary field hydrologic indicators for identifying wetland
hydrology include: visual observation of inundation or saturation,
watermarks, drift lines, sediment deposits, and drainage patterns.
Secondary field hydrologic indicators (requires two in the absence of a
primary indicator) include: oxidized rhizospheres in the upper 12
121
inches, water-stained leaves, local soil survey hydrology data for
identified soils, and the FAC-neutral test for vegetation.
Hydric Soils Criterion
The 1987 manual uses the most recent version of the National
Technical Committee for Hydric Soils (NTCHS) hydric soil definition
and hydric soil criteria. The current hydric soil definition was
discussed in Chapter 3. The current hydric soil criteria (criteria 3 and
4) require frequently ponded or flooded soils for long durations (7 days
to 1 month) or very long durations (greater than 1 month) during the
growing season.
The Field Indicators of Hydric Soils in the United States developed
by NTCHS are used as supplementary information but are not used by
the Corps for identifying hydric soils. The Corps lists several
indicators for determining whether a soil meets the definition and
criteria for hydric soils. The indicators include: organic soils, histic
epipedons, sulfidic material, aquic or peraquic moisture regime,
reducing soil conditions, soil colors, soils appearing on hydric soil
lists, iron and manganese concretions, high organic matter content in
surface horizons, streaking of subsurface horizons by organic matter,
and organic pans.
Hydrophytic Vegetation Criterion
The term hydrophyte originally referred to plants growing in
water or very wet soil (Tiner, 1991). Today, federal delineation
manuals define hydrophytic vegetation as the "sum total of
macrophytic plant life that occurs in areas where the frequency and
duration of inundation or soil saturation produce permanently or
122
periodically saturated soils of sufficient duration to exert a controlling
influence on the plant species present."
Wetland vegetation consists of plants that require soil saturation
to become established or to persist and those that tolerate the stresses
caused by soil saturation (National Research Council, 1995). Hydric
soils have at least periodic anaerobic conditions that result in absence
of oxygen, which is a common stress for most plants. The duration
and intensity of reduction determines the degree of stress. The greater
the reduction, as measured by the redox potential, the more severe the
stress on plants. Additional stress is caused when anaerobic
microbial activity results in various toxic products (Meek and Stolzy,
1978).
The 1987 USACE manual uses the National List of Plant Species
that Occur in Wetlands: 1988 National Summary (Reed, 1988) for
identification of hydrophytic vegetation as required by the 1987 rule
implementing the Food Security Act of 1985. The 1988 list originally
was developed as an appendix to the Classification of Wetlands and
Deepwater Habitats of the United States by Cowardin et al. (1979). The
National List of Vascular Plant Species that Occur in Wetlands: 1996
National Summary is a draft revision of the 1988 list. The revision was
developed to aid in determining the presence of hydrophytic vegetation
for wetland regulation under the Clean Water Act Section 404 and the
implementation of the swampbuster provisions of the Food Security
Act (National Research Council, 1995).
The national plant lists are divided into 13 regional lists
corresponding to the geographic regions developed for the National List
of Scientific Plant Names issued by the USDA in 1982 (National
Research Council, 1995). The division allows each species to be
assigned regional indicators to reflect ecotypic variation within species
123
from region to region. The national indicator status for each species is
the range of regional indicators.
The plant lists categorize vascular plants into five basic
"wetland indicator status" groups (Table 5.1). The indicator status is
based on the fidelity rating system that was created by the FWS during
the development of its Annotated National Wetland Plant Species Data
Base in the 1970's (National Research Council, 1995). The fidelity
rating is based on frequency of occurrence of a plant species in
wetlands and is used in evaluating the predominance of hydrophytic
vegetation.
Table 5.1. Wetland indicator category of plant species under natural
Conditions (from Reed, 1988).
Wetland Indicator Status
Obligate wetland
Facultative wetland
Facultative
Facultative upland
Upland
(OBL)
(FACW)^
(FAC)A
(FACU)A
(UPL)
Estimated
probability of
occurrence in
wetlands
Estimated
probability of
occurrence in
nonwetlands
>99%
<1%
67-99%
34-66%
1-33%
1-33%
<1%
34-66%
67-99%
>99%
A subdivided by (+) and (-) to specify a higher or lower portion of frequency
The five categories range from obligate wetland (OBL) species
that are virtually restricted to wetlands to upland (UPL) species that
are mostly excluded from wetlands. Facultative (FAC) species occupy
wetlands in varying degrees and thus were broken down into three
categories with a gradation of percentage of occurrence in wetlands
124
(Reed, 1988). Species not occurring in wetlands in any region are not
included on the list and are considered upland species. Other
designations include: NI for no indicator as there was insufficient
information, NA for no agreement as a consensus could not be
reached, and (*) for a tentative designation based on limited
information or conflicting reviews.
As can be seen by the categories, most plants that grow in
wetlands do not grow strictly in water or saturated soils but can exist
in terrestrial habitats over a range of moisture status. Out of the
nearly 7,000 vascular plant species found in U.S. wetlands, only 27
percent are "obligate wetland" species that nearly always occur in
wetlands (Federal Interagency Committee for Wetlands Delineation,
1989). About 21% are "facultative upland" species that have been
observed in wetlands, which illustrates species adaptations to wet
environments (Tiner, 1991).
Tiner (1991) discussed the ability of ecotypes, populations with
different genetically based morphological and/or physiological
characteristics, to adapt to specific environmental conditions that
differ from the typical species habitat. A hydrophytic plant could
represent an entire population of a species or only a subset of
individuals genetically adapted to their environment. The ability to
adapt results in plant communities that are commonly made up of
populations with differing affinities for wet conditions and makes the
use of the "predominance of hydrophytic vegetation" for evaluating the
vegetative criteria complicated.
In general, the indicator groups are indicative of different levels
of soil moisture: dominance of UPL and/or FACU species with low
amounts or absence of OBL or FACW species is evidence of infrequent
flooding or saturation; dominance by OBL or FACW species is
indicative of frequent or extended periods of flooding or saturation;
125
and dominance of 50% or more by OBL, FACW, or FAC species with
low amounts or absence of UPL species is evidence of saturation or
flooding (National Research Council, 1995). FAC and FACU are
considered less reliable indicators of a wetland since they are less
restricted to wetland conditions. However, their ecotypes can range
from populations that occur in slightly stressful moisture conditions to
populations that always occur in wetlands (National Research Council,
1995).
The basic vegetation indicator in the 1987 manual that is
considered indicative of hydrophytic vegetation is when more than
50% of the dominant species are OBL, FACW, or FAC. Under the
dominance measure, plant communities are considered predominantly
hydrophytic if more than 50% of the dominant species are
hydrophytic. Less abundant species are not considered in the
determination. The system is based on the assumption that dominant
taxa have adapted and reflect the long-term hydrologic regime. This
assumption could be a potential problem in marginal situations if the
nondominant species are better indicators of the hydrologic regime
(National Research Council, 1995).
Other indicators of hydrophytic vegetation in the 1987 manual
that can be used to strengthen a case for the presence of hydrophytic
vegetation are: visual observation of species growing in areas of
prolonged inundation and/or saturation; morphological, physiological,
and reproductive adaptations; and technical literature that provides a
strong indication that species present are commonly found in areas
where soils are periodically saturated for long periods.
126
Methods
The procedures in the 1987 manual allow alternative sampling
methods and the use of an alternative dominance measure called the
"50/20 rule" from the 1989 manual (Federal Interagency Committee
for Wetlands Delineation, 1989), which was developed and later
rejected.
Plant communities were evaluated at each of the main sites (Site
1 through 4). Since the vegetation consisted of diverse and patchy
herb communities, a multiple-quadrant sampling approach similar to
the methods presented in the 1989 manual was chosen. Five 0.50 m2
sampling units were chosen within a 2 m by 2.5 m grid area by using
a random numbers table. The sampling units were located 1 m north
of each equipped site in order to avoid disturbance of vegetation when
measuring soil and hydrology parameters. The units were sampled in
the middle of May and the first week of June to encompass early and
late emergent plant species.
Vegetation was described in terms of species composition and
relative abundance of species. Abundance was measured by
estimating percentage of the sampling area covered by vertical
projection of plant foliage onto the quadrats. The most abundant
species were considered the dominant species. The alternative "50/20
rule" given in the 1989 federal manual was used for selecting
dominant species. The basic dominance method was also applied in
order to see if the outcome would be the same. However, the basic
method was not used because the sampling method for
"comprehensive determination" in the 1987 manual is based on a
number of observation points along several transects with one
sampling quadrant at each observation point. Determination of
dominant species according to the "50/20 rule" is accomplished by:
first ranking the species by their mean cover, beginning with the most
127
abundant species; determining the dominance threshold number,
which is 50% of the total mean cover; then cumulatively summing the
mean cover of the ranked species beginning with the most abundant
until 50% of the total for all species mean cover (threshold number) is
immediately exceeded. All species contributing to the cumulative total
plus additional species having 20% of the total mean cover value is
considered a dominant species (Federal Interagency Committee for
Wetlands Delineation, 1989).
Once plants were identified by genus and species, the National
List of Plant Species that Occur in Wetlands: 1988 National Summary
(Region) and the 1993 Northwest Region 9 Supplement were consulted
to determine the "wetland indicator status" of each plant. Although
the National List of Vascular Plant species that. Occur in Wetlands: 1996
Northwest (Region 9) draft has been issued, a January 1996
memorandum by the Corps warns that changes to the 1988 national
plant list or regional versions of the national list should not be used
until official approval.
Results and Discussion
Wetland Hydrology
As mentioned earlier, wetland hydrology according to the
Corps "encompasses all hydrologic characteristics of areas that are
periodically inundated or have soils saturated to the surface at some
time during the growing season." Although the hydrologic data from
the piezometers (Chapter 3) did not indicate surface saturation, the
soils at Sites 2, 3, and 4 had extended periods of saturation from
November through April in the major portion of the root zone (within
30 cm of the surface). The mean water table for the two field seasons
was 12.6 cm at Site 2, 9.8 cm at Site 3, and 5.5 cm at Site 4. In
128
addition, the soils at Sites 3 and 4 could be considered to be saturated
"to the surface" based on the mean water table data and assumed
capillary rise of at least 10 cm.
According to the 1987 manual, an area must be "inundated or
saturated to the surface continuously for at least 5% of the growing
season in most years (50% probability of recurrence)" to be considered
as having wetland hydrology. The growing season would be 365 days
based on soil temperature above biological zero (5°C or 41°F) at 50 cm
beneath the soil surface, since the soil temperature never reached this
threshold. Based on frost-free days, 28° F temperature threshold for a
frequency of 5 years in 10 years, the growing season in Benton County
would be from March 15th to November 10th for a total of 240 days
(Soil Survey Staff, 1975a). Based on "5% of the growing season", 5
percent would be 18 days or 12 days depending on whether the
"biological zero threshold" or "28° F temperature threshold" was used
to determine the growing season.
Saturation data were given in Table 3.1. The data show that
continuous saturation within the upper 30 cm occurred at: Site 1 for
two, one-week duration periods, Site 2 for an average of 19.5 weeks
(136.5 days), Site 3 for an average of 21.5 weeks (154 days), and Site 4
for an average of 24 weeks (168 days).
If the "biological zero threshold" were used for determining the
growing season, the periods of saturation "during the growing season"
far exceed the 18 days continuous saturation requirement. If the "28°
F temperature threshold" were used to determine growing season, the
only applicable times of saturation would be after March 15th. Soils at
Site 2 would have been considered to have continuously saturated
soils for 21days (to 4/04/96) the first growing season and 22 days (to
4/05/97) the second growing season. Soils at Site 3 would have had
continuously saturated soils for 21 days (to 4/04/96) the first growing
129
season and 50 days (to 5/03/97) the second growing season. Site 4
soils would have had 51 days (to 5/04/96) the first growing season
and 57 days (to 5/10/97) the second growing season.
Either of the growing season methods results in Sites 2, 3, and 4
meeting the wetland hydrology criteria. However, the wetland
classification would be different depending on which growing season
method was used. Based on the "biological zero" growing season, Sites
2, 3, and 4 would be classified (according to paragraph 48, Table 5 in
the 1987 manual) as hydrologic zone III "regularly inundated or
saturated" wetland since duration of saturation is >25% - 75% of the
growing season. Based on the "28° F temperature threshold" growing
season, Site 2 would be classified as a hydrologic zone V "irregularly
inundated or saturated" wetland because duration of saturation is 512.5% of the growing season. Site 3 and Site 4 would be classified as
hydrologic zone IV "seasonally inundated or saturated" wetlands,
which are saturated for > 12.5-25% of the growing season.
Hydric Soils
The 1987 manual uses the most recent version of the National
Technical Committee for Hydric Soils (NTCHS) hydric soil definition
and hydric soil criteria. The current hydric soil definition was
discussed in Chapter 3 where it was determined from data collected
for two years that the soils at Sites 2, 3 and 4 meet the hydric soil
definition and are hydric soils.
Hydrophytic Vegetation
Detailed characterization showing plant species and percent
areal cover of quadrants at Sites 1 through 4 is given in Appendix D.
Tables 5.2 through 5.5 show plant species present, their indicator
130
status, and dominance determinations. Although the alternative
"50/20" rule was used for selecting dominant species, the tables also
show which five species would have been considered dominant if cover
classes that are used in the 1987 manual had been considered. Also
included, but not utilized in the determinations, is the indicator status
given in the 1996 National List of Vascular Plant Species that Occur in
Wetlands.
Site 1 (Table 5.2), located on the backslope, had a plant
community dominated by Arrhenatherum elatius (Tall Oatgrass) and
Agrostis tenuis (Colonial Bentgrass). The indicator status for the
former is UPL and the indicator status of the latter is FAC. If the basic
dominance rule in the 1987 manual had been used, the additional
dominant species would be Poa pratensis (FAC), Festuca dertonensis
(upland) and Galium aparine (FACU).
Site 2 (Table 5.3), located downslope from Site 1, had a plant
community dominated by Agrostis stolonifera (Creeping Bentgrass),
Festuca rubra (Red Fescue), and Festuca arundinacea (Tall Fescue).
The indicator status for A. stolonifera was changed from a FAC+ to
FAC* in the 1993 supplement. The pending 1996 version changes the
status to FACW*. The indicator status for F. rubra is FAC+ and the
status for F. arundinacea is Fac-. At Site 2, the additional dominant
species using the basic dominance rule would be P. pratensis (FAC)
and A. tenuis (FAC).
Site 3 (Table 5.4) had a plant community dominated by Agrostis
stolonifera (Creeping Bentgrass) and Festuca rubra (Red Fescue).
Additional dominant species would be F. arundinaciea (FAC-), Holcus
lanatus (FAC) and Carex tumulicola (FACU*) for the basic rule.
Site 4 (Table 5.5) had a plant community dominated by
Alopecurus pratensis (Meadow Foxtail) and Lotus corniculatus (Birds-
Table 5.2. Dominance determination for Site 1.
SPECIES
Agrostis stolonifera L.
Agrostis tenuis Sibth.
Alopecurus pratensis L
Arrhenatherum elatus (L.) J. & K. Pres'
Brodiaea coronaria (Salisb.) Engl.
Brodiaea hyacinthina (Lindl.) Baker
Bromus commutatus Schrad.
Bromus mollis Schrad.
Carex densa (L.H. Bailey) L.H. Bailey
Carex leporina L.
Cardamine oligosperma Nutt.
Carex tumulicola Mackenzie
Carex unilateralis Mackenzie
Cerastium viscosum L.
Cirsium vulgare (Savi) Ten.
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Schultes
Epilobium glandulosum Lehm.
Festuca dertonensis (All.) (F. bromoides)
Festuca pratensis Huds.
Festuca rubra L.
Festuca arundinacea Schreb.
50/20 RULE
BASIC DOMINANT RULE
INDICATOR STATUS *
Mean %
1996 Mean %
1993
1988
List
areal Rank Dom. areal Cover Mid- Rank
PNW
List
spec. cover
cover
class point
Suppl.
FAC+
FAC*
FACW*
FAC
FACW
UPL
FACW
UPL
UPL
OBL
FAC
FACW
FACW
UPL
FACU
24.0
2
*
24.0
2
15
48.0
1
*
48.0
3
37.5
1
2.5
2.5
0.2
0.2
0.2
0.2
0.6
0.4
0.6
0.4
1
1
2.5
2.5
15.0
2
15
OBL
FACW FACW
FAC
FAC
FACU* FACU
FACW
FACU
_
OBL
OBL
15.0
FACU+
FAC
FACU-
1
2
FAC+
FAC-
4
FAC+
A
4
Table 5.2, Continued.
SPECIES
Galium aparine L.
Geranium dissectum L.
Holcus lanatus L.
Juncus effusus L.
Juncus tenuis Wilid.
Lotus comiculatus L.
Montia fontana L.
Montia linearis (Dougl.) Greene
Myosotis discolor Pers.
Parentucellia viscosa (L.) Caruel
Poa pratensis L.
Ranunculus orthorhynchus Hook.
Rumex acetosella L.
Trifolium dubium Sibth.
Trifolium spp.
Veronica arvensis L.
Vicia sativa L.
INDICATOR STATUS *
50/20 RULE
BASIC DOMINANT RULE
1988
1993
1996 Mean %
Mean %
List
PNW
List
areal Rank Dom. areal Cover Mid- Rank
Suppl.
cover
spec. cover class point
FACU
FACU
2.2
5
2.2
1
2.5
5
0.6
0.6
1
2.5
FAC
FACW+
FAC
FAC
OBL
FAC
FACW FACW
FACW- FACWFAC
OBL
FACW
FACFACU+
FACWFACU
UPL
FACW
FACFAC
FAC
FACW
FACU+ FACU+
UPL
0.6
19.5
0.6
FACU+ FACU+
UPL
3
0.6
1
2.5
19.5
2
15
0.6
1
2.5
UPL
0.6
0.6
1
2.5
Total mean cover =
112.5
Dominance Threshold Number = ( 50% x total mean cover) =
56.25
20% of the total mean cover = (.20 x 112.5) = 22.5
* All species without an indicator status are considered upland plants
3
Table 5.3. Dominance determination for Site 2.
SPECIES
Agrostis stolonifera L.
Agrostis tenuis Sibth.
Alopecurus pratensis L
Arrhenatherum elatus (L.) J. & K. Presl
Brodiaea coronaria (Salisb.) Engl.
Brodiaea hyacinthina (Lindl.) Baker
Bromus commutatus Schrad.
Bromus mollis Schrad.
Carex densa (L.H. Bailey) L.H. Bailey
Carex leporina L.
Cardamine oligosperma Nutt.
Carex tumulicola Mackenzie
Carex unilateralis Mackenzie
Cerastium viscosum L.
Cirsium vulgare (Savi) Ten.
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Schultes
Epilobium glandulosum Lehm.
Festuca dertonensis (All.) (F. bromoides)
Festuca pratensis Huds.
Festuca rubra L.
Festuca arundinacea Schreb.
INDICATOR STATUS *
50/20 RULE
BASIC DOMINANT RULE
1988
1993
1996 Mean %
Mean %
List
PNW
List
areal Rank Dom. areal Cover Mid- Rank
cover
Suppl.
spec. cover class point
FAC*
FACW*
FAC+
32.5 2
32.5
3
37.5
2
FAC
3.7
1
3.7 5
2.5
5
FACW
UPL
FACW
UPL
UPL
OBL
FAC
FACW
FACW
FAC
FACU*
FACW
UPL
FACU
0.2
1
2.5
0.2
0.2
1
2.5
2.5
2.5
1
2.5
OBL
FACW
FAC
FACU
FACW
FACU
OBL
OBL
FACU+
FAC
FACU-
0.2
FAC+
FAC-
FAC+
34.1
27.4
1
3
*
34.1
27.4
3
3
37.5
37.5
1
3
Table 5.3, Continued.
SPECIES
Galium aparine L.
Geranium dissectum L.
Holcus lanatus L.
Juncus effusus L.
Juncus tenuis Willd.
Lotus corniculatus L.
Montia fontana L.
Montia linearis (Dougl.) Greene
Myosotis discolor Pers.
Parentucellia viscosa (L.) Caruel
Poa pratensis L.
Ranunculus orthorhynchus Hook.
Rumex acetosella L.
Trifolium dubium Sibth.
Trifolium spp.
Veronica arvensis L.
Vicia sativa L.
INDICATOR STATUS *
50/20 RULE
BASIC DOMINANT RULE
1988
1993
1996 Mean %
Mean %
List
PNW
List
areal Rank Dom. areal Cover Mid- Rank
Suppl.
cover
spec. cover class point
FACU
FACU
2.9
2.9
1
2.5
FAC
FACW+ FACW
FAC
FACWFAC
OBL
FAC
FACW
FACWFAC
OBL
0.2
0.2
1
2.5
FACW
FACFACU+ FAC
FACWFACU FACU+
UPL
FACW
FACFAC
FACW
FACU+
UPL
1.1
1.1
1
2.5
5.0
1
2.5
0.4
1
2.5
5.0
0.4
4
4
_
UPL
FACU+ FACU+
UPL
1.6
1.6
1
2.5
Total mean cover =
111.8
Dominance Threshold Number = ( 50% x total mean cover) =
55.9
20% of the total mean cover = (.20 x 111.8) = 22.4
* All species without an indicator status are considered upland plants
Table 5.4. Dominance determination for Site 3.
SPECIES
Agrostis stolonifera L.
Agrostis tenuis Sibth.
Alopecurus pratensis L
Arrhenatherum elatus (L.) J. & K. Presl
Brodiaea coronaria (Salisb.) Engl.
Brodiaea hyacinthina (Lindl.) Baker
Bromus commutatus Schrad.
Bromus mollis Schrad.
Carex densa (L.H. Bailey) L.H. Bailey
Carex leporina L.
Cardamine oligosperma Nutt.
Carex tumulicola Mackenzie
Carex unilateralis Mackenzie
Cerastium viscosum L.
Cirsium vulgare (Savi) Ten.
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Schultes
Epilobium glandulosurn Lehm.
Festuca dertonensis (All.) (F. bromoides)
Festuca pratensis Huds.
Festuca rubra L.
Festuca arundinacea Schreb.
INDICATOR STATUS *
50/20 RULE
BASIC DOMINANT RULE
1988
1993
1996 Mean %
Mean %
List
PNW
List
areal Rank Dom. areal Cover Mid- Rank
Suppl.
cover
spec. cover class point
FAC+
FAC*
FACW*
36.0
36.0
3
37.5
1
_
FAC
2.4
2.4
1
2.5
FACW
FACW
0.3
0.3
1
2.5
UPL
UPL
0.4
4.5
UPL
OBL
FAC
FACW
FACW
FAC
FACU*
FACW
UPL
FACU
OBL
FACW
FAC
FACU
FACW
FACU
OBL
OBL
FACU+
FAC
FAC+
FACU- FAC-
FAC+
0.4
4.5
1
0.2
5.0
1
0.3
0.4
0.2
0.3
0.4
0.2
1
28.0
28.0
11.9,
0.2
5.0
11.9
5
3
1
1
1
1
3
2
2.5
2.5
_
2.5
2.5
2.5
2.5
2.5
37.5
15
.
2
Table 5.4, Continued.
SPECIES
Galium aparine L.
Geranium dissectum L.
Holcus lanatus L.
Juncus effusus L.
Juncus tenuis Willd.
Lotus corniculatus L.
Montia fontana L.
Montia linearis (Dougl.) Greene
Myosotis discolor Pers.
Parentucellia viscosa (L.) Caruel
Poa pratensis L.
Ranunculus orthorhynchus Hook.
Rumex acetosella L.
Trifolium dubium Sibth.
Trifolium spp.
Veronica arvensis L.
Vicia sativa L.
INDICATOR STATUS *
50/20 RULE
BASIC DOMINANT RULE
1988
1993
1996 Mean %
Mean %
List
PNW
List
areal Rank Dom. areal Cover Mid- Rank
Suppl.
cover
spec. cover
class point
FACU
FACU
0.9
1
0.9
2.5
0.4
0.4
1
2.5
FAC
FAC
9.8 4
9.8
2
15
4
FACW+ FACW
FAC
FACWFAC
OBL
FACW
FACWFAC
OBL
FACW
FACFACU+ FAC
FACWFACU FACU+
UPL
FACW
FACFAC
FACW
FACU+
UPL
UPI,
FACU+ FACU+
UPL
2.5
2.5
1
2.5
1.4
1.4
1
2.0
2.0
1
2.5
2.5
1.4
1.4
1
2.5
1
1
2.5
2.5
=
54.2
0.4
0.4
Total mean cover =
108.4
Dominance Threshold Number = ( 50% x total mean cover)
20% of the total mean cover = (.20 x 108.4) = 21.7
* All species without an indicator status are considered upland plants
Table 5.5. Dominance determination for Site 4.
SPECIES
Agrostis stolonifera L.
Agrostis tenuis Sibth.
Alopecurus pratensis L
Arrhenatherum elatus (L.) J. & K. Presl
Brodiaea coronaria (Salisb.) Engl.
Brodiaea hyacinthina (Lindl.) Baker
Bromus commutatus Schrad.
Bromus mollis Schrad.
Carex densa (L.H. Bailey) L.H. Bailey
Carex leporina L.
Cardamine oligosperma Nutt.
Carex tumulicola Mackenzie
Carex unilateralis Mackenzie
Cerastium viscosum L.
Cirsium vulgare (Savi) Ten.
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Schultes
Epilobium glandulosum Lehm.
Festuca dertonensis (All.) (F. bromoides)
Festuca pratensis Huds.
Festuca rubra L.
Festuca arundinacea Schreb.
50/20 RULE
INDICATOR STATUS *
BASIC DOMINANT RULE
Mean %
1993
1996 Mean %
1988
List
areal Rank Dom. areal
Cover Mid- Rank
List
PNW
cover
spec. cover
class point
Suppl.
4
15
FACW*
10.9
4
10.9
2
FAC*
FAC+
FAC
FACW
UPL
FACW
UPL
UPI,
OBL
FAC
FACW
FACW
30.5
2
13.7
3
*
30.5
3
37.5
2
13.7
2
15
3
_
OBL
FACW FACW
FAC
FAC
FACU* FACU
FACW
UPL
FACU
FACU
OBL
OBL
4.4
5.0
4.4
5.0
1
1
2.5
2.5
_
2
15
0.2
7.1
0.2
1
2.5
4.8
2.2
4.8
2.2
1
2.5
2.5
7.1
_
_
FACU+
FAC
FACU-
FAC+
FAC-
1
FAC+
.
Table 5.5, Continued.
SPECIES
Galium aparine L.
Geranium dissectum L.
Holcus lanatus L.
Juncus effusus L.
Juncus tenuis Wilid.
Lotus corniculatus L.
Montia fontana L.
Montia linearis (Dougl.) Greene
Myosotis discolor Pers.
Parentucellia viscosa (L.) Caruel
Poa pratensis L.
Ranunculus orthorhynchus Hook.
Rumex acetosella L.
Trifolium dubium Sibth.
Trifolium spp.
Veronica arvensis L.
Vicia sativa L.
INDICATOR STATUS *
50/20 RULE
BASIC DOMINANT RULE
1988
1993
1996 Mean %
Mean %
List
PNW
List
areal Rank Dom. areal
Cover Mid- Rank
Suppl.
cover
spec. cover
class point
FACU
FACU
FAC
FACW+
FAC
FAC
OBL
FAC
FACW FACW
FACW- FACWFAC
OBL
FACW
FACFACU+
FACWFACU
UPL
FACW
FACFAC
FAC
FACW
FACU+ FACU+
UPL
UPL
FACU+ FACU+
UPL
3.0
8.5
5
1.5
71.8
0.6
0.8
5.8
1
*
3.0
8.5
2
15
1.5
1
1
2.5
62.5
2.5
2.5
2
15
71.8
0.6
0.8
5.8
1
1
1
2.5
Total mean cover =
170.8
Dominance Threshold Number ( 50% x total mean cover)
85.4
20% of the total mean cover = (.20 x 170.8) = 34.2
* All species without an indicator status are considered upland plants
5
1
139
foot Trefoil). The indicator status for A. pratensis is FACW and L.
corniculatus has a FAC status. Additional dominant species under the
basic rule would be Bromus commutatus (upland), A. stolonifera (FAC*),
and Juncus effusus (FACW).
Hydrophytic vegetation is considered present when more than
50% of the dominant species are OBL, FACW, or FAC (FAC- has less
probability of occurring in wetlands than FAC). The "50/20" rule
resulted in three dominant species at Site 2 and only two dominant
species at Sites 1, 3, and 4. In order for the community to be
dominated by hydrophytic vegetation, both species would need to be
FAC or wetter at the latter sites. Under these guidelines and the
"50/20" rule, Sites 2, 3, and 4 had hydrophytic vegetation. Even with
the additional dominant species under the basic dominant rule, Sites
2, 3, and 4 would meet the 50% dominant measure.
Plant community composition on the upper slope showed no
sharp discontinuities; however, a downslope transition was apparent.
The transition zone between Site 1 and Site 2 started at Plot B with a
change from A. elatus to F. rubra and F. arundinacea. Holcus lanatus
and Juncus tenuis began appearing with variable occurrence at Site 2.
Both increased downslope but still did not occur uniformly. A.
pratensis appeared at Site 3 and increased downslope. Other species
that occurred in areas around Site 3 but were not in the sampling
quadrants were Briza minor (FAC), Camassia quamash (FACW*), and
Juncus bufonius (FACW+).
Conclusion
The criterion for wetland hydrology was met by soils at Sites 2,
3, and 4 based on saturation within 30 cm of the soil surface. The
soils of Sites 2, 3, and 4 met the requirements in the hydric soil
140
definition as determined in Chapter 3 and, therefore, met the hydric
soil criterion. Sites 2, 3, and 4 had hydrophytic vegetation based on
the 50% dominance measure. Therefore, Sites 2, 3, and 4 met the
three essential characteristics and criterion of wetlands and would be
considered jurisdictional wetlands by federal regulations.
In this study, plant communities that are dominated by more
than 50 percent facultative (FAC) species satisfied the hydrophytic
vegetation criteria at Sites 2 and 3. Controversy continues over FAC
species and the application of the "50% rule" since FAC species have
broad ecological amplitude and have no affinity for either wetlands or
nonwetlands. The 1987 manual does allow vegetation dominance to
be computed without the inclusion of facultative species ("FACneutral" tests) in some circumstances. However, studies on sites
dominated by facultative species showed eliminating FAC species from
the determination resulted in the failure to exceed the 50% threshold
even on poorly drained hydric soils (National Research Council, 1995).
Since Sites 2 and 3 had positive indicators for both wetland hydrology
and hydric soils, the FAC plant communities are considered indicative
of hydrophytic vegetation (Step 13.a. pg. 70) by the Corps.
141
Chapter 6
GEOMORPHOLOGY AND STRATIGRAPHY OF THE WITHAM HILL
BACKSLOPE-FOOTSLOPE STUDY SITE
Introduction
Soil development and morphological characteristics are greatly
influenced by geomorphic setting and stratigraphy. Landscape and
stratigraphy to a large degree control the flow of energy and water
(Mausbach and Richardson, 1994) that are major factors in
pedogenesis and in the formation of hydric soils. The objective of this
investigation was to obtain information that would further our
understanding of the geomorphic processes that resulted in the
present hydrology, morphological characteristics, and development of
hydric soils at the study site. Review of past research on the geology
and geomorphic associations in the Willamette Valley in addition to
mineralogical analyses were use to identify geomorphic surfaces,
determine stratigraphic units, and identify possible sources of soil
materials.
Background
Landscape position usually dictates water movement
(Richardson, et al., 1992) that in turn influences the moisture status,
distribution of soluble materials, and soil development. Hydric soils
are found predominately in flat landscapes such as floodplains,
depressions, backwater areas, and landscapes that have closed
drainage systems. Landscapes with relief and open systems are
normally not considered as being wet and usually have well drained to
moderately well drained soils (Mausbach and Richardson, 1994).
Stratigraphy influences soil characteristics by altering a
landscape's hydrology. Stratigraphic units can provide a vertical
142
textural contrast that affects hydraulic conductivity, water flow, and
soil drainage (Mausbach and Richardson, 1994). In addition, the
unit's continuity and distribution affect the direction of subsurface
water movement (Richardson and Daniels, 1993).
Soil-geomorphic-stratigraphic relationships in foothills of the
Willamette Valley are complex due to lithostratigraphic units and
geomorphic surfaces consisting of materials of different origin and age
from different erosional and depositional events (Glasmann et al.,
1980). Studies and mapping of stratigraphic units and geomorphic
surfaces in the Willamette Valley have been extensive in the last 30
years.
Geomorphic surfaces, portions of the landscape "specifically
defined in space and time" (Ruhe, 1975) that represent episodes of
landscape development, were initially defined and mapped in the valley
by Balster and Parsons (1968). This and other research (Balster and
Parsons, 1969; Parsons, et al., 1968; Parsons, et al, 1970)
demonstrated the correlation between soil, stratigraphy, and
geomorphic surfaces of the valley. Models of stratigraphic units,
geomorphic surfaces, and the relationship between the stratigraphy
and soils were developed. However, most of the studies and research
have focused on the regional silty and clayey soils of the valley floor
terraces. Some site-specific studies (Gelderman, 1970; Gelderman and
Parsons, 1972; Glasmann and Kling, 1980; Glasmann et al., 1980)
have been done on the higher pediments and foothills but no
comprehensive valley-wide studies have been published.
Mineralogical characteristics of soils have been used as an aid in
the delineation of stratigraphic units and geomorphic surfaces and the
identification of material origin. The types of minerals, weathering
status of minerals, and clay content, can be used to identify lithologic
discontinuities that differentiate among stratigraphic units (Ruhe,
143
1975). Mineral composition reflects the environment in which parent
material and soils were formed, while the weathering status of
minerals and mineral distribution in soil profiles is an indication of the
uniformity of soil development.
A sequence of weathering from the bedrock upward may be seen
in the micas and clays (Cady, 1960) in a residuum soil profile. The
intensity of weathering in a residual soil decreases progressively down
through the profile. Weathering combined with clay movement usually
results in an accumulation of a relatively large amount of one clay in a
particular horizon (Cady, 1960). Mica is mostly a primary mineral and
thus the amount and size of mica is greatest in bedrock and
progressively decreases upwards with the increase in weathering.
Through weathering, mica can alter to vermiculite, which further
weathers to smectite, chlorite, and kaolinite (Fanning and Keramidas,
1977). Smectite can be weathered further to kaolin or chlorite. Kfeldspar weathers to kaolinite or halloysite while plagioclase feldspar
weathers to smectite. Due to mica and feldspar weathering and
downward clay translocation (mostly smectite), more vermiculite and
kaolinite are expected in the upper horizons and more smectite and
halloysite in the subsurface horizons. The presence of better-ordered
kaolin with depth is due to geologic kaolin instead of pedogenic kaolin.
The soil environment also influences the location and relative
amounts of minerals in a soil profile. Smectite is more abundant in
moist conditions and, therefore, can increase with depth or in lower
footslope and toeslope positions. Chlorite, chloritic intergrades, and
kaolinite usually occur in dryer conditions in the upper profile or on
summit and shoulder positions.
Crystalline mineral components can be identified and
semiquantitative estimates of their relative abundance in soils can be
made by X-ray diffraction (XRD) analysis (Moore and Reynolds Jr,
144
1989). Each mineral has distinctive diffraction angles resulting from
interatomic distances within crystalline structures. XRD produces
peaks on a graph corresponding to angles of diffraction from the
mineral crystalline spacing. The minerals can be identified and
distinguished from one another by subjecting the sample to various
treatments, running the XRD for each treatment, and observing the
peaks which show the effect on the interplanar spacing along the axis
perpendicular to the platy surfaces (Soil Survey Staff, 1996).
Estimations of mineral concentrations are based on the intensities of
diffraction peaks, which are related to the number of diffraction planes
in a sample (Moore and Reynolds Jr, 1989).
Geological Overview
The Willamette Valley in western Oregon is located
approximately 40 miles inland from the Pacific Ocean (Fig. 6.1). The
valley is about 130 miles in length and 20-40miles in width and
occupies about 3,500 square miles (Orr et al., 1992). The valley is
divided physiographically into two units by the Salem-Eola Hills
(Balster and Parsons, 1968) with the southern section narrower and
flatter (Baldwin, 1981). The Columbia River is the northern boundary.
The two ranges that enclose the valley the Coast Range to the west
and the Cascade Range to the east converge near Cottage Grove to
form the southern boundary (Baldwin, 1981). The Willamette River
flows northward, and with its numerous tributaries, drains the valley
to the Columbia.
Structurally the Willamette Valley is a forarc basin, a partially
enclosed downwarp, created by the formation and subsidence of
volcanic foundation rocks (Orr et al., 1992). According to Orr et al.
(1992), the area west of the Cascades was part of a broad continental
145
Figure 6.1. Physiographic provinces of Oregon.
146
shelf of the ocean during the early Eocene to Pliocene time. The
foundation rocks of the shelf were formed when a volcanic island chain
collided and accreted to the North American plate. A basin was
formed between the Cascades and the ridge of subsiding inactive
seamounts to the east of the accretion. The trough-like configuration
of the valley formed later with the uplift of the Coast Range and
continued subsidence of the basin.
The valley, from its creation, started filling with alluvial deposits
and isolated volcanic flows. During the Tertiary age, the partially
enclosed basin received submarine flows, breccias, and tuffaceous
sediments from a chain of volcanic peaks to the west of the thencurrent shoreline (Baldwin, 1981). These sediments were interfingered
with sediments from the Cascades, detritus from the Klamath terrain
(Snavely and Wagner, 1963), and marine deposits from the sea.
Today, the geology of the valley and surrounding foothills consist of
early Tertiary basalt, sandstone, and shale; Eocene to Miocene
sandstones, siltstones, and claystones; Plio-Pleistocene sediments
from the surrounding landscape and the Columbia River; and
Pleistocene lacustrine deposits from an external source of glacial-melt
runoff.
The unique and complex geologic history of erosional and
depositional events in the Willamette Valley has left lithostratigraphic
units and geomorphic surfaces consisting of materials of different
origin and age. The Pleistocene lacustrine deposits from large-scale
floods brought in sediments from outside provenances (Allison, 1953)
that have had a major influence on soil development in the valley. As
summarized by Orr et al. (1992), the multiple ice-age floods occurred
as Lake Missoula in Montana repeatedly filled and emptied in
catastrophic events when the Clark Fork River was dammed by ice
lobes and breached. The water rushed across Idaho, Washington, and
147
through the Columbia Gorge to form temporary lakes in the valley. The
lacustrine slackwater sediments and ice-rafted erratics (Allison, 1953)
settled on the valley floor and surrounding lower foothills
simultaneously with sediment from local fluvial events and other
internal geomorphic processes (McDowell, 1991).
The sediments from the "Spokane Flood" or "Bretz Floods" and
"Ancient Missoula floods" (Reckendorf, 1993) formed distinct banded
layers in the valley floor and lower pediments that Allison (1953)
named the Willamette Silts. Balster and Parsons (1969) redefined this
silty unit as the Willamette Formation and divided the formation into
four lithostratigraphic units based on morphology, mineralogy, and
aerial distribution. The youngest deposit is the Greenback Member
(12 ka -15 ka yrs., Reckendorf, 1993; 13 ka yrs., McDowell, 1991) and
is a light gray, silty material that has predominantly silt-sized quartz
and feldspars. Below the Greenback is the Malpass Member that is
massive gray clay with irregular thickness. Next, the Irish Bend
Member (50-60 ka yrs., Reckendorf, 1993; 35-40 ka yrs., McDowell,
1991) has brown, faintly bedded micaceous silts. This unit overlies the
Wyatt Member that is composed of local sandy and silty alluvium.
McDowell (1991) gives an overview of proposed stratigraphic schemes
of the Willamette Formation and discusses a two-stage developmental
model that has evolved for the stratigraphy and origin of the deposits.
Investigation
Soil samples were collected from soil pits at Sites 1, 2, and 3. A
trench 61.5 m (202 ft) long was excavated to a depth of 1.2 m (4 ft) on
the upper transect from above Site 1 to Site 3 at an absolute elevation
of 99.7-93 m (Fig. 3.1). Measurements of depths to horizons and
stratigraphic unit boundaries corresponding to those observed in pit
148
soil profiles were recorded at various points along the trench. Any
rock fragments found in the trench walls were tagged and their
positions recorded. A National Resource Conservation Service (NRCS)
soil survey crew determined absolute elevation of the sites with a laser
level from county benchmarks #441.
X-ray diffraction analyses were performed on samples from
selected soil horizons from Pits 1, 2, and 3 to identify and estimate the
relative proportions of the crystalline mineral components. Air-dry soil
samples were separated for analysis following procedures outlined by
Glasmann (J.R. Glasmann, 1997, Procedures for clay mineral
separation, Mimeographed handout, Dept. of Geosciences, Oregon
State University, Corvallis, Oregon) and are detailed in Appendix E. In
general, the traditional less than < 2gm fraction is used to prepare
oriented sample mounts that are free of most of the non-clay minerals
(Towe, 1974). However, even though clay is considered any colloidal
material < 2 1.1,M in size, clay minerals can be much larger (Moore and
Reynolds, 1989). Sample mounts of the <15 gm fraction were made in
order to identify any >2 gm clay minerals and non-clay minerals.
A paste method (Theisen and Harward, 1962) was used to make
oriented clay film mounts of <2 gm and <15 pm samples from selected
horizons. The slides of the <15 I.M1 material were equilibrated at Mg+2
54% relative humidity. Slides of the <2 pm material received five
different treatments: Mg+2 54% relative humidity, Mg+2-glycol, Mg÷2-
glycerol, K+54% relative humidity, and K+1100C. Pretreatment with
Mg+2 saturation insured homoionic clay specimens (de Kimpe, 1993)
and allowed the identification of basal peaks for most smectites (1515.5 A), mica (10 A), and kaolin (7.1-7.5 A). Further treatments were
necessary to distinguish vermiculite (14.2 A), chlorite (14.2 A), chloritic
intergrade (14-15 A), and beidellite (14-15 A) 001 basal peaks from
149
smectite 001 basal peak, to distinguish these minerals from each
other, and to discern between kaolinite and halloysite.
Analyses were made with a.Phillips XRG 3100 Automated XRD
unit using monochromatic Cu K.< radiation at 40kV and 35mA. The
slides were run in the 2-34° 20 portion of the spectra for the <2 p.m
Mg+2-glycol and the <15 pm Mg+2 54%RH samples. The <2 p.m
samples with the Mg+2 54%RH, Mg+2-glycerol, K+ 54%RH, and K+110°C
were run in the 2-14° 29 range. The "d" (A) values of the spacing of
reflections were observed for each treatment. Mineral identification
was based on "d" values from Brindley and Brown (1980) and JADE
Search/match software for computer facilitated mineralogy
interpretations. Relative proportions of minerals were determined by
the intensities of diffraction maxima.
Results and Discussion
Observations
Field observations of the substratum provided morphological
evidence of stratification. Two distinct banded clay units could be
traced up the hillslope in the trench where they thinned and tapered
to an end (Fig. 6.2). In addition, physical analysis confirmed there was
a significant change in particle-size distribution between the overlying
silty clay loam horizons and the clay horizons. The upper clay layer
(2Bt) is grayish brown (2.5Y 5/2) and tapers to an end at an absolute
surface elevation of 97.9 m and 89 cm below the surface. The
underlying clay layer (3l3ss) is light olive brown (2.5Y 5/4) and tapers
to an end at a surface elevation of 96.8 m and 124 cm below the soil
surface.
Both clay layers tapered to an end where a slight break in slope
is evident below Site 1 that is at an elevation of 99.1 m. At Site 2, the
Figure 6.2. Cross-section of the study trench showing the stratigraphy from Site 1 to Site 3.
102
100
92
90
C
2
D
Site locations along 61.5 meter trench
Cr, BC horizon
3B horizons
2B horizons
BA, Bw horizons
B/E, E/B horizons
A horizons
151
gray clay layer (2Btl) ranged from 70 cm to 92 cm beneath the soil
surface and the underlying olive clay layer (3Bss) ranged from 92 cm
to 142 cm beneath the soil surface. At Site 3, the gray clay layer (2Bt)
ranged from 42 cm to 91 cm beneath the soil surface and the
underlying olive clay layer (3Bss) ranged from 91 cm to 153 cm
beneath the soil surface.
Beneath the surficial clay loam layer at Site 1 was slightly
weathered bedrock that was light yellowish brown (2.5Y 7/3)
sandstone interbedded with siltstone. Light yellowish brown (2.5Y
6/3) highly weathered soft siltstone and / or sandstone was beneath
the lower olive clay layers at Sites 2 and 3. The weathered bedrock at
Site 2 had 28.8% sand content compared to 5.9% for Site 1 and 6.5%
for Site 3, which shows the bedrock variability.
The upper gray clay horizon has the same characteristics of the
massive gray clay described by Gelderman (1970) as the Malpass
Member of the Willamette Formation. The gray clay described by
Gelderman as "dense, cracks on drying into large polyhedral peds . . .
has slickensides, contains iron-manganese segregations, and has few
to common fine yellowish brown mottles" could very well be describing
the 2Bt horizon of Site 3. At the Witham Hill site, however, the gray
clay occurs at a higher elevation than the Malpass typically is found as
a stratigraphic unit beneath the Calapooyia surface on the valley floor
(Balster and Parsons, 1968, 1969; Parsons et al., 1970).
The Malpass Member is one of the least investigated and
understood units of the Willamette Formation, and its extent and
genesis are still debated. Reckendorf (1993) stated that the Malpass
has been found on the next higher Bethel surface, which is on
hillslopes below 80 m in elevation (Gelderman and Parsons, 1972).
Gelderman (1970) observed Malpass-like clays above 106 meter during
his research but found none on the Bethel unit or higher at his study
152
area near McCoy in Polk County. No other studies were found that
documented the Malpass Member above an elevation of 80 meters,
which would place it on the Brateng surface.
Some believe the Malpass clay is from glacial meltwater deposits
(Allison, 1953). Others speculate that part of the sediments could be
from a local source, possibly from eroded fine-textured soils on the
foothills and the claystones, siltstones, and tuffs of the Spencer
Formation (Reckendorf, 1993). Gelderman (1970) speculated that the
Malpass Member could be from material carried by turbidity currents
from topographic highs to topographic lows. Balster and Parsons
(1969) concluded the deposit was from the Willamette River systems.
Glasmann and Kling (1980) and Glasmann et al. (1980) defined
the Brateng surface that ranges from 80 to 122 meters in elevation
and includes low convex hilltops, sideslopes, and toeslopes that have
been mantled only by the Greenback Member. The Upper Brateng
surface ranges from 86 to 122 meters in elevation and has a paleosol
that is associated with the Spencer Formation. The Lower Brateng
ranges in elevation from 80 to 86 meters and lacks the paleosol.
Mineralogical Analysis
Soil samples from selected horizons from Sites 1, 2, and 3 were
analyzed by XRD. A sample of the 2Crt horizon of Site 1 (the site with
no clay layers) was analyzed. The diffraction patterns (Fig. 6.3) show a
mineral assemblage that includes smectite, vermiculite, mixed-layer
vermiculite/mica, mica, well-ordered kaolinite, quartz, plagioclase
feldspar and K-feldspar, and a trace of beidellite. Smectite was the
dominant clay fraction. The difference in the peaks between the two
size fractions indicate that a majority of the vermiculite and mica are
in the >2 pm fraction as expected.
153
Figure 6.3. XRD patterns of the 2Crt sample from Site 1.
(a) <1511m. (b) <21.1.m.
(a)
1-2Crt <15um Mg54%RH
[1] Mg-smectite, hydrated, n=3-7
[2] DIVERMICULITE .5 OIVERMICULJTE REICHW 0
[31 Ill to 2M#1 - (K,H30)Al2Si3A1010(OH)2
[4] Kaolinite <15urn Oriented Slide
[5] Quartz, syn - Si02
[6] Albite, calcian, ordered - (Na,Ca)AI(Si,AI)308
[7] Microcline, intermediate - KAISi308
5000-
4000-
4
17')
0 3000-
O)
"a.
2000-
6
5
10003
0
11111
5.0
4
II
)1
I
15
r
4
ti
I
20
2-Theta(deg)
25
117,",1
I
30
1-2Crt <2um
(b)
6000
1= Mg Glycol
2= K110C
3= K 54%RH
5000-
4= Mg54%RH
5= Mg Glycol
13-
1
4000-
0
3000-
2000-
1000-
5.0
10
15
20
2-Theta(deg)
25
30
I
1
154
Soils sampled at Site 2 were from the 2Btl, 3Bss, and 4BCt1
horizons. The 2Bt1 gray clay horizon <15 gm and <2 gm diffraction
patterns (Fig. 6.4) indicate that the mineral assemblage includes
smectite, beidellite, vermiculite, mica, ordered kaolinite, quartz,
plagioclase feldspar, K-feldspar, amphibole, and goethite. The sharp
mica and kaolinite peaks indicate well-ordered minerals that are not
highly weathered. Beidellite followed by smectite are the dominant
clay minerals. The less intense mica peaks in the <2 gm compared to
the <15 gm fraction indicate some of the mica is in the >2 gm range.
The olive clay 3Bss horizon sample from Site 2 (Fig. 6.5) has
similar diffraction patterns as the 2Bt1 horizon. The main differences
are that the 3Bss horizon has less mica, beidellite and vermiculite;
some disordered kaolinite; no amphibole; and an additional peak at
3.88 A that could be muscovite.
Site 2 soft bedrock 4BCt1 <15 gm and <2 gm diffraction
patterns (Fig. 6.6) show a mineral assemblage that includes smectite,
beidellite, vermiculite, mixed-layer vermiculite/ mica, mica, disordered
kaolinite, quartz, plagioclase feldspar, K-feldspar, and goethite. The
<2 gm patterns show that the clay mineralogy is very smectitic with
only a trace of vermiculite, beidellite, and mica. The sharp, intense
vermiculite and mica peaks in the <15 gm fraction show that the
majority of these minerals are in the >2 gm fraction as expected in
weathered bedrock.
At Site 3, samples of the 2Bt, 3Bsstyl, 3Bssty2, and 4BCt
horizons were analyzed. The diffraction patterns of the <15 gm and <2
gm fraction of the 2Bt gray clay horizon (Figs. 6.7) are very similar to
the 2Bt1 Site 2 diffraction patterns with the exception of having
disordered kaolinite. Both smectite and beidellite were the dominant
clay mineral.
155
Figure 6.4. XRD patterns of the 2Bt1 gray clay horizon of Site 2.
(a) <15pm. (b) <21.t.rn.
(a) 6000-
2-2Bt1 <15um Mg54%RH
[1] Mg-smectite, hydrated, n=3-7
[2] DIVERMICULJTE .5 DIVERMICUUTE REICHW 0
13) ltite -2M #1 - (K,H30)Al2Si3A1010(OH)2
141 Kaolinite <15um Oriented Slide
[5] Quartz, syn - Si02
[6] Albite, caldan, ordered - (Na,Ca)Al(SI,A1)308
[7] Microcline, intermediate - KAISi308
5000-
1r)
4000-
3000(7)
a)
6
2000-
10003
0
5.0
r
ITT
10
r
15
20
2-Theta(deg)
25
30
2-2Bt1 <2um
(b)
1= Mg Glycol
2= K110C
7500-
3= K 54%RH
4= Mg54%RH
5= Mg Glycol
5000=
0
to
E'
2500-
5.0
10
15
20
2-Theta(deg)
I
25
r
30
156
Figure 6.5. XRD patterns of the 3Bss olive clay horizon of Site 2.
(a) <151.1.m. (b) <21..tm.
2-3Bss <15um Mg54%RH
(a)
[1] Mg- smectite, hydrated, n=3-7
[2] DIVERMICULITE .5 DIVERMICULITE REICHW 0
[3]
- (K,H30)Al2Si3A1010(OH)2
[4] Kaolinite <15um Oriented Slide
[5] Quartz, syn - Si02
[6] Albite, calcian, ordered - (Na,Ca)Al(Si,A1)308
[7] Microcline, intermediate - KAISi308
6000
5000
3
1.13' 4000
C
4
O
0
3000
a)
2000
7
1000
5.0
10
15
20
25
30
2-Theta(deg)
2-3Bss <2um
(b) 4500-
1= Mg Glycol
2= K110C
4000-
3= K 54%RH
4= Mg54%RH
3500-
5= Mg Glycol
3000
° 2500
2 2000a)
C
15001-000
500-
5.0
10
15
20
2-Theta(deg)
2'5
30
157
Figure 6.6. XRD patterns of the 4BCt horizon of Site 2.
(a) <154m. (b) <24m.
(a)
2-4BCt1 <15um Mg54%RH
5000-
[1] Mg-smectite, hydrated, n=3-7
[2] DIVERMICULITE .5 DIVERMICULITE REICHW 0
- (K,H30)Al2Si3A1010(OH)2
r31
[4] Kaolinite <15um Oriented Slide
[5] Quartz, syn - S102
[6] Albite, caldan, ordered - (Na,Ca)Al(SLA1)308
[7] Microdine, intermediate - KAISi308
4000-
= 3000-
00
4
2000-1
1000-
7
4
Nr6,7
II Ili
5.0
10
15
20
2-Theta(deg)
mi
4
6
ki .11,1 I
25
7:16
e
NM I
30
2-4BCt1 <2um
(b)
1= Mg Glycol
2= K110C
3= K 54%RH
7500
4= Mg54%RH
5= Mg Glycol
2500
5.0
10
15
20
2-Theta(deg)
2'5
30
7
e
t
158
Figure 6.7. XRD patterns of the 2Bt gray clay horizon of Site 3.
(a) <15i.im. (b)
(a)
3-2Bt <15um Mg54%RH
[1] Mg-smectite, hydrated, n=3-7
[2] DIVERMICULITE .5 DIVERMICULITE REICHW 0
- (C,H30)Al2Si3A1010(OH)2
[3]
[4] Kaolinite <15um Oriented Slide
[5] Quartz, syn - S102
[6] Albite, calcian, ordered - (Na,Ca)Al(SLA0308
[7] Microcline, intermediate - KAISi308
50002
4000-
O
0 3000rD
6
20007
5
10003
6
111-11II
5.0
4
,
15
T
25
20
2-Theta(deg)
30
3-2Bt <2um
(b)
4500-
1= Mg Glycol
2= K110C
4000
3= K 54%RH
4= Mg54%RH
3500-
5= Mg Glycol
c?, 3000=
0
0 2500ca,
c
2000
15001000
500-
5.0
1110
1,111
15
2-Theta(deg)
1
i
1
r
25
I
r
r
r
r
30
r
I
159
The 3Bsstyl, 3Bssty2 of Site 3 are horizons that contained white
crystal clusters, white crystal strands, and clear crystals that started
at a depth of 102 cm and are believed to be gypsum. The majority of
the crystals are in the forther horizon. Bulk random powder mounts
were examined (Chapter 2) on the 3Bsstyl that confirmed the crystals
are gypsum.
Diffraction patterns of oriented film mounts of the 3Bsstyl and
3Bssty2 (Fig. 6.8) <151.irn and <2 p.m fraction show almost identical
patterns as the overlying 2Bt horizon but there are some differences.
In the <2 pm fraction, there is less mica and kaolinite. Some
differences in the <15 gm fraction of the 3Bsstyl horizon are the
greater amount of quartz and an additional feldspar peak at 3.75 A.
The differences in the <15 µm fraction of the 3Bssty2 horizon include:
a smaller amount of quartz than in either the 2Bt or 3Bssty 1 samples;
a great increase in the K-feldspar peak 3.27 A intensity; and an
additional peak at 6.47 A that could be lepidocrocite.
The 4BCt soft bedrock patterns of Site 3 (Fig. 6.9) look similar to
the overlying clay horizons with the exception of an additional peak at
2.73 A that could be amphibole, a decrease in the relative quantity of
beidellite, and the lack of the high K-feldspar peak.
Interpretation
Geomorphology
The geomorphic surface of the upper transect at the study site is
believed to be the Upper Brateng surface over a completely truncated
paleosol. The Upper Brateng usually has the Spencer paleosol that is
lacking on the Lower Brateng surface. However, the authors that
defined the Brateng surfaces (Glasmann and Kling, 1980; Glasmann et
160
Figure 6.8. XRD patterns of the 3Bsstyl and 3Bssty2 olive clay
horizon of Site 3. (a) <15pm. (b) <2pm.
(a)
3- 3Bsstyl & 3Bssty2 <15um Mg54%RH
6000-
5000-
S 4000 o
0
-5;
(72 3000
o
2000-
1000-
5.0
(b)
6000
15
30
20
2-Theta(deg)
3- Bsstyl <2um
1= Mg Glycol
2= K110C
3= K 54%RH
5000-
4= Mg54%RH
5= Mg Glycol
4000-
0
l
3000-
2000-
1000
5.0
10
11111,1,,
15
20
2-Theta(deg)
1-V1
25
161
Figure 6.9. XRD patterns of the 4BCt horizon of Site 3.
(a) <151im. (b) <2gm.
(a)
3 -4BCt <15um Mg54%RH
5000-
[1] Mg-smectite, hydrated, n=3-7
[2] DIVERMICUUTE .5 DIVERMICUUTE REICHW 0
[3] Illite-2M #1 - (K,H30)Al2Si3A1010(OH)2
[4] Kaolinite <15um Oriented Slide
[5] Quartz, syn - Si02
[6] Albite, calcian, ordered - (Na,Ca)Al(Si,A1)308
[7] Microcline, intermediate - KAISi308
4000-
1r)
S 3000
O
0
4
2000
7
7
1000
7
sz
4
3
0
ti
5.0
(b)
10
15
20
2-Theta(deg)
25
3-4BCt <2um
1= Mg Glycol
2= K110C
6000-
3= K 54%RH
4= Mg54%RH
5= Mg Glycol
5000-
5.0
ITIII
10
1'5
20
2-Theta(deg)
25
30
162
al., 1980) did note that soil variability in the Brateng is high, and that
the paleosol above 86 m has been removed in some steep areas by
erosion or other influences from the valley floods and truncated to
some degree in most other areas. The Brateng surface typically has
Ultic Haploxeralf and Aquic Xerochrept soils (Reckendorf, 1993) which
was the original classification of the study site soils in the 1975 soil
survey (Soil Survey Staff, 1975).
The dark brown and grayish brown silt loam and clay loam
surface soils which are 42 to 70 cm thick on the upper part of the
transect are characteristic of the Greenback Member derived from late
Lake Missoula floods. Glasmann (1979) found the Greenback
deposition was 65-70 cm thick on upland sites and had an average
particle-size fraction of 25% clay, 55.4% silt, and 19.6% sand. Figure
6.10 shows a comparison of an XRD diffraction pattern of the AB
horizon (27-36 cm) from Site 2 with a diffraction pattern of the
Greenback Member from the Bethel surface (J.R. Glasmann, 1997, Xray Diffraction Laboratoly, Dept. of Geosciences, Oregon State
University, Corvallis, Oregon) taken from the OSU swine farm taken at
33-38 cm. The surface soils of the study area do not have interlayered
chloritic intergrade and are less micaeous than the Bethel surface.
The comparison shows that the Greenback Member is highly variable
in mineralogy. Glasmann (1979) found that in the Greenback, mica
peaks were more intense in samples from the valley floor compared to
those taken at higher elevations and that in elevations above 80 m
much of the Greenback material may be locally derived.
In addition, erratics were found that are thought to be indicative
of the Greenback Member. The Greenback has lightly weathered
erratic rock fragments of small pebbles to boulders (Glasmann and
Kling, 1980). The erratics include granite, quartzite, phyllite, slate,
163
Figure 6.10. XRD patterns of the AB horizon of Site 2 and a
Greenback sample from the Bethel surface. (a) Site 2.
(b) Bethel.
2-AB <2um Mg-Glycol
(a) 3000-
2500-
.17.)
2000 -
c
:5 1500a)
10001
500-
7
5.0
10
15
20
2-Theta(deg)
I
F
25
30
swine farm 33-38 cm <2um Mg-Glycol
(b)
3000
2500
-111 2000
0
1500
1000
500
1111
5.0
10
15
20
2-Theta(deg)
25
30
164
schist, gneiss, basalt, and granodiorite (Allison, 1935). These rocks
are foreign to the Willamette River watershed, which do not include
Pleistocene continental till and outwash (Reckendorf, 1993). Erratics
ranging from 3.5 cm to 11 cm in diameter were found in the study site
trench located from 53 cm to 71 cm below the soil surface and above
the upper gray clay layer. The erratics included fragments that were
metasedimentary quartzite and large grain mafic with amphibole (J.R.
Glasmann, 1997, Dept. of Geosciences, Oregon State University,
Corvallis, Oregon personal communication). Other erratics were found
as the sides of the trench sloughed in. These included altered volcanic
tuff and a metamorphic rock high in biotite.
The sites transect grades gently from the Upper Brateng surface
to the Ingram unit. The Ingram surfaces include the higher of two
flood plain levels of the Willamette River and landscapes associated
with smaller streams (Balster and Parsons, 1968). The alluvium of the
study site Ingram surface is from the latter. Three typical geomorphic
surfaces are not represented at this study site due to incision by the
Ingram unit. These geomorphic surfaces are the Lower Brateng, the
Bethel (Gelderman, 1970) which is characterized by Greenback over
Irish Bend, and the Calapooyia unit.
Stratigraphy
The mineralogical properties of clay horizons and weathered
bedrock at the Witham Hill study site were investigated to identify
stratigraphic units and possible source of material origin. Comparison
of the mineralogy between horizons at Sites 1, 2, and 3 shows little
lateral variation. Comparison of the relative amounts of clay minerals
and quartz in the <2 p.m and <15 prn fractions between horizons of
pedons at Site 2 and 3 are summarized in Tables 6.1 and 6.2. Relative
Table 6.1. Selected peak intensities for Site 2.
Horizons Smectite Beidellite j Vermiculite
xx
2Bt1
xxx
xxx
x
3Bss
xx
x
4BCt1
xxx
x
xx
Mica Kaolinite
xxx
xx
x
xx
x
xx
Quartz
xx
xxx
x
Table 6.2. Selected peak intensities for Site 3.
Horizons Smectite Beidellite
2Bt
x
xx
xx
3Bsstyl
xxx
3Bssty2
xx
xxx
4BCt
xxx
x
Vermiculite
x
x
xx
xx
Mica Kaolinite Quartz
xxx
xx
xx
x
xx
xxx
xx
x
x
xxxx
xx
x
166
peak intensities between horizons, not within horizons, (columns, not
rows) are denoted with X's with (x) the lowest and (xxxx) the highest
relative quantity.
Although the XRD patterns show that the mineralogy of the
sampled horizons is very similar, there are differences that indicate
discontinuities and that the clay horizons are not residual. The
distribution of minerals does not indicate normal weathering
horizonation. The relative peak intensities in Tables 6.1 and 6.2 and
the overlaid diffraction patterns of Site 3 in Figure 6.11 show that the
gray clay horizon (2Bt) is more micaceous than the underlying olive
clay horizons (3Bss). The increase in mica higher in the profile is
inconsistent with normal residual weathering were mica decreases
with increased weathering higher in a soil profile. The soft bedrock
(4BCt) horizon has lower amounts of quartz and a clay mineralogy that
is much more smectitic than the overlying clay horizons indicating
another lithologic discontinuity.
Mineralogical similarities between the gray and olive clay
horizons suggest that the two clay units may share a common origin.
Overall, the diffraction analysis of the <15 gm patterns indicate that
the mineralogy is rich in quartz and feldspars that are not severely
weathered, which suggest relatively young soils.
The possibility that the clays are sediments brought in with the
Missoula Floods is unlikely since the >2 gm size vermiculite, mica, and
feldspars in the clay horizons are not indicative of transported
sediments. Micas have soft characteristics that allow them to be
broken down during transport and sedimentation resulting in small
particles (Fanning and Keramidas, 1977) while feldspars break down
due to their easy cleavage (Williams et al., 1954).
The >2 gm size vermiculite, mica, and feldspars do not confirm
that the gray clay is not Malpass clay, since some researchers believe
Figure 6.11. XRD patterns of the <2 m Mg-Glycol samples from horizons at Site 3.
50001 = 2Bt
2 = 3Bssty1
3 = 3Bssty2
4000-
4 = 4BCt
0
(-)
3000-
a)
2000-
1000-
5.0
20
1I5
2-Theta(deg)
25
30
168
the Malpass is from local sources (Bolster and Parsons, 1969;
Gelderman, 1970) or a mixture of local and extra-valley provenance
(Reckendorf, 1993). However, comparison of an XRD diffraction
pattern of the 2Bt gray clay horizon (Fig. 6.12) with a diffraction
pattern of Malpass from the 2Bt1 horizon of a Dayton soil in Benton
county (NRCS site identification number 920R003005) indicates
dissimilar mineralogy.
The clays are believed to be derived from local slope-related
transport of colluvial material from the Spencer Formation after the
paleosol had been eroded away. The clays do not have the kaolinitic
mineralogy (Glasmann, 1979) associated with the Spencer Formation
paleosol. Mass-wasting of the paleosol down to bedrock on the study
site and once-higher landforms could have exposed the highly
weatherable Spencer Formation. Erosion of the formation could have
deposited clayey colluvial material on the footslopes.
Baldwin (1981) traced the Eocene Spencer Formation through
Corvallis and the surrounding areas. The upper part of the Spencer
Formation is fine to medium-grained arkosic and micaceous
sandstone, siltstone, claystones, and shale, with minor conglomerate
and tuffs (Baldwin, 1981). According to Glasmann et al. (1980), the
formation is friable and has lateral interfingering of different rock
types resulting in lithologic variability over short distances. The
authors noted that the fine-textured (clayey) beds have grayish brown
to light olive gray colors and to a lesser extent can have yellowish
brown to strong brown colors. Glasmann and Kling (1980) noted that
the clay mineralogy of the clayey weathered tuff, and the paleosol that
occurs over these tuffaceous beds show a dominance of smectite
(beidellite). Based on mineralogy of the clay horizons, the colluvium
had predominantly smectitic (partially beidellite) mineralogy and
169
Figure 6.12 XRD patterns of the 2Bt gray clay horizon of Site 3 and a
2Bt Malpass from a Dayton soil. (a) Site 3. (b). Dayton
(a) 4500-
3-2Bt <2um Mg-Glycol
40003500-
3000-
00 2500.c55
a)
1500-
1000,
5000
1
5.0
10
-I
I
T
15
20
2-Theta(deg)
15
20
2-Theta(deg)
1
I-
1
I
25
30
25
30
Dayton Malpass <2um Mg-Glycol
(b)
40003500-
3000= 2500-
0
2000
a)
z 15001000-
500-
I
5.0
I
10
170
probably developed from interfingered claystone and tuffaceous beds of
the Spencer Formation.
The truncated paleosol of the study site and higher surface
could have been displaced by mass wasting caused by faulting
disturbances and/or seismic activity before the late Pleistocene
glacier-outburst floods. Glasmann and Kling (1980) found, based on
electron micrographs of quartz-sand grains, that the paleosol is highly
erodable and that much of the material of the Greenback in elevations
above 80 m may be locally derived from the paleosol and saprolite of
the Spencer Formation. On et al. (1992) summarized the likely events
that took place during the valley's history. Renewed local uplifting,
faulting, and folding occurred during the Pliocene epoch as major folds
of the Coast Range block formed from the subduction of the Juan de
Fuca plate beneath the North American plate. Two local "normal
faults" that are due to folding and flexing of rocks from crustal
extension and stretching are the Kings Valley and the Corvallis faults.
Both faults run northeast by southwest and are located to the west
and northwest of Corvallis (Fig 6.13). In addition, the Calapooia fault
runs to the northeast of Corvallis and the Owl Creek fault to the east.
The faults show movement into the Pleistocene time. Periods of rapid
subsidence during this time would have caused catastrophic
earthquakes. Evidence of large-scale seismic activity as late as the
Holocene period has been discovered in buried coastal swamps.
Later, during the series of Pleistocene floods, high-energy
floodwaters with hydraulic surging and ebbing could have completely
reworked the homogenized colluvium. The shoreline (Site 1) was left
striped down to the sandstone and the clayey colluvium settled with
the distinct tapering at its uppermost limits. Presumably this series of
events occurred during two or more episodes of instability to create the
171
Figure 6.13. Willamette Valley faults (from Orr et al, 1992).
oc,
2G
Nytk.
le
6
Hillsboro
X
Pt, AN.
X.,\C"I''
?
Lake 0..0
\?4
C.4.4mt
':Inumin.win.
Portland
*Beaverton
P
wivartiette basin
IAN
ottlNe.
-
\trt Woodburn
Silverton
s)
WC,
172
lower olive clay horizons and the upper gray clay horizon before the
final flooding phase that deposited the Greenback Member. This
would account for the occurrence of higher mica content in the upper
gray clay horizon than in the lower olive clay horizons.
It could be postulated that the olive clay layers were reworked by
the fluctuating shoreline of the flood event that deposited the Irish
Bend sediments. Following this deposition, a period of stability
ensued that led to the formation of an argillic horizon in the Irish Bend
Member that later was partially truncated by additional flood events
(Parsons et al., 1968; Balster and Parsons, 1969). This period of
stability followed by subsequent flood events may also account for the
less ordered mica in the olive clays than in the gray clay and the clay
films found in the lower olive clay horizons (3Bsstyl and 3Bssty2) but
not in the upper olive clay horizons.
Yet another flood, perhaps the one that was responsible or partly
responsible for deposition of the Malpass Member, could have
reworked colluvial or side-valley alluvial material that had eroded
between flooding events resulting in the gray clay layer (2Bt1 and 2Bt)
at Sites 2 and 3.
However, this scenario would place fluctuating lake heights
between 96 and 98 m in absolute elevation, which is higher in
elevation than found by Glasmann (1979). The author found almost
complete erosion of the Spencer paleosol between 80 and 86 m (Lower
Brateng surface), presumably by lakeshore erosion processes when the
Irish Bend Member was deposited, and very little erosion of the
paleosol above 86 m (Upper Brateng surface).
173
Summary
Landscape and soil development has been from a complex
sequence of local and regional processes. The results of the
investigation support the presence of four distinct stratigraphic units
and suggest that the clay horizons are colluvial material from the
eroded bedrock of the Spencer Formation. Speculation was made
about mass-wasting of the paleosol associated with the formation an
about the tapering of the two clay units on the hillslope from
fluctuating shorelines of lakes created during the many Missoula Flood
events.
Further analysis to look at quartz-sand grain morphology
(Glasmann and Kling, 1980) with scanning electron microscopy (SEM)
would be needed to confirm local and transported mineralogy and
grain characteristics. In addition, radiocarbon dating and the isotopic
018 signature would aid in finding the age of the soil materials and
identifying the source (Birkeland, 1984)
174
Chapter 7
SUMMARY AND CONCLUSION
The soil morphology of Site 1 suggests a mostly aerobic
environment within the upper 65 cm. High chromas and few iron
redox features indicate very short periods of saturation and reductive
conditions. The soil morphology of Sites 2, 3, and 4 suggests episodic
saturation and anaerobic and iron reducing environments that lasts
for extensive periods of time. Redoximorphic concentrations within
7cm of the soil surface in soils of Pits 2 and 3 and concentrations at
the surface in soils of Pit 4 indicate that iron and manganese are being
reduced and oxidized high within the soil profile. Zones of depletion
over clay horizons in Pits 2 and 3 and evidence of a discontinuity
suggest that clays are restricting vertical water movement and creating
a seasonal perched water table.
The hydrologic data and redox data correlated well with the
morphological properties for each of the four pedons. Short one-week
episodic saturation events that averaged around 16 cm beneath the
surface of Site 1 soils correspond to the occurrence of iron concretions
less than 0.5 mm in diameter. Mean seasonal water table levels for
Sites 2 and 3 (12.6 cm and 9.8 cm respectively) corresponded to
horizons that had at least 30% high value and low chroma (4/2)
matrix colors and many distinct iron masses. The near surface mean
seasonal water table in the soils of Site 4 is associated with oxidized
rhizospheres found at the surface and many distinct iron masses
found at 6 cm beneath the soil surface.
The hydrologic, redox potential, and soil temperature data
provide documentation that the soils of Sites 2, 3, and 4 meet the
conditions in the hydric soil definition for "saturated, flooded, or
ponded long enough during the growing season to develop anaerobic
175
conditions in the upper part." Hydrologic data indicate that water
tables remained fairly stable and soils stayed saturated high in the soil
profiles for a majority of the wet season (October June) at Sites 2, 3,
and 4. The data show that the soils were continuously saturated at
some depth within 30 cm from the soil surface for 19-20 weeks at Site
2, 19-24 weeks at Site 3, and 23-25 weeks at Site 4. The growing
season had no bearing on the time of saturation since biological zero
(5°C at 50 cm) was never reached.
Hydrologic data indicate that the hydrologic regime on the upper
footslope of Witham Hill is the result of seasonal perched water tables
and episaturation as the result of a discontinuity consisting of slowly
permeable clays. On the lower footslope, Site 4 hydrologic data
suggest temporary episaturation that gives way to endosaturation.
This hydrologic regime is believed to be the result of alluvial deposition
of clays on a lower drainage landscape.
Reduction-oxidation potentials indicate varying reducing
environments within the upper 30 cm at Sites 2, 3, and 4.
Anaerobiosis began in November and December between two weeks
before to two weeks after the onset of continuous saturation at all the
sites. Soils at Site 2 had the lowest mean water table (12.6) and the
longest lag time between continuous saturation and the onset of
anaerobiosis and iron reduction, whereas Site 4 soils had the highest
mean water table (5.5 cm) and the shortest lag time. Extended periods
of iron reduction occurred three to four weeks after onset of
continuous saturation at Site 2, after one week at Site 3, and from two
weeks before to one week after at Site 4. Reduction continued for 21 to
30 weeks into the month of May at Sites 2 and 3 and into June at Site
4.
Although morphological properties generally concurred with
hydrologic and redox potential data, Site 2 and Site 3 morphological
176
characteristics did not correspond with any of the fourteen applicable
indicators in the Field Indicators of Hydric Soils in the U.S., Version 3.2.
Commonly accepted factors known to affect the development or
visibility of characteristic morphologies (parent materials that are
reddish or grayish; dark soils; soils with high pH or low organic matter
content; low soil temperatures; and aerated groundwater) were not
factors in the study site soils.
In addition, the soils of Site 2 came closer to meeting some
indicator criteria than did Site 3 soils, even though the soils of Site 2
had a lower mean seasonal water table (12.5 cm versus 9.8 cm);
shorter duration of saturation (19 and 20 weeks versus 19 and 24
weeks); and shorter duration of iron reduction (21 and 23 weeks
versus 24 and 25 weeks). Site 2 soils failed one indicator only because
the matrix was 3+/2 versus the specified 3/2. The two major factors
that prevented positive outcomes for soils of Sites 2 and 3 were the
inability to round colors that fell between color chips and layer
thickness requirements. A third factor was the requirement that at
least 60% of a designated layer have a depleted matrix.
The Witham Hill wet soil study site was visited in July 1997 by a
group from the national Wet Soils Monitoring Project, members of the
National Technical Committee for Hydric Soils, and members of the
Field Indicator Committee. The field trip resulted in a change to the
F3 Depleted Matrix indicator to incorporate the morphological
characteristic of soils at Site 3. The additional specification, which
decreases the layer thickness requirement under certain conditions, is
in the Field Indicators of Hydric Soils in the United States, Version 4
issued in March 1998.
The discussion during the field trip about the Site 2 soils did not
evolve beyond soil color notation. A majority of the group felt that the
matrix color of the A3 horizon at Site 2 was 3/2 versus the 3+/2
177
originally noted. The differences in opinions about the "correct"
Munsell color highlight the problem of trying to be exact with a
qualitative parameter that is affected by many factors, not the least of
which is personal judgement. Version 4 addresses the problem of soil
notation by changing the way colors that fall between Munsell color
chips are applied. Values can now be rounded to the nearest color
chip but chromas cannot. The change enables the A3 horizon at Site 2
with the debated 3+/2 matrix color to meet the F6 indicator that
required a _.3/2 matrix. However, it is believed that further
consideration should be given to rounding not only value but also
chroma.
The B/E and E/B horizons of Pits 2 and 3 present a case for
either reviewing the requirement that a depleted matrix make up 60%
of a horizon for many indicators or consider developing a new regional
indicator to cover the observed morphology. Other factors besides
duration of saturation and reduction may need to be investigated.
There may be physical properties or chemical processes that influence
redistribution or iron without removal and/or net loss of iron from a
horizon, as.was the situation at the study site. The B/E and E/B
horizons located directly over the perching clay horizons had iron
reduction occurring from 21 to 25 weeks per wet season but had iron
oxide (Fed) contents that indicated no net loss of Fe (II) iron by
translocation out of the horizons.
Once the soils of Sites 2, 3, and 4 were determined to be hydric
soils, two questions important to land management surfaced were
apparent: (1) are areas of the study site wetlands and (2) what
conditions and events resulted in the hydrologic regime on the
hillslope.
Wetlands have three essential characteristics and criteria:
wetland hydrology, hydric soils, and hydrophytic vegetation. Review of
178
the criterion for wetland hydrology and hydrophytic vegetation resulted
in confirmation of wetland characteristics at Sites 2, 3, and 4 based on
saturation within the 30 cm of the soil surface and the 50%
dominance measure. The hydrophytic vegetation criterion was
satisfied at Sites 2 and 3 by plant communities that are dominated by
more than 50 percent facultative FAC species and at Site 4 by
communities that are dominated by more than 50 percent FACW
species.
Geomorphic processes that resulted in the present hydrologic
conditions on the hillslope were investigated by examining past
research on Willamette Valley geomorphic surfaces and geologic
history, and by performing mineralogical analyses on the study site
soils. Mineralogical properties of the surface horizon, clay horizons,
and weathered bedrock were investigated to identify stratigraphic
units and possible sources of material origin.
The results of the mineralogical analysis support the presence of
four distinct stratigraphic units on the upper transect with the upper
unit identified as the Greenback Member of the Willamette Formation.
The geomorphic surface of the upper transect at the study site is
believed to be the Upper Brateng over the Spencer Sandstone
Formation. The paleosol that is usually associated with the Upper
Brateng is believed to have been removed by catastrophic local events.
The lower transect is a poorly drained soil on a younger alluvial
Ingram surface created by drainageway incision and deposition on
older surfaces.
Mineral analysis suggests that the two clay units and the
sandstone at the study site share a common origin. However,
morphological characteristics of the clay horizons and mineralogical
differences indicate that the clay horizons are not residual, and a
discontinuity exists between the lower clay unit and the sandstone.
179
The >2 i.tm vermiculite and mica in the clay units indicate local
slope-related transport. The clay horizons are thought to be colluvial
material from erosion of interfingered clayey beds and tuffaceous beds
of the Spencer Formation sandstones after the paleosol had been
removed. Speculation was made about mass wasting of the paleosol
and about the tapering of the two clay units. Mass wasting caused by
faulting disturbances and/or seismic activity could have displaced the
paleosol and once higher surface of the study site. Late Pleistocene
glacier-outburst floods could have reworked the colluvial fill on the
footslope to form the clay units.
If these factors and events can be considered a reasonable
speculation, many regional and localized components and conditions
came together to create the complex geomorphology, landscape, and
soils of the study area.
180
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McLean, E.O. 1982. Soil pH and lime requirements. p. 199-224. In
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186
National Research Council. 1995. Wetlands: Characteristics and
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5:35-70.
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187
Reckendorf, F. 1993. Geomorphology, stratigraphy, and soil
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192
APPENDICES
193
Appendix A
NSSL Soil Characterization Data
***
S960R-003-001
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY, OREGON
***
PRINT DATE 07/23/97
; FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
FINE-SILTY, MIXED, SUPERACTIVE, MESIC ULTIC HAPLOXEROLL
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
NATIONAL SOIL SURVEY CENTER
- PEDON
96P 347, SAMPLES 96P 2696- 2702
- GENERAL METHODS 1B1A, 2A1, 28
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SAMPLED AS
REVISED TO
.
-1--
SAMPLE
;
.
DEPTH
-2--
HORIZON
(CM)
NO.
07
96P2696S
7- 19
96P2697S
19- 46
96P26988
96P2699S 46- 65
96P2700S 65- 95
96P2701$ 95-130
96P2702S 130-155
A2
A3
BA
Bwl
Bw2
2Cr/Bt
ORGN TOTAL
C
N
6Alc
PCT
(CM)
7
7- 19
19- 46
46- 65
65- 95
95-130
130-155
6B4a
<2MM
-4--
-6--
-7--
-8--
-9--
-10-
-11-
-12-
-13-
-14-
48.2
48.3
47.4
48.3
47.7
52.9
52.9
24.0
23.5
22.2
22.2
23.2
15.0
5.9
9.0
9.1
9.6
8.9
8.2
8.5
15.5
32.5
33.0
32.6
33.4
32.7
39.9
43.1
15.7
15.3
14.8
14.9
15.0
13.0
9.8
10.2
9.6
9.3
9.2
10.2
7.6
2.7
9.7
9.9
9.4
9.3
9.4
5.8
2.3
3.7
3.6
3.4
3.3
3.2
1.3
0.8
0.3
0.3
0.1
0.3
0.2
0.3
0.1
-15-
-16-
-W-
-18-
-19-
-20-
- -)(-COARSE FRACTIONS(MM)-)(>2MM)
- - - - WEIGHT - - - WT
1
2
5
20
.1- PCT OF
-2
-5
-20
-75
75 WHOLE
>
<- PCT OF <75MM(3B1)->
SOIL
VC
0.1
--
14
14
0.1 --TR
--
TR --13
0.1
--13 --TR
TR --7 --
0.2
3
TR
--
1
17
5
3
--
EXTR TOTAL (- - DITH-CIT - -)(RATIO/CLAY)(ATTERBERG )(- BULK DENSITY -) COLE (- - -WATER CONTENT - -) WRD
P
S
EXTRACTABLE
15
- LIMITS - FIELD 1/3 OVEN WHOLE FIELD 1/10
1/3
15
WHOLE
FE
AL
MN
CEC
BAR
LL
PI
MOIST BAR DRY
SOIL MOIST
BAR
BAR
BAR SOIL
6S3b 6R3c
6C2b 6G7a 602a
8D1
801
4F1
4F
4A5
4Ald 4Alh 401
484
4B1c 481c
482a 4C1
PPM <- PERCENT OF <2MM -->
PCT <0.4MM <- - Gicc - - -> CM/CM <- - -PCT OF <2MM - -> CM/CM
2.6
2.6
2.6
2.6
2.7
2.5
3.1
3.37
2.08
1.27
0.64
0.42
0.26
0.10
AVERAGES,
-5--
(- - -TOTAL - - -)(- -CLAY- -)(- -SJLT- -)(- - - - - -SAND- - CO3 FINE COARSE
VF
F
CLAY SILT SAND FINE
M
C
LT
.002
.05
LT
LT
.002
.02
.05
.10
.25
.5
.002
-.02 -.05 -.10 -.25
-.50
-1
-.05
-2
.0002
.002
<
PCT OF <2MM
(3A1)
27.8
28.2
30.4
29.5
29.1
32.1
41.2
Al
DEPTH
0-
-3--
DEPTH
25-100:
0.2
0.2
0.2
0.2
0.2
0.2
0.2
PCT CLAY
30
TR
TR
TR
TR
TR
0.89
0.84
0.77
0.75
0.81
---
1.28
1.08
PCT
0.46
0.45
0.42
0.46
0.48
0.75
0.82
.1-75MM
1.27
1.28
1.33
1.35
1.39
1.12
1.16
14
1.45
1.44
1.49
1.54
1.54
1.43
1.46
0.045
0.040
0.039
0.045
0.034
0.085
0.080
30.5
27.5
27.7
27.3
26.5
45.0
39.6
12.7
12.6
12.8
13.5
14.1
24.0
33.7
0.23
0.19
0.20
0.19
0.17
0.24
0.07
***
PRIMARY CHARACTERIZATION DATA
***
PRINT DATE 07/23/97
S960R-003-001
;
FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
SAMPLED AS
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 347, SAMPLE 96P 2696- 2702
:
-13-
(- NH4OAC EXTRACTABLE BASES -) ACID- EXTR (- - - -CEC
DEPTH
(CM)
CA
5B5a
6N2e
MG
5B5a
602d
NA
5B5a
6P2b
<
0-
7
7- 19
19- 46
46- 65
65- 95
95-130
130-155
8.5
8.6
8.2
8.7
9.0
17.5
19.4
ANALYSES:
4.2
4.7
5.2
6.3
6.6
13.2
14.8
0.1
TR
0.3
0.1
0.1
0.2
0.3
ITY
AL
K
SUM
5B5a BASES
642b
6H5a 6G9c
MEG / 100 G
0.8
0.5
0.4
0.4
0.3
0.6
13.6
13.8
14.1
15.5
16.0
31.5
1.0
35.5
16.9
14.2
13.0
11.4
10.6
13.6
11.7
S= ALL ON SIEVED <2mm BASIS
SUM
CATS
5A3a
NH4OAC
5A8c
-
->
30.5
28.0
27.1
26.9
26.6
45.1
47.2
24.8
23.6
23.3
22.1
23.6
41.2
44.6
AL
SAT
- -)
BASES
+ AL
5A3b
5G1
-14-
-15-
-BASE SAT- CO3 AS RES.
SUM
NH4 CAC03 OHMS
OAC <2MM
/CM
6E1g 8E1
5C3
5C1
PCT -
<
45
49
52
58
60
70
75
55
58
61
70
68
76
80
-16-
-17-
-18-
COND.(MMHOS
/CM
81
-19-
- -PH - - -)
CACL2 H2O
.01M
801f
1:2
->
0.07
0.02
--
0,01
0.02
-20-
5.2
5.4
4.7
5.3
4.6
5.8
5.2
8C1f
1:1
6.9
7.0
7.0
7.1
7.2
7.8
5.6
***
S960R-003-001
SAMPLED AS
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY, OREGON
;
:
PRINT DATE 07/23/97
FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
PEDON
96P 347, SAMPLES 96P 2696- 2702
- GENERAL METHODS 1B1A, 241, 2B
-1--
-2--
-3--
-4--
ACID OXALATE EXTRACTION
SAMPLE
NO.
96P2696
96P2697
96P2698
96P2699
96P2700
96P2701
96P2702
HZ
NO
1
2
3
4
5
6
7
OPT
DEN
8J
0.07
0.07
0.05
0.03
0.04
0.02
0.02
FE
SI
AL
6C9b
6V2b 6012b
0.29
0.29
0.27
0.22
0.26
0.30
0.35
0.11
0.10
0.11
0.10
0.10
0.14
0.17
-5--
-6--
PHOSPHOUS
CITACID
6S5
RET
654b
-7-KCL
MN
6D3b
-8--
TOTAL
C
6A2e
<- P C T of< 2mm-><-PPM -><
0.23
0.23
0.22
0.17
0.17
0.20
0.26
***
-9--
-W-
-W-
-13-
-14-
-15-
-16-
-W-
-18-
-19-
-20-
(- -WATER
CONTENT- - )(- - WATER DISPERSIBLE - - - MIN
AGGRT
0.06
15
12<- - PIPETTE - - >< - HYDROMETER - > SOIL STABL
BAR
BAR
BAR
BAR CLAY SILT SAND
CLAY SILT SAND
CONT <5mm
4B1c
4Bla 4Bla
4B2b <- - - 3Alc - - -><- - - SML - - -> 8F1
401
< 2 m m
>< POT>
)
PERCENT of
24.0
22.4
21.7
22.9
22.7
35.7
50.5
PRIMARY CHARACTERIZATION DATA
***
S960R-003-001
SAMPLED AS
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY
PRINT DATE 07/23/97
FINE-LOAMY, MIXED, MES1C TYPIC XERUMBREPT
PEDON 96P 347, SAMPLE 96P 2696- 2702
;
;
-12-
-15-
-16-
-17-
-18-
K20
><
Na20 <
-20-
-19-
>
.
FRACT <
ION <
NUMBER
<- - ><
<
TCLY
TCLY
TCLY
><
X-RAY
SAMPLE
7A21
- peak size
MT 2
MT 3
MT 3
QZ 2
QZ 2
KK 2
KK 2
KK 2
MI
1
MI
----- - -><
><
-> EGME
> REIN
>
702
FD
SAMPLE
ION <
<
-><
><
- 7A21 - - - - ><
SMEC
SMEC
SMEC
NUMBER
< - -><
Peak Size - - -><
1
SAND
SILT MINERALOGY (2.0-0.002mm)
-><
OPTICAL
THERMAL
DTA - ->< - TGA - ->TOT RE<
GRAIN COUNT
><
7A3c - >< - 7A4c
7B1a
- - Percent - - - -><
Percent
X-RAY
CSI
CSI
CSI
CSI
CS1
CSI
QZ43
OP 3
HNtr
QZ50
BT 4
BYtr
QZ34
BT 2
BYtr
50
61
CSI
46
CSI
CSI
FK29
PR 2
BYtr
FK20
OW 2
ZRtr
FK24
OP
1
CAtr
FP 7
OW 2
GNtr
MS 7
CD 1
GNtr
OW16
CD 1
HNtr
MS 6
ZRtr
CAtr
FP 6
PR
1
RUtr
FE 9
GN 1
ZRtr
>
> INTER
> PRETA
>
TION
><
->
><
><
><
><
BT 5
POtr
ZEtr
FE 5
ZEtr
POtr
MS 6
PR 1
ZEtr
FE 4
CDtr
RUtr
OP 5
HNtr
CLtr
FP 4
POtr
MZtr
FRACTION INTERPRETATION:
TCLY
Total Clay, <0.002mm
Coarse Slit, 0.02-0.05mm
CS1
MINERAL INTERPRETATION:
MT
MS
ZR
CA
montmorillon
muscovite
zircon
calcite
RELATIVE PEAK SIZE:
KK
BT
PO
ZE
kaolinite
biotite
plant opal
zeolite
5 Very Large
INTERPRETATION (BY HORIZON):
SMEC = Smectlte
PEDON MINERALOGY
BASED ON SAND/SILT; MIXED
BASED ON CLAY: SMECTITIC
FAMILY MINERALOGY:
MIXED
COMMENTS:
4 Large
INTER
PRETA
TION
- > <mg /g>< - ->
2
MI 2
QZ 1
<
FRACT <
96P2698
96P2698
96P2698
96P2700
96P2700
96P2700
96P2702
96P2702
96P2702
-14-
-13-
CLAY MINERALOGY ( <.002mm)
-><
THERMAL
ELEMENTAL
>< - DTA - ->< - TGA - -> 5102 AL203 Fe203 Mg0
Ca0
><
7A4c
7C4a- ><
7A6b
> <
->< - - - Percent
Percent
<
96P2698
96P2700
96P2702
***
QZ
FE
CD
RU
quartz
iron oxides
chalcedony
rutile
3 Medium
2 Small
MI
OP
HN
CL
mica
opaques
hornblende
chlorite
1 Very Small
FK
PR
potas feldsp
pyroxene
BY
FD
beryl
feldspar
6 No Peaks
FP
OW
GN
MZ
plag-feldspa
oth-weath mn
garnet
monazite
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY, OREGON
S960R -003 -002
***
PRINT DATE 07/23/97
; FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
FINE, SMECTICTIC, MESIC VERTIC PALEXERALF
;
SAMPLED AS
REVISED TO
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
96P 348, SAMPLES 96P 2703- 2713
- PEDON
- GENERAL METHODS 1B1A, 2A1, 2B
-7--
SAMPLE
DEPTH
HORIZON
(CM)
NO,
ORGN TOTAL
C
N
DEPTH
6Alc
PCT
(CM)
0-
7
7- 14
14- 27
27- 36
36- 50
50- 70
70- 92
92-109
109-140
142-155
153-170
6B4a
<2MM
-10-
-11-
-12-
-13-
52.7
50.7
49.2
48.7
48.1
47.9
35.2
30.2
30.2
43.8
36.3
22.3
22.8
22.3
20.1
20.5
19.2
8.8
11.6
12.5
28.5
28.8
34.9
34.9
33.9
33.9
34.3
35.2
27.7
23,3
22,1
25.0
25.3
9.3
9.6
9.8
10.8
10.1
11.1
34.4
35.9
36.0
16.3
18.8
17.8
15.8
15.3
14.8
13.8
12.7
7.5
6.9
8.1
18.8
11.0
8.6
9.7
9.1
8.5
8.3
8.2
4.0
5.0
5.0
19.6
11.9
9.9
9.2
9.2
8.2
8.4
7.6
3.5
4.1
5.0
6.9
12.8
-14-
-
C
.5
-1
3.5
3.4
3.4
3.1
3.3
2.9
1.2
0.2
0.3
0.5
0.3
0.4
0.4
1.4
1.6
1.5
0.5
0.3
0.5
0.3
3.8
0.1
-15-
-16-
-17-
-18-
-19-
-20-
- - -)(-COARSE FRACTIONS(MM)-)(>2MM)
VC
- - - - WEIGHT - - - WT
1
2
5
20
.1- PCT OF
-2
-5
-20
-75
75
WHOLE
>
<- PCT OF <75MM(3B1) -> SOIL
0.1
0.2
0.1
TR
0.1
0.1
TR
0.6
0.6
TR
--
-----------
14
13
13
12
12
11
5
7
9
17
------------
EXTR TOTAL (- - DITH-CIT - -)(RATIO/CLAY)(ATTERBERG )(- BULK DENSITY -) COLE (- - -WATER CONTENT - -) WRD
P
EXTRACTABLE
15
- LIMITS - FIELD
1/3 OVEN WHOLE FIELD
1/10
S
1/3
15
WHOLE
FE
AL
MN
CEC
BAR
LL
PI
MOIST BAR DRY
SOIL MOIST
BAR
BAR
BAR SOIL
6S3b 6R3c 6C2b 6G7a 6D2a
801
8D1
4F1
4F
4A5
4Ald 4Alb 4D1
484
481c 4B1c
4B2a 4C1
PCT <0.4MM <- - G /CC - - -> CM/CM <- - -PCT OF <2MM - -> CM/CM
PPM <- PERCENT OF <2MM -->
2.2
2.7
2.6
2.9
2.9
2.9
2.6
2.8
2.9
4.8
0.9
5.58
2.93
1.45
1,13
0.67
0.61
0.27
0.20
0.16
0.09
0.05
AVERAGES,
-9--
(- - -TOTAL - - -)(- -CLAY- -)(- -SILT- -)(- - - - - -SANDF
M
FINE
CO3 FINE COARSE VF
CLAY SILT SAND
LT
.002
.02
.05
.10
.25
LT
.002
.05
LT
-.25 -.50
-.05
-2
.0002
.002 -.02 -.05 -.10
.002
(3A1)
PCT OF <2MM
<
25.0
26.5
28.5
31.2
31.4
32.9
56.0
58.2
57.3
27.7
34.9
Al
0- 7
96P2703S
A2
7- 14
96P2704S
A3
96P2705S 14- 27
AE
96P2706S 27- 36
El
96P2707S 36- 50
E2
96P2708S 50- 70
96P27095 70- 92 '28ssb
96P2710S 92-109 3Bssbl
96P2711S 109-140 3Bssb2
96P2712S 142-155 4C
96P2713S 153-170 4Bg
-8--
DEPTH
25-100:
0.2
0.2
0.3
0.3
0.2
0.3
0.2
0.2
0.3
0.2
0.1
PCT CLAY
0.1
TR
TR
TR
TR
TR
42
1.05
----
0.84
0.72
0.66
0.63
0.64
0.62
0.66
0.65
TR
TR
1.46
1.03
PCT
1.02
1.18
1.32
1.37
1.46
1.51
1.28
1.25
1.20
0.60
0.50
0.43
0.40
0.40
0.44
0.45
0.46
0.46
0.86
0.66
.1-75MM
9
1.17
1.31
1.42
1.48
1.58
1.62
1.94
1.93
1.90
0.047
0.035
0.025
0.026
0.027
0.024
0.149
0.156
0.166
35.6
29.1
27.8
25.7
24.2
23.7
38.4
40.6
43.3
15.0
13.2
12.2
12.6
12.6
14.4
25.0
26.6
26.6
23.7
23.0
0.21
0.19
8.21
0.18
0.17
0.14
0.17
0.18
0.20
PRIMARY CHARACTERIZATION DATA
***
S960R-003-002
SAMPLED AS
;.FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 348, SAMPLE 96P 2703- 2713
-1--
(CM)
7
71427365070-
14
27
36
50
70
92
-3--
-4--
-5--
-6--
-7--
-10-
-11SAR
<- - - - - ---- -MEG / 100 G
(- -CEC-) EXCH
NH4SUM
NA
CATS
OAC
5A3a 5A8c
502
>
PCT
8.0
7.1
6.3
6.5
6.8
7.4
13.9
16.0
16.8
16.1
18.2
3.7
3.4
3.7
4.1
4.7
5.1
10.5
12,2
12.5
11.2
13.2
32.4
29.4
26.2
26.3
25.0
25.9
41.5
42.3
41.4
38.2
40.1
CA
MG
NA
681b
601b
6Plb
(- NH4OAC EXTRACTABLE BASES -) ACIDCA
MG
NA
K
SUM
ITY
585a 5B5a
D85a 585a BASES
682e 602d 6P2b 6Q2b
6H5a
DEPTH
0-
-2--
92-109
109-140
142-155
153-170
0.1
---TR
0.1
0.5
0.6
0.6
0.5
0.6
0.4
0.4
0.3
0.3
0.2
0.4
0.5
0.5
0.6
0.4
0.4
12.2
10.9
10.3
10.9
11.7
13.0
25.4
29,3
30.5
28.2
32,4
20.2
18.5
15.9
15.4
13.3
12.9
16.1
13.0
10.9
10.0
7.7
-8--
-9--
26.2
22.3
20.4
20.6
19.9
21.0
34.9
38.6
37.1
40.5
36.0
K
CO3
HCO3
F
CL
1
50
1
1
1
2
SO4
NO2
6Lld
6W1b
DEPTH
601b
<
0-
38
37
39
41
47
1
-14-
611b
6J1b
6U1b
MEQ / LITER
6K1d
-16-
-17-
61
69
74
74
81
-18-
4.4
)PRED.
TOTAL ELEC. ELEC.
H2O
SALTS COND. CORO.
EST.
8A3a
81
6M1d
8A
805 MMHOS MMHOS
> <- -PCT- ->
/cm
/cm
NO3
7
0.13
0.03
----
1.9
1.5
1.8
1.2
0.1
TR
3.9
3.4
0.1 105.5
MMHOS/CM OF 1:2 WATER EXTRACT (81) & EXCH NA AS EXTRACTABLE NA FOR LAYERS
ANALYSES:
S= ALL ON SIEVED <2mm BASIS
TR
1,
2,
0.76
3,
0.01
0.21
0,23
0.27
0.19
0.11
4,
5,
-19-
CASO4 AS
(- - - -PH GYPSUM
SAT CACL2
<2MM <20MM PASTE .01M
6F1a 6F4
8C1b
8Clf
<- -PCT ->
1:2
47
49
50
53
59
62
73
76
82
70
90
7- 14
14- 27
27- 36
36- 50
50- 70
70- 92
92-109
109-140
142-155
153-170
-15-
BASE
CARBONATE
SATURATION
AS CAC03
SUM NH4OAC <2MM <20MM
5C3
5C1
6E1g
8E1
<- -PCT- > <- -PCT ->
TR
TR
TR
TR
TR
2
-13-
-12-
WATER EXTRACTED FROM SATURATED PASTE
(
(CM)
5E
PRINT DATE 07/23/97
6,
7,
8,
10,
11,
4.9
4.9
5.0
4.7
4.5
4.8
4.1
4.2
4.3
4.8
5.0
-20-
- -)
H2O
8C1f
1:1
7.1
7.1
7.0
6.3
6.9
6.0
4.7
6.4
4.8
7.4
7.0
'fee
S960R-003-002
SAMPLED AS
P R
!
M A R Y
C H A R A C T E R
(BENTON COUNTY, OREGON
I
Z A T
I
O N
SAMPLE
NO.
HZ
NO
-2- -3- -4-
-6-
ACID OXALATE EXTRACTION
PHOSPHOUS
GITRET
ACID
6S4b 6S5
96P2703 1
96P2704 2
96P2705 3
96P2706 4
96P2707 5
96P2708 6
96P2709 7
96P2710 8
96P2711 9
96P2712 10
96P2713 11
8J
0.11
0.10
0.09
0.07
0.05
0.05
0,02
0.02
0.01
0.02
0.01
PRINT DATE 07/23/97
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
- PEDON
96P 348, SAMPLES 96P 2703- 2713
- GENERAL METHODS 101A, 2A1, 2B
OPT
DEN
eee
)
; FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
.
-1--
DATA
FE
SI
6C9b
6V2b 6G12b
0.78
0.87
0.72
0.59
0.48
0.52
0.24
0.14
0.10
0.31
0.04
0.11
0.12
0.08
0.13
0.11
0.12
0.14
0.13
0.04
0.16
0.09
AL
-8--
-7--
KCL
TOTAL
MN
603b
C
6A2e
<- P C T of< 2mm-><-PPM -><
0.20
0.22
0.23
0.23
0.18
0.21
0.19
0.15
0.14
0.16
0.11
-9-
-10-
-11-
-n-
-14-
-15-
-u-
-2o-
(- -WATER CONTENT- - )(- - - - WATER DISPERSIBLE - - - - ) MIN
AGGRT
15
0.06
12<- - PIPETTE - - >< - HYDROMETER - > SOIL STABL
BAR
BAR
BAR
BAR CLAY SILT SAND CLAY
SILT SAND
CONT <5mm
481c 4Bla 4B1a 4B2b <- - - 3Alc - - -><- - - SML - - -> 8F1
4G1
< 2 m m
>< PCT>
PERCENT of
25.5
22.6
20.8
20.7
20.7
27.5
35.0
36.9
36.9
35.1
32.6
***
PR IMARY CHARACTER I ZATI ON
S960R-003-002
SAMPLED AS
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ;
;
<
FRACT <
ION <
NUMBER
<- - >< -
<
96P2705
96P2708
96P2709
96P2711
96P2712
96P2713
SAMPLE
TCLY
TCLY
TCLY
TCLY
TCLY
TCLY
FRACT <
ION <
MT
MT
MT
MT
X-RAY
><
7A2I
><
><
><
- peak size
KK 2
KK 2
4
4
3
4
MM
MT
KK
KK
KK
KK
2
2
3
2
2
2
MI
MM
VR
QZ
KH
KH
NUMBER
< - -><
CSi
CSI
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
MT 2
QZ 2
MI 2
PRINT DATE 07/23/97
-13-
-14-
-15-
CLAY MINERALOGY (<.002mm)
-><
THERMAL
ELEMENTAL
DTA - ->< - TGA - -> SI02 AL203 Fe203 Mg0
Ca0
7A6b
><
7A4c
><
7C4a- -><
Percent
Percent
-16-
-17-
K20
><
Na20 <
-18-
-19>
----- - -><
><
-> EGME
INTER
> RETN PRETA
>
TION
7D2
-><mg/g>< - ->
QZ 2
MI
2
QZ
1
SMEC
SMEC
SMEC
SMEC
SMEC
QZ 1
QZ 1
- - X-RAY - - -><
- 7A21 -
96P2705
96P2705
96P2705
96P2705
96P2708
96P2708
96P2708
96P2708
96P2709
96P2709
96P2709
96P2709
96P2711
96P2711
96P2711
96P2711
96P2712
96P2712
96P2712
96P2712
2
2
2
1
1
2
***
FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
PEDON 96P 348, SAMPLE 96P 2703- 2713
-12-
SAMPLE
DATA
-
><
- ><
Peak Size- - -><
SAND
SILT MINERALOGY (2.0-0.002mm)
- - THERMAL - - - ->< - - - - - - - OPTICAL
DTA - ->< - TGA - ->T0T RE<
GRAIN COUNT
><
7A3c - >< - 7A4c
781a
- - Percent
Percent
54
57
55
54
58
QZ45
OP 3
HNtr
GCtr
QZ47
OW 2
RUtr
CAtr
QZ45
CD 3
POtr
RUtr
QZ45
PR 2
GNtr
TMtr
QZ43
BT 2
RUtr
TMtr
><
><
><
><
FK25
OW 2
BYtr
TEtr
FK24
DT 2
ZEtr
GStr
FK29
BT 1
ZEtr
CLtr
FK31
CD 1
ZRtr
MS 8
CD 2
ZRtr
TMtr
MS 6
PR 2
POtr
FP 6
FE 3
PO
PR
MS 6
FZ 1
BYtr
TMtr
FP 7
OW 1
POtr
FP 4
FK26
CD 1
GNtr
CLtr
BT 3
GNtr
GStr
FP 5
BYtr
GNtr
OP 4
CDtr
ZRtr
FE 4
OW 1
GNtr
OP 3
HN 1
GStr
FE 5
BT 1
ZEtr
MS 3
HNtr
CLtr
OP 3
BYtr
RUtr
FE14
FP 6
PR
HN
MS 4
OPtr
CLtr
OW 3
ZRtr
CAtr
1
BYtr
1
ZEtr
RUtr
FE 6
HN
1
TMtr
1
POtr
1
PR
1
ZRtr
>
>
>
>c
INTER
PRETA
TION
->
***
PRIMARY CHARACTERIZATION DATA
S960R-003-002
SAMPLED AS
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY
-1--
-2--
-3--
-4--
***
PRINT DATE 07/23/97
;
;
FINE-LOAMY, MIXED, MESIC TYPIC XERUMBREPT
PEDON 96P 348, SAMPLE 96P 2703- 2713
-5--
-6--
-9--
-n-
-6--
-7--
CSI
Coarse Silt, 0.02-0.05mm
-10-
-14-
-15-
-u-
-16-
-19-
FRACTION INTERPRETATION:
TCLY
Total Clay, <0.002mm
MINERAL INTERPRETATION:
KK
MS
CD
ZR
TM
kaolinite
muscovite
chalcedony
zircon
tourmaline
RELATIVE PEAK SIZE:
MM
FP
PO
ZE
RU
mont-mica
plag-feldspa
plant opal
zeolite
rutile
5 Very Large
4 Large
MI
FE
PR
CL
CA
mica
Iron oxides
pyroxene
chlorite
calcite
3 Medium
INTERPRETATION (BY HORIZON):
SMEC = Smectite
PEDON MINERALOGY
BASED ON SAND/SILT: MIXED
BASED ON CLAY: SMECTITIC
FAMILY MINERALOGY:
SMECTITIC IF ARGILLIC;
COMMENTS:
MIXED
2 Small
MT
BT
GN
GS
VR
montmorillon
biotite
garnet
QZ
glass
GC
FZ
vermiculite
1 Very Small
OP
HN
quartz
opaques
hornblende
glas-coat gr
feldspathoid
6 No Peaks
FK
OW
potas feldsp
oth-weath mn
BY
TE
beryl
KH
tremolite
halloysite
-20-
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY, OREGON
S960R-003-003
SAMPLED AS
REVISED TO
PRINT DATE 07/23/97
;
;
:
FINE, SMECTICTIC, MESIC VERTIC HAPLOXERALF
VERY-FINE, SMECTICTIC, MESIC VERTIC PALEXERAlf
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
96P 349, SAMPLES 96P 2714- 2722
- PEDON
- GENERAL METHODS 181A, 2A1, 2B
-1--
DEPTH
SAMPLE
-2--
-3--
HORIZON
-4--
-5--
-6--
-7--
-.05
-2
.0002
A2
AE
E
2Bt
3Bss
3Bs
4BSS
5Cr
ORGN TOTAL
C
N
DEPTH
6Alc
PCT
(CM)
0-
7
7- 16
16- 27
27- 42
42- 91
91-120
120-135
135-153
153-175
25.0
26.6
30.5
38.2
61.5
61.5
60.7
59.3
31.7
Al
684a
<2MM
-10-
-11-
-12-
-13-
.002
-.02
53.7
53.3
49.3
45.2
28.9
28.3
29.3
30.4
61.8
21.3
20.1
20.2
16.6
9.6
10.2
10.0
10.3
6.5
38.0
36.5
35.3
33.2
23.1
21.7
21.7
23.1
48.2
10.5
11.5
13.8
18.2
42.7
42.7
33.8
28.6
10.5
-.05 -.10
(3A1)
15.7
16.8
14.0
12.0
5.8
6.6
7.6
7.3
13.7
8.8
7.1
8.3
6.9
4.3
4.5
5.0
4.4
4.3
-.25
-.50
8.8
8.9
8.2
6.7
3.8
4.1
3.8
3.6
1.4
3.4
3.4
3.2
2.6
1.3
1.3
0.9
1.4
0.5
-14-
-
C
.5
-1
0.2
0.5
0.4
0.4
0.1
0.2
0.2
0.7
0.3
-15-
-16-
-17-
-18-
-19-
-20-
- - -)(-COARSE FRACTIONS(MM)-)(>2MM)
VC
- - - - WEIGHT - - - WT
.1- PCT OF
1
2
5
20
-2
-5
-20
-75
WHOLE
75
>
<- PCT OF <75MM(3B1) ->
SOIL
0.1
0.2
0.1
TR
0.1
0.1
0.1
0.2
TR
-------2
--
--
12
--
TR
13
12
10
TR
-----
5
6
TR
5
8
--
2
-----2
--
EXTR TOTAL (- - DITH-CIT - -)(RATIO/CLAY)(ATTERBERG )(- BULK DENSITY -) COLE (- - -WATER CONTENT - -) WRD
1/3
OVEN WHOLE FIELD 1/10
15
- LIMITS FIELD
1/3
15
WHOLE
P
S
EXTRACTABLE
BAR
BAR
BAR SOIL
FE
AL
MN
CEC
BAR
LL
PI
MOIST BAR DRY
SOIL MOIST
4Ald 4Alh 401
801
801
4F1
4F
4A5
4B4
481c 481c
482a 4C1
6S3b 6R3c 6C2b 6G7a 602a
PPM <- PERCENT OF <2MM -->
PCT <0.4MM <- - G/cc - - -> CM/CM <- - -PCT OF <2MM - -> CM/CM
2.3
2.5
2.8
2.8
2.5
2.6
2.5
2.3
3.1
5.67
2.76
1.47
0.89
0.39
0.26
0.18
0.15
0.03
AVERAGES,
-9--
PCT OF <2MM
<
7
096P2714S
7- 16
96P2715S
16- 27
96P2716S
96P2717S 27- 42
96P2718S 42- 91
96P2719S 91-120
96P2720S 120-135
96P2721S 135-153
96P2722S 153-175
-8--
(- - -TOTAL - - -)(- -CLAY- -)(- -SILT- -)(- - - - - -SANDF
M
CLAY SILT SAND FINE
CO3 FINE COARSE VF
.10
.25
.05
LT
LT
.002
.02
.05
LT
.002
.002
(CM)
NO.
***
DEPTH
42- 92:
0.2
0.2
0,3
0.3
0.3
0.2
0.2
0.1
0.2
PCT CLAY
0.1
0.1
0.1
TR
--
TR
0,1
0.2
0.2
62
PCT
0.97
0.83
0.66
0.58
0.61
0.64
0.71
0.77
1.44
1.03
1.20
1.27
1.28
1.24
1.21
1.17
1.19
0.67
0.44
0.40
0.38
0.44
0.43
0.46
0.47
0.81
.1-75MM
5
1.23
1.34
1.37
1.38
2,06
2.04
1.96
1.97
0.061
0.037
0.026
0.025
0.184
0.190
0.188
0.180
39.3
30.5
28.7
27.8
40.8
42.7
44.2
44.1
16.7
11.8
12.1
14.4
26.8
26.4
27.8
28.0
25.8
0.23
0.22
0.21
0.17
0.17
8.20
0.19
0.19
***
PR IMARY CHARACTERIZATION DATA
***
PRINT DATE 07/23/97
S960R-003-003
FINE, SMECTICTIC, MESIC VERTIC HAPLOXERALF
;
SAMPLED AS
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 349, SAMPLE 96P 2714-, 2722
-
-13-
(- NH4OAC EXTRACTABLE BASES -) ACIDITY
CA
MG
NA
K
SUM
585a BASES
5B5a 5B5a
5B5a
602b
6P2b
6H5a
6N2e
602d
DEPTH
(CM)
<- -
0-
7
7- 16
16- 27
27- 42
42- 91
91-120
120-135
135-153
153-175
_ _ ----- -MEQ / 100
8.2
6.3
6.1
7.4
16.6
22.3
44.0
27.1
27.0
3.8
3.1
3.6
5.0
11.6
0.2
0.2
0.7
TR
13.1
16.3
17.2
16.6
1.0
1.3
1.3
1.3
CA
MG
NA
6N1b
601b
6P1b
--
0.5
0.3
0.3
0.3
0.5
0.4
0.4
0.4
0.4
12.5
9.7
10.2
12.9
29.4
36.8
62.0
46.0
45.3
(- -CEC- -) EXCH
SUM
NH4NA
OAC
CATS
5A8c
5D2
5A3a
>
PCT
G
18.4
17.8
15.9
14.7
13.8
10.4
5.3
5.6
4.8
30.9
27.5
26.1
27.6
43.2
47.2
67.3
51.6
50.1
24.3
22.1
20.2
22,2
37.8
39.5
43.1
45.9
45.6
TR
TR
1
1
2
2
2
2
2
K
CO3
HCO3
F
CL
SO4
NO2
6L1d
6W1b
DEPTH
6Q1b
<
0-
5E
1
1
1
2
BASE
SATURATION
SUM NH4OAC
5C3
5C1
<- -PCT- >
40
35
39
47
68
78
92
89
90
611b
6J1b 6Ulb
MEQ / LITER
6K1d
44
50
58
78
93
100
100
99
)PRED.
H2O
0.19
0.05
0.01
11.6
25.5
8.3
3,9
7.9
14.1
5.9
2.6
3.6
5.1
3.7
3.0
0.1
0.1
0.1
TR
0.2
0.3
0.4
0.5
0.3
0.6
0.2
0.1
1.2
23.9
45.4
0.6
0.5
18.3
8.8
0.8
102.4
102.6
102.6
83.3
0.1
MMHOS/CM OF 1:2 WATER EXTRACT (81) & EXCH NA AS EXTRACTABLE NA FOR LAYERS
ANALYSES:
Sw. ALL ON SIEVED <2mm BASIS
-17-
-18-
0.1
0.3
0.1
TR
1,
2,
1.90
3.63
1.54
0.96
0.17
1.23
3.08
0.92
0.46
4,
5,
-19-
CASO4 AS
(- - - -PH GYPSUM
SAT CACL2
<2MM <20MM PASTE .01M
6Fla 6F4
8C1b
8Clf
<- -PCT ->
1:2
1
TOTAL ELEC. ELEC.
SALTS COND. COND.
EST.
8A3a
81
6M1d
8A
8D5 MMHOS MMHOS
> <- -PCT- ->
/cm
/cm
NO3
-16-
51
7
7- 16
16- 27
27- 42
42- 91
91-120
120-135
135-153
153-175
715-
CARBONATE
AS CAC03
<2MM <20MM
6E1g
8E1
<- -PCT ->
WATER EXTRACTED FROM SATURATED PASTE
(
(CM)
SAR
-14-
4.8
6.4
6.8
6.8
4.8
4.5
4.4
4.3
4.4
4.8
6.6
6.8
7.0
-20- -)
H2O
8Clf
1:1
5.5
5.2
5.3
5.2
4.9
5.2
6.7
7.1
7.4
***
S960R-003-003
SAMPLED AS
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY, OREGON
;
:
PRINT DATE 07/23/97
FINE, SMECTICTIC, MESIC VERTIC HAPLOXERALF
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
- PEDON
96P 349, SAMPLES 96P 2714- 2722
- GENERAL METHODS
181A, 2A1, 28
-4--
ACID OXALATE EXTRACTION
SAMPLE
NO.
96P2714
96P2715
96P2716
96P2717
96P2718
96P2719
96P2720
96P2721
96P2722
HZ
NO
1
2
3
4
5
6
7
8
9
OPT
DEN
8J
0.10
0.09
0.08
0.06
0.02
0.03
0.02
0.02
0.01
AL
FE
SI
6C9b
6V2b 6G12b
0.74
0.82
0.65
0.48
0.22
0.24
0.17
0.17
0.11
0.12
0.11
0.11
0.10
0.13
0.16
0.15
0.16
0.14
-10-
PHOSPHOUS
CITRET
ACID
6S4b 6S5
KCL
MN
6D3b
TOTAL
<-PCT of< 2mm-><-Ppm -><
0.19
0.20
0.24
0.23
0.23
0.16
0.14
0.14
0.13
C
6A2e
-11-
-12-
-13-
-14-
-15-
-16-
-17-
-18-
-19-
-20-
(- -WATER CONTENT- - )(- - - - WATER DISPERSIBLE - - - - ) MIN
AGGRT
0.06
15
12<- - PIPETTE - - >< - HYDROMETER - > SOIL STABL
BAR
BAR
BAR
BAR CLAY SILT SAND CLAY SILT SAND
CONT <5mm
4B1c
4Bla
481a 4B2b <- - - 3A1c - - -><- - - SML - - -> 8F1
4G1
< 2mm
>< PCT>
PERCENT of
25.1
22.3
21.5
22.3
38.6
36.4
39.5
39.1
37.7
***
PRIMARY CHARACTERIZATION DATA
***
S960R-003-003
SAMPLED AS
;
FINE, SMECTICTIC, MESIC VERTIC HAPLOXERALF
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 349, SAMPLE 96P 2714- 2722
PRINT DATE 07/25/97
-13<
SAMPLE
FRACT <
ION <
NUMBER
<- - >< -
<
96P2716
96P2718
96P2719
96P2721
96P2722
TCLY
TCLY
TCLY
TCLY
TCLY
KK
MT
MT
MT
MT
<
FRACT <
SAMPLE
ION <
<
NUMBER
96P2716
96P2716
96P2716
96P2716
96P2718
96P2718
96P2718
96P2718
96P2719
96P2719
)6P2719
)6P2719
)6P2721
96P2721
)6P2721
)6P2721
)6P2722
)6P2722
96P2722
< - -><
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
CS
><
><
><
><
X-RAY
7A21
-
3
4
4
4
4
- - peak size
MM
KK
KK
KK
FO
2
3
2
2
2
MI
VR
MI
QZ
KK
2
2
2
1
2
MT 2
MI 2
QZ 1
QZ 2
QZ 1
MI
QZ 1
1
-15-
-16-
CLAY MINERALOGY (<.002mm)
-><
THERMAL
ELEMENTAL
DTA - ->< - TGA - -> S102 AL203 Fe203 MgO
Ca0
K20
7A6b
><
7A4c
><
7C4a- - -- - -><
Percent
Percent
SAND
SILT MINERALOGY (2.0-0.002mm)
THERMAL
-><
OPTICAL
>< - DTA - ->< - TGA - ->TOT RE<
GRAIN COUNT
- 7A2i - - - - >< - 7A3c - >< - 7A4c
><
781a
Peak Size - - ->< - - - Percent - - - -><
percent
X-RAY
-17-
><
Na20 <
-><
><
-18-
-19-
-20>
-> EGME
> REIN
INTER
PRETA
>
702
TION
-><mg/g>< - ->
CMIX
SMEC
SMEC
SMEC
SMEC
- ><
55
48
45
CS
CS
CS
CS
CS
CS
CS
CS
-14-
53
53
QZ44
PO 3
ZEtr
RUtr
QZ40
MS 3
POtr
GOtr
FK35
OW 2
BYtr
GNtr
QZ4O
CD 2
FZ 1
RUtr
QZ39
BT 4
HNtr
FK28
BT 3
CLtr
GAtr
FK34
PR 2
CDtr
SStr
QZ33
CD 2
FZtr
CTtr
FK32
BT 1
ZRtr
TMtr
FK23
CD 3
GNtr
FP 5
OW 2
ZRtr
ZOtr
FP 7
BT 2
CLtr
RUtr
FP 9
MS 1
POtr
FP 7
HN 1
GNtr
MZtr
FE 9
OP 2
POtr
MS 5
PR 1
BYtr
FE 4
GS 1
BYtr
TEtr
FE 6
PR
1
ZRtr
FE 6
PR 1
ZEtr
GOtr
FP 8
PR
1
RUtr
><
><
><
><
FE 4
HN 1
GNtr
OP 3
CD 1
TMtr
OP 4
OWtr
FZtr
TMtr
OP 4
HN 1
RUtr
HN 3
ZRtr
GNtr
OP 4
OW 1
CTtr
MS 3
BY 1
POtr
MS 6
OW 4
ZRtr
CTtr
FZ 1
BYtr
BT 3
ZE 1
CLtr
>
> INTER
> PRETA
>
TION
><
->
PRIMARY CHARACTERIZATION DATA
***
***
S960R-003-003
SAMPLED AS
; FINE, SMECTICTIC, MESIC VERTIC HAPLOXERALF
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 349, SAMPLE 96P 2714- 2722
PRINT DATE 07/25/97
.
-2--
-3--
-4--
-5--
-6--
-7--
-8--
-9--
-10-
-11-
-12-
-13-
-14-
-15-
-16-
-17-
-18-
-19-
FRACTION INTERPRETATION:
TCLY. Total Clay, <0.002mm
Coarse Silt, 0.02-0.05mm
CSI
MINERAL INTERPRETATION:
KK
FP
OW
ZR
ZO
kaolinite
plag-feldspa
oth-weath mn
zircon
zoisfte
RELATIVE PEAK SIZE:
MM
MS
PR
mont-mica
muscovite
pyroxene
BY
VR
beryl
vermiculite
5 Very Large
4 Large
MI
FE
HN
GN
GS
3 Medium
INTERPRETATION (BY HORIZON):
CMIX . Mixed - Clay
PEDON MINERALOGY
BASED ON SAND/SILT:
Mixed
BASED ON CLAY:
SmectitIc
FAMILY MINERALOGY:
Smectitic
COMMENTS:
mica
Iron oxides
hornblende
garnet
glass
SMEC = Smectlte
2 Small
MT
OP
CD
TM
FZ
montmorlllon
opaques
chalcedony
tourmaline
feldspathoid
1 Very Small
QZ
PO
ZE
RU
GO
quartz
plant opal
zeolite
rutile
glaucophane
6 No Peaks
FK
BT
CL
GA
SS
potas feldsp
blotlte
chlorite
glass aggreg
spon splcule
-20-
***
5960R-003-004
SAMPLED AS
REVISED TO
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY, OREGON
:
SND
PRINT DATE 07/23/97
; FINE SMECTITIC, MESIC VERTIC NAPLOXERALF
FINE, SMECTICTIC, MESIC TYPIC HAPLOXERERT
:
;
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
- PEDON
96P 350, SAMPLES 96P 2723- 2729
- GENERAL METHODS
1B1A, 2A1, 2B
-1--
SAMPLE
NO.
DEPTH
-2--
096P2723S
6
6- 18
96P2724S
96P2725S
18- 35
96P2726S 35- 51
96P27275 51- 90
96P2728S 90-133
96P2729S 133-163
HORIZON
Al
A2
BA
Btl
Bt2
Bssl
Bss2
ORGN TOTAL
C
N
DEPTH
0-
-3--
(CM)
(CM)
6Alc
PCT
6
6- 18
18- 35
35- 51
51- 90
90-133
133-163
raw
)
9.16
3.99
2.43
1.57
1.03
0.95
0.79
AVERAGES,
6B4a
<2MM
-4--
-5--
-6--
-7--
-8--
-9--
-10-
-11-
-12-
-13-
(- - -TOTAL - - -)(- -CLAY- -)(- -SILT- -)(- - - - - -SANDCLAY SILT SAND FINE
CO3 FINE COARSE
VF
F
14
LT
.002
.05
LT
LT
.002
.02
.05
.10
.25
-2
.002 -.05
.0002
.002
-.02 -.05 -.10
-.25 -.50
<
PCT OF <2MM (3A1)
43.8
47.4
52.4
54.5
56.1
58.8
62.0
46.4
44.8
37.2
33.7
36.9
33.9
32.2
9.8
7.8
10.4
11.8
7.0
7.3
5.8
23.5
26.4
29.9
30.7
29.1
24.9
23.2
36.6
37.2
31.7
28.3
29.2
27.6
27.2
9.8
7.6
5.5
5.4
7.7
6.3
5.0
3.9
9.7
3.5
3.0
2.0
4.3
3.2
3.4
2.5
3.1
3.2
2.8
2.2
2.0
1.6
1.1
1.9
-14-
-
C
.5
-1
0.8
0.4
2.7
1.5
1.8
1.5
0.6
0.5
0.5
0.2
0.1
-15-
-16-
-17-
-18-
-19-
-20-
- - -)(-COARSE FRACTIONS(MM)-)(>2MM)
VC
- - - - WEIGHT - - - WT
1
2
5
20
.1- PCT OF
-2
-5
-20
-75
75
WHOLE
>
<- PCT OF <75MM(3B1)-> SOIL
0.1
0.1
0.4
1.1
0.2
--
TR
--------
--
--6
4
7
9
5
3
3
--------
EXTR TOTAL (- - DITH-CIT - -)(RATIO/CLAY)(ATTERBERG )(- BULK DENSITY -) COLE (- - -WATER CONTENT
- -)
WRD
P
S
EXTRACTABLE
15
- LIMITS - FIELD
1/3
OVEN WHOLE FIELD 1/10
1/3
15
WHOLE
FE
AL
MN
CEC
BAR
LL
PI
MOIST BAR DRY
SOIL MOIST
BAR
BAR
BAR
SOIL
6S3b 6R3c 6C2b
6G7a 6D2a
801
801
4F1
4F
4A5
4Ald 4Alh 401
484
481c
481c 4B2a 4C1
PPM <- PERCENT OF <2MM -->
PCT <0.4MM <- - G/cc - - -> CM/CM <- =:-PCT OF <2MM - -> CM/CM
3.6
0.3
0.3
1.20 0.79
0.23 0.32 0.116
203.4 34.5 0.39
4.5
0.4
0.3
1.03 0.51
1.01
1.29 0.085
32.9 24.0 0.09
4.8
0.4
0.4 0.87 0.45
1.19
1.75 0.137
42,1 23.4 0.22
4.7
0.4
0.5
0.89 0.45
1.12
1.51 0.105
38.0 24.4 0.15
3.8
0.2
0.4
0.49
1.19
1.48 0.075
38.8
27.6 0.13
2.6
0.2
0.2 0.96 0.48
1.23
1.88 0.152
40.6
28.3 0.15
3.1
0.2
0.2 0.95 0.48
1.15
1.87 0.176
45.5
29.8 0.18
DEPTH
25-100:
PCT CLAY
56
PCT
.1-75MM
6
PRIMARY CHARACTERIZATION DATA
***
***
PRINT DATE 07/23/97
S960R-003-004
FINE SMECTITIC, MESIC VERTIC HAPLOXERALF
;
SND
SAMPLED AS
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 350, SAMPLE 96P 2723- 2729
:
-13-
(- -CEC- -) EXCH
NA
NH4SUM
OAC
CATS
502
5A3a 5A8c
>
PCT
(- NH4OAC EXTRACTABLE BASES -) ACIDCA
5B5a
6N2e
DEPTH
(CM)
MG
5B5a
602d
NA
5B5a
6P2b
<
0-
6
6- 18
18- 35
35- 51
51- 90
90-133
133-163
SUM
5B5a BASES
602b
K
ITY
6H5a
MEQ / 100 G
18.7
16.6
18.5
19.9
7.3
7.7
9.4
11.0
0.6
0.2
0.3
0.4
0.4
0.4
0.4
27.6
24.9
28.6
31.7
33.6
33.7
18.8
19.2
1.1
1.0
0.4
0.4
53.9
54.3
1.0
62.1
54.9
54.6
55.1
34.5
30.0
26.0
23.4
13.2
7.4
8.1
52.5
48.6
45.8
48.6
1
2
2
88
87
96
92
WATER EXTRACTED FROM SATURATED PASTE
(
CA
MG
DEPTH
6N1b
< - -
(CM)
0-
6
2.0
NA
601b
6Plb
1.1
1.1
.. ------
SO4
NO2
6J1b 6U16
601b 611b
- _ - - -MEQ / LITER
6Kld
6L1d
6W1b
0.7
0.9
1.1
0.2
K
0.3
CO3
HCO3
1.7
F
CL.
44
53
51
62
65
1
56.4
58.9
5E
BASE
SATURATION
SUM NH4OAC
5C1
5C3
<- -PCT- >
45
52
58
1
TR
13.2
61.3
62.4
SAR
1
-14-
CARBONATE
AS CAC03
<2MM <20MM
8E1
6Elg
<- -PCT ->
)PRED.
TOTAL ELEC. ELEC.
SALTS COND. COND.
NO3
81
8A3a
EST.
805 MMHOS MMHOS
8A
6M1d
/cm
/cm
> <- -PCT- ->
TR
MMHOS/CM OF 1:2 WATER EXTRACT (81) & EXCH NA AS EXTRACTABLE NA FOR LAYERS
S. ALL ON SIEVED <2mm BASIS
2,
3,
-18-
0.55
4,
3.21
0.16
0.05
0.04
0.05
0.13
0.07
5,
6,
-19-
CASO4 AS (- - - -PH SAT CACL2
GYPSUM
<2MM <20MM PASTE .01M
8C1b 8C1f
6F4
6F1a
1:2
<- -PCT ->
H2O
167.9
-17-
5.0
6- 18
18- 35
35- 51
51- 90
90-133
133-163
ANALYSES:
-16-
-15-
7,
4.6
4.4
4.8
5.0
5.9
7.0
6.9
-20- -)
H2O
8C1f
1:1
5.3
4.9
5.4
5.8
6.5
7.1
7.5
***
5960H-003 -004
PRIMARY
CHARACTERIZATION DATA
(BENTON COUNTY; OREGON
**
PRINT DATE 07/23/97
SAMPLED AS
:
SW)
;
FINE SMECTITIC, MESIC VERTIC HAPLOXERALF
UNITED STATES DEPARTMENT OF AGRICULTURE
NATURAL RESOURCES CONSERVATION SERVICE
NATIONAL SOIL SURVEY CENTER
SOIL SURVEY LABORATORY
LINCOLN, NEBRASKA 68508-3866
SSL - PROJECT 96P 69, (CP960R145) OR-WET-BENTON CO.-96
- PEDON
96P 350, SAMPLES 96P 2723- 2729
- GENERAL METHODS 181A, 2A1, 2B
-WACID OXALATE EXTRACTION
SAMPLE
NO.
96P2723
96P2724
96P2725
96P2726
96P2727
96P2728
96P2729
HZ
NO
OPT
DEN
8J
FE
SI
AL
6C9b 6V2b 6G12b
<- P C T o f < 2 m m - > < -
1
2
3
4
5
6
7
0.25
0.20
0.23
0.12
0.09
0.11
PHOSPHOUS
CITACID
6S5
RET
6S4b
1.66
2.14
1.83
1.12
0.62
0.82
0.15
0.16
0.19
0.25
0.27
0.28
0.36
0.42
0.45
0.35
0.34
0.33
P
KCL
MN
TOTAL
C
6D3b 6A2e
P M ->< -
-11-
-12-
-13-
-14-
-15-
-16-
-W-
-18-
-19-
-20-
(- -WATER CONTENT- - )(- - - - WATER DISPERSIBLE - - - - ) MIN
AGGRT
0.06
1215
<- - PIPETTE - - >< - HYDROMETER - > SOIL STABL
BAR
BAR
BAR
BAR CLAY SILT
SAND CLAY SILT SAND
CONT <5mm
481c 4B1a 4Bla 4B2b <- - - 3A1c - - -><- - - SML
- - -> 8F1
4G1
- - - ----- -PERCENT of < 2 m m
>< PCT>
30.0
31.7
31.0
31.9
38.2
39.8
41.7
PRIMARY CHARACTERIZATION DATA
***
S960R-003-004
SAMPLED AS
SND
; FINE SMECTITIC, MESIC VERTIC HAPLOXERALF
USDA-NRCS-NSSC-SOIL SURVEY LABORATORY ; PEDON 96P 350, SAMPLE 96P 2723- 2729
PRINT DATE 07/25/97
:
-1--
-2--
-3--
-4--
-5--
-6--
-7--
-8--
<
FRACT <
SAMPLE
<
NUMBER
Tab---:
7A2I
<- - >< - - - - peak size
TCLY
TCLY
TCLY
TCLY
96P2725
96P2727
96P2728
96P2729
MT
MT
MT
MT
3
3
9
3
KK
KM
VR
VR
2
2
2
2
VR
KH
KK
KK
2
2
2
2
><
LE
QZ
KH
KH
1
1
2
2
-10-
-11-
-12-
-13-
CLAY MINERALOGY (<,0e2mm)
-><
THERMAL
><
><
X-RAY
ION <
-9--
- ILIc---:<5.!0! 1.1.L.!°.!
-15-
-16-
-17-
-18-
><
ELEMENTAL
F...!0! -1g4a -Cr. ...T. .N.!224
Percent
><
-><
Percent
-14-
-19-
-20>
-> EGME
INTER
REIN
PRETA
:
-><mg/g>4 - ->
QZ 1
SMEC
SMEC
SMEC
SMEC
<
SAND
SILT MINERALOGY (2.0-0.002mm)
- -><
THERMAL
-><
OPTICAL
>< - DTA - ->< - TGA - ->TOT RE<
GRAIN COUNT
- - 7A21 - - - - >< - 7A3c - >< - yAlm - ><
781a
< - ->< - - - Peak Size - - ->< - - - Percent - - - -><
Percent
FRACT <
SAMPLE
NUMBER
96P2725
96P2725
96P2725
X-RAY
CSI
CSI
CSI
QZ26
BT 4
60
GS
1
FK17
PO 4
OWtr
OP16
CD 3
ZRtr
FE11
MS 2
ZEtr
>
><
><
><
><
ION <
< -
FP 9
HN 2
GNtr
> INTER
> PRETA
> TION
->< - ->
AM 4
PR
1
CRtr
FRACTION INTERPRETATION:
TCLY
Total Clay, <0.002mm
Coarse Silt, 0.02-0.05mm
CSI
MINERAL INTERPRETATION:
MT
OP
CD
ZR
montmorilion
opaques
chalcedony
zircon
RELATIVE PEAK SIZE:
KK
FE
MS
ZE
kaolinite
iron oxides
muscovite
zeolite
5 Very Large
INTERPRETATION (BY HORIZON):
SMEC = Smectite
PEDON MINERALOGY
BASED ON SAND/SILT:
BASED ON CLAY:
FAMILY MINERALOGY:
COMMENTS:
4 Large
VR
FP
HN
GN
vermiculite
plag-feldspa
hornblende
garnet
3 Medium
2 Small
LE
AM
PR
CR
lepldocroclt
amphibole
pyroxene
cristobalite
1 Very Small
QZ
BT
GS
KH
quartz
biotite
glass
halloysite
6 No Peaks
FK
PO
OW
potas feldsp
plant opal
oth-weath mn
212
Appendix B
Soil Profile Descriptions
213
PIT 1
Pedon classification: Ultic Haploxeroll
Pedon description
Al
0 to 7 cm; dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; moderate
fine subangular blocky structure; slightly hard, friable; sticky and
slightly plastic; many very fine roots; many very fine tubular pores; clear
smooth boundary.
A2
7 to 19 cm; dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; few fine
iron concretions less than 0.5 millimeters in diameter that streak when
ped is scraped; moderate fine subangular blocky structure; hard, friable;
sticky and slightly plastic; common very fine roots; many very fine
tubular pores; gradual smooth boundary.
A3
19 to 46 cm; dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; few
fine iron concretions less than 0.5 millimeters in diameter; moderate
medium subangular blocky structure; hard, friable; sticky and slightly
plastic; few very fine roots; many very fine and common fine tubular
pores; less than 1 percent sandstone fragments; gradual smooth
boundary.
BA
46 to 65 cm; brown (10YR 4/3) clay loam, pale brown (10 YR 6/3) dry;
few fine faint dark grayish brown (10YR 4/2) depletions along pores; few
fine iron concretions less than 0.5 millimeters in diameter; weak medium
prismatic structure parting to moderate medium subangular blocky;
hard, friable; sticky and slightly plastic; few very fine, few medium, and
few coarse roots; many very fine and few fine tubular pores; 1 percent
sandstone fragments; gradual smooth boundary.
Bwl
65 to 95 cm; yellowish brown (10YR 5/4) clay loam, light yellowish brown
(10YR 6/4) dry; few fine faint yellowish brownish (10YR 5/6) masses of
iron, faint brownish yellow (10YR 6/6) dry; moderate medium prismatic
structure; hard, friable; slightly sticky and slightly plastic; few very fine,
few fine, and few medium roots; many very fine and few fine tubular
pores; 2 percent sandstone fragments; gradual irregular boundary.
Bw2/Crt
95 to 130 cm; The Bw2 part is dark yellowish brown (10YR 4/4) clay
loam, light yellowish brown (10YR 6/4) dry. It has weak coarse
subangular blocky structure; slightly hard, friable; slightly sticky and
slightly plastic; few very fine roots. It contains 50 percent sandstone
fragments. The Crt part is light yellowish brown (2.5Y 6/3) and dark
yellowish brown (10YR 4/6) weathered sandstone, pale yellow (2.5Y 7/3)
and dark yellowish brown (10YR 4/6) dry that has common prominent
strong brown (7.5YR 5/8) and dark brown (7.5YR 3/4) iron and clay
coatings on fracture planes. Some fracture planes have clay loam
accumulations that are 1 to 5 millimeters thick. The horizon has a
gradual wavy boundary.
2Crt
130 to 155 cm; weathered and interbedded sandstone and siltstone; few
very fine roots along fractures; common distinct clay films on fracture
planes.
214
PIT 2
Pedon classification: Aeric Humaquept
Pedon description
Al
0 to 7 cm; very dark grayish brown (10YR 3/2+) silt loam, brown (10YR
5/3) dry; moderate very fine subangular blocky structure; hard, friable;
slightly sticky and slightly plastic; many very fine and common fine
roots; clear smooth boundary.
A2
7 to 14 cm; very dark grayish brown (10YR 3/2+) silt loam, brown (10YR
5/3) dry; many fine faint yellowish red (5YR 4/6) and strong brown
(7.5YR 4/6) masses of iron, distinct yellowish red (5YR 5/6) and strong
brown (7.5YR 5/6) dry; moderate very fine subangular blocky structure;
hard, friable; slightly sticky and slightly plastic; many very fine and
common fine roots; abrupt smooth boundary.
A3
14 to 27 cm; very dark grayish brown (10YR 3+/2) silt loam, grayish
brown (10YR 5+/2) dry; many fine distinct and common medium distinct
dark yellowish brown (10YR 4/6) and dark brown (7.5YR 3/4) masses of
iron, prominent yellowish brown (10YR 5/6) and brown (7.5YR 4/4) dry;
few fine manganese nodules; moderate medium subangular blocky
structure; hard, friable; slightly sticky and slightly plastic; many very fine
and common fine roots; common very fine irregular pores; gradual
smooth boundary.
AB
27 to 36 cm; dark grayish brown (10YR 4/2) silt loam, grayish brown
(10YR 5+/2) dry; common fine prominent and few medium prominent
dark yellowish brown (10YR 4/6) and strong brown (7.5YR 4/6) masses
of iron, yellowish brown (10YR 5/6) and strong brown (7.5YR 5/6) dry;
few fine manganese nodules less than 1.0 mm in diameter; weak coarse
subangular blocky structure; hard, friable; sticky and slightly plastic;
many very fine and common fine roots; common very fine tubular pores;
gradual smooth boundary.
B/E
36 to 50 cm; 35 percent dark grayish brown (10YR 5/2), grayish brown
(10YR 6/2) dry and 65 percent dark yellowish brown (10YR 4/4) and
strong brown (7.5YR 4/6) silt loam, light yellowish brown (10YR 6/4) and
strong brown (7.5YR 5/6) dry; planar faces of peds have low chroma
depletion about 1.0 mm thick; few fine manganese nodules less than 2
millimeters in diameter; weak medium prismatic structure parting to
moderate medium subangular blocky; hard, friable; sticky and slightly
plastic; common very fine roots; common very fine vesicular pores; clear
smooth boundary.
E/ B
50 to 70 cm; 60 percent grayish brown (10YR 5/2), light gray (10YR 7/2)
dry and 40 percent yellowish brown (10YR 5/6) and strong brown (7.5YR
4/6) silty clay loam, brownish yellow (10YR 6/6) and strong brown
(7.5YR 5/6) dry; planar faces of peds are more strongly depleted and
have thicker layer of depletion than horizon above; few fine manganese
nodules less than 2 millimeters in diameter; moderate medium prismatic
structure parting to moderate coarse subangular blocky; hard, friable;
215
sticky and slightly plastic; few very fine roots; common very fine vesicular
pores; abrupt wavy boundary.
2Bt1
70 to 92 cm; grayish brown (2.5Y 5/2) silty clay, light brownish gray
(2.5Y 6/2) dry; many fine distinct strong brown (7.5YR 5/6) and strong
brown (7.5YR 5 / 8) masses of iron, distinct reddish yellow (7.5YR 6 / 6)
and reddish yellow (7.5YR 6/8) dry; massive structure; very hard, very
firm; sticky and plastic; few very fine roots; few very fine tubular pores;
few distinct clay films in pores; very few distinct slickensides; gradual
wavy boundary.
3Bt2
92 to 109 cm; light olive brown (2.5Y 5/3+) silty clay, light olive brown
(2.5Y 6/3+) dry; common fine faint yellowish brown (10YR 5/8) masses of
iron, faint brownish yellow (10YR 6/8) dry; few fine iron nodules and few
fine manganese concretions; massive structure; very hard, very firm;
sticky and plastic; few very fine roots; few very fine tubular pores; few
distinct clay films in pores; few distinct slickensides; 2 percent sandstone
fragments; gradual smooth boundary.
3Bss
109 to 142 cm; olive brown (2.5Y 4/4) silty clay, light yellowish brown
(2.5Y 6/4) dry; common medium distinct olive gray (5Y 5/2) depletions
along pores; common fine faint brownish yellow (10YR 5/8) masses of
iron, faint yellowish brown (10YR 6/8) dry; few fine iron nodules and few
fine manganese concretions; massive structure; very hard, very firm;
sticky and plastic; few very fine roots; few very fine tubular pores; few
distinct clay films in pores; common prominent slickensides; 2 percent
sandstone fragments; gradual smooth boundary.
4BCt1
142 to 155 cm; light yellowish brown (2.5Y 6/3), strong brown (7.5YR
5/6), and strong brown (7.5YR 4/6) silty clay loam, pale yellow (2.5Y
7/3), reddish yellow (7.5YR 6/6), and strong brown (7.5YR 5/6) dry with
yellowish brown (10YR 5/8) areas of less weathered sandstone, brownish
yellow (10YR 6/8) dry; very few prominent black (N 2.5/) manganese
stains on fracture planes; few very fine roots; few very fine tubular pores;
very few prominent clay films along root channels; few fine prominent
white gypsum crystal clusters; abrupt broken boundary.
4BCt2
155 to 170 cm; light yellowish brown (2.5Y 6/3) silty clay loam, pale
yellow (2.5Y 7/3) dry with light yellowish brown (2.5Y 6/4) and brownish
yellow (10YR 6/8) areas of less weathered sandstone, pale yellow (2.5Y
7/4) and yellow (10YR 7/8) dry; very few prominent black (N 2.5/)
manganese stains on fracture planes; few very fine roots; very few
prominent clay films along root channels.
216
PIT 3
Pedon classification: Vertic Epiaquept
Pedon description
Al
0 to 7 cm; very dark grayish brown (10YR 3/2+) silt loam, grayish brown
(10YR 5/2+) dry; moderate medium granular structure; slightly hard,
friable; slightly sticky and slightly plastic; many very fine roots; clear
smooth boundary.
A2
7 to 16 cm; dark grayish brown (10YR 4/2) silt loam, grayish brown
(10YR 5+/2) dry; common distinct strong brown (7.5YR 4/6) oxidized
rhizospheres; many fine distinct yellowish red (5YR 4/6) and strong
brown (7.5YR 4/6) masses of iron, prominent yellowish red (5YR 5/6)
and strong brown (7.5YR 5/6) dry; few fine manganese-iron concretions;
weak coarse subangular blocky structure parting to moderate fine
subangular blocky; hard, friable; slightly sticky and slightly plastic;
many very fine roots; clear smooth boundary.
B/E
16 to 27 cm; 30 percent dark grayish brown (10YR 4/2+), light brownish
gray (10YR 6/2+) dry and 50 percent dark yellowish brown (10YR 4/6)
and strong brown (7.5YR 4/6), yellowish brown (10YR 5/6) and strong
brown (7.5YR 5/6) dry and 20 percent dark yellowish brown (10YR 4/4)
silt loam, yellowish brown (10YR 5/4) dry; few distinct strong brown
(7.5YR 5/8) oxidized rhizospheres; few fine manganese-iron concretions
less than 1.0 mm in diameter; common prominent black (N 2.5/)
manganese stains on ped faces; moderate medium subangular blocky
structure; very hard, firm; slight sticky and slightly plastic; common very
fine and few fine roots; few fine tubular pores; clear smooth boundary.
E/B
27 to 42 cm; 50 percent grayish brown (10YR 5/2), light gray (10YR 7/2)
dry and 35 percent yellowish brown (10YR 5/6) and strong brown (7.5YR
5/6) silty clay loam, brownish yellow (10YR 6/6) and reddish yellow
(7.5YR 6/6) dry; 15 percent common fine distinct strong brown (7.5YR
4/6) masses of iron, distinct strong brown (7.5YR 5/6) dry; few fine
manganese-iron concretions less than 1.0 mm in diameter; moderate
coarse subangular blocky structure; very hard, firm; sticky and plastic;
common very fine roots; few fine tubular pores; abrupt wavy boundary.
2Bt
42 to 91 cm; dark grayish brown (2.5Y 4/2) silty clay, light brownish
gray (2.5Y 6/2) dry; many fine prominent yellowish brown (10YR 5/8)
masses of iron, prominent brownish yellow (10YR 6/8) dry; few fine iron
concretions; massive structure; very hard, firm; sticky and plastic;
common very fine roots; few distinct clay films along root channels; few
distinct slickensides starting at 65 cm; gradual smooth boundary.
3Bss
91 to 120 cm; dark grayish brown (2.5Y 4/2) and light olive brown (2.5Y
5/3) silty clay, light brownish gray (2.5Y 6/2) and light yellowish brown
(2.5Y 6/3) dry; common fine faint yellowish brown (10YR 5/6) masses of
iron, faint yellowish brown (10YR 5/6) dry; few fine iron concretions; few
fine distinct black (N 2.51) masses of manganese; massive structure; very
hard, firm; sticky and plastic; few very fine roots; few faint clay films
217
along root channels; many distinct slickensides; gradual smooth
boundary.
3Bsstyl
120 to 135 cm; light olive brown (2.5Y 5/4) and light olive brown (2.5Y
5/3) clay, light yellowish brown (2.5Y 6/4) and light yellowish brown
(2.5Y 6/3) dry; common fine faint yellowish brown (10YR 5/6) masses of
iron, faint yellowish brown (10YR 5/6) dry; common fine black
manganese nodules; few fine prominent black (N 2.5/) masses of
manganese; massive structure; very hard, firm; sticky and plastic; few
very fine roots; few very fine tubular pores; very few faint clay films along
root channels and few distinct clay films on ped faces; many distinct
slickensides; 1 percent sandstone fragments; few medium distinct and
few fine distinct clear gypsum crystals and few fine and few medium
prominent white gypsum crystal clusters; gradual smooth boundary.
3Bssty2
135 to 153 cm; light olive brown (2.5Y 5/4) silty clay, light yellowish
brown (2.5Y6/4) dry; few fine manganese nodules; few prominent black
(N 2.5/) manganese stains on ped faces; few distinct black (N 2.5/)
manganese coatings on sandstone fragments; weak coarse subangular
blocky structure; very hard, firm; sticky and plastic; few very fine roots;
few prominent clay films along root channels and few distinct clay films
on ped faces; many distinct slickensides; 5 percent sandstone fragments;
few fine prominent white gypsum crystal clusters; gradual smooth
boundary.
4BCt
153 to 175 cm; light yellowish brown (2.5Y6/3) and yellowish brown
(10YR 5/8) silty clay loam, pale yellow (2.5Y 7/3) and brownish yellow
(10 YR 6/8) dry; common prominent black (N2.5/) manganese stains on
fracture planes; few very fine roots; few distinct clay films along root
channels and few distinct clay films on fracture planes.
218
PIT 4
Pedon classification: Typic Endoaquert
Pedon description
Al
0 to 6 cm; very dark gray (10YR 3/1) silt loam, dark gray (10YR 4/1) dry;
many distinct strong brown (7.5YR 4/6) oxidized rhizospheres; moderate
medium granular structure; slightly hard, friable; slightly sticky and
slightly plastic; many very fine roots; clear smooth boundary.
A2
6 to 18 cm; very dark gray (10YR 3/1) silt loam, dark gray (10YR 4/1)
dry; many distinct strong brown (7.5YR 5/8) oxidized rhizospheres; many
fine distinct strong brown (7.5YR 4/6), many fine faint dark brown
(7.5YR 3/4), and common fine distinct yellowish red (5YR 4/6) masses of
iron, faint strong brown (7.5YR 5/8) and strong brown (7.5YR 4/6) and
faint yellowish red (5YR 5/8) dry; very few faint black (N 2.5/)
manganese stains on ped faces; moderate fine subangular blocky
structure; hard, friable; sticky and slightly plastic; many very fine roots,
common very fine pores; clear smooth boundary.
AB
18 to 35 cm; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR
4/1) dry; few distinct strong brown (7.5YR 5/8) oxidized rhizospheres;
many fine distinct strong brown (7.5YR 4/6) and common fine faint dark
reddish brown (5YR 3/4) masses of iron, prominent strong brown (7.5YR
5/6) and distinct reddish brown (5YR 4/4) dry; isolated areas of many
medium distinct yellowish red (5YR 4/6) masses of iron, yellowish brown
(5YR 5/6) dry; few fine faint iron concentrations; common medium
distinct manganese-iron cemented granular peds; common fine
manganese nodules; few distinct black (N 2.5/) manganese stains on ped
faces; moderate fine subang-ular blocky structure; hard, friable; sticky
and plastic; many very fine roots, common very fine pores; clear smooth
boundary.
BA
35 to 51 cm; black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1)
dry; many fine distinct strong brown (7.5YR 4/6) and common fine faint
dark brown (7.5YR 3/4) masses of iron, prominent strong brown (7.5YR
5/6) and (7.5YR 4/6) dry; common medium distinct manganese-iron
cemented granular peds; moderate fine subangular blocky structure;
hard, friable; sticky and plastic; common very fine roots; common very
fine pores; 1 percent basalt fragments; clear wavy boundary.
Bt
51 to 90 cm; black (10YR 2/1) silty clay, very dark gray (10YR 3/1) dry;
few fine and medium manganese nodules; moderate coarse prismatic
structure when dry; extremely hard, firm; sticky and plastic; few very
fine roots; few very fine pores; few faint clay films; very few distinct
slickensides; clear smooth boundary.
Bssl
90 to 133 cm; black (10YR 2/1) silty clay, very dark gray (10YR 3/1) dry;
few fine faint dark yellowish brown (10YR 3/4) masses of iron, dark
yellowish brown (10YR 4/4) dry; moderate medium prismatic structure
when dry; extremely hard, firm; sticky and plastic; few very fine roots;
few very fine pores; common distinct slickensides; clear wavy boundary.
219
Bss2
133 to 163 cm; black (10YR 2/1) silty clay, very dark gray (10YR 3/1)
dry; few fine faint dark yellowish brown (10YR 3/4) masses of iron, dark
yellowish brown (10YR 4/4) dry; massive structure; extremely hard, firm;
sticky and plastic; few very fine roots; many distinct slickensides.
220
Appendix C
Field Measurement Data
221
KEY FOR FIELD MEASUREMENT DATA
Instrument* identification:
W = well
P
E
= piezometer
= platinum electrode
TC = thermocouple
DO = dissolved oxygen
*instrument depths in centimeters
*instrument replication given as 1,2, or 3 (if applicable)
Example: P-75-2
Data record is for a piezometer at the 75 cm and is the
second replicate instrument at this depth for this soil plot.
Data identification:
Field data
piezometer measurements adjusted to subtract the length of
piezometric pipe that extended above the soil surface.
all other measurements unadjusted.
Corrected (Average)
average values of replicated field data.
electrode data corrected to a standard hydrogen electrode value (Eh)
by adding +244mV.
electrode data adjusted by factor of -59mV for each soil pH unit
change from pH 7.
Raw PZ data
readings taken in the field without any adjustments.
Miscellaneous:
Highlighted data
- extrapolated data that was filled in to facilitate graphing.
222
WITHAM HILL DATA
Field Data
W-100
Site 1
Benton County
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
-27.8
-14.9
-7.3
-6.9
P-75-1
P-75-2
P-75-3
P-35-1
-17.8
-6.7
0.3
P-35-2
P-35-3
P-20-1
-5.8
-4.7
-4.5
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
377
333
390
109
64
74
80
163
149
322
341
301
325
295
338
282
382
102
167
156
368
80
165
149
230
227
240
213
332
288
308
274
344
250
336
282
337
340
347
11.9
11.3
11.3
14.4
11.3
10.2
8.8
1.4
10.5
10.4
10.6
13.3
10.7
10.0
9.6
351
E-10-1
E-10-2
E-10-3
375
372
387
TC-50
TC-30
TC-10
AMBIENT
11.8
10.4
7.5
377
351
DO-W100
11.8
D075-1
D075-2
D075-3
10.6
10.4
D035-1
D035-2
D035-3
9.3
9.7
11.2
D020-1
D020-2
D020-3
8.7
9.2
9.4
Corrected
Average
-98.1
9.1
9.4
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
W-100
P-75
P-35
P-20
-27.8
-9.7
-8.0
-5.0
-98.1
E-50
E-30
E-10
504
496
547
219
300
535
268
289
402
453
436
478
462
447
TC-50
TC-30
TC-10
AMBIENT
11.8
10.4
7.5
11.9
11.3
11.3
14.4
11.3
10.2
8.8
1.4
10.5
10.4
10.6
13.3
10.7
10.0
9.6
2.51
0.26
2.96
3.74
2.71
6.38
0.66
7.52
3.38
Dec
8.59
9.50
6.88
PPT in.
PPT cm
DO 100
DO 75
DO 35
0.06
Oct
0.15
2.26
0.55
0.82
5.74
1.40
2.08
0.7
Nov
1.78
11.8
10.1
10.1
511
9.1
223
WITHAM HILL DATA
10\ 10 \ 95
DO 20
Benton County
Site 1
10/17/95 10/24/95 10 \ 31 \95 11 \07\95
95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
9.1
Saturation (graphing)
20 cm
35 cm
75 cm
Data Lines
(graphing)
2
1
350
200
5
1.5
350
200
5
1.5
350
200
5
350
200
5
350
200
5
1.5
1.5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
76.5
69.7
78.5
79.0
2.0
Solution pH
75 cm
35 cm
20 cm
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
20.0
32.8
41.0
16.5
17.8
18.0
224
WITHAM HILL DATA
12/26/95 1/02/96
Site 1
1/12/96
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
1/26/96
-39.5
-21.5
-13.0
-14.0
-63.0
-42.5
-34.0
-30.5
-22.0
-2.0
1.0
-10.5
-58.0
-32.0
-13.5
-13.5
-27.0
-19.0
-8.0
0.0
4.0
-17.5
-11.5
-2.0
-3.5
-6.0
-14.0
-20.5
0.0
P-20-1
P-20-2
P-20-3
E-50-1
1/19/96
-25.5
-4.0
P-35-2
P-35-3
Benton County
2/02/96
-12.5
-11.5
-6.0
2109/96
2/17/96
2/23/96
3/01/96
3/08/96
369
297
394
370
288
389
367
287
389
238
383
333
261
371
351
368
256
415
399
366
376
332
359
364
380
9.3
8.6
7.4
5.8
7.7
7.5
6.7
14.3
10.3
10.7
11.9
15.0
3/01/96
3/08/96
485
368
334
389
328
305
376
334
312
410
343
336
378
245
384
337
376
212
370
217
342
349
364
279
364
308
364
310
372
300
378
318
331
330
352
8.8
7.2
4.5
2.9
9.3
9.2
8.9
12.2
10.2
9.5
8.6
8.0
9.4
8.3
8.2
9.1
7.1
5.8
D0-W100
15.4
10.1
9.3
9.2
D075-1
D075-2
D075-3
12.1
11.8
10.9
11.3
11.3
8.4
8.2
7.7
0035-1
D035-2
D035-3
12.8
10.3
D020-1
D020-2
D020-3
11.8
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
Corrected
Average
402
384
13.5
12.1
288
255
321
192
311
270
324
298
314
8.3
7.1
352
195
348
343
372
354
328
240
317
395
342
289
324
232
346
353
365
398
340
7.0
5.4
2.7
3.5
9.5
9.4
9.4
10.7
9.0
9.5
9.5
12.2
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
-39.5
-16.2
-9.8
-10.0
-63.0
-35.7
-23.0
489
490
507
425
416
467
453
521
489
475
518
481
501
TC-50
TC-30
TC-10
AMBIENT
8.8
7.2
4.5
2.9
9.3
9.2
8.9
12.2
10.2
9.5
8.6
8.0
9.4
8.3
8.2
9.1
7.1
5.8
PPT in.
0.08
1.5
Jan
1.75
3.26
4.09
3.81
4.45
480
557
0.20
473
424
311
396
12.8
8.8
8.2
8.8
8.9
E-50
E-30
E-10
DO 100
DO 75
DO 35
313
314
351
12.1
W-100
P-75
P-35
P-20
PPT cm
328
276
386
2/02/96
8.9
7.1
8.1
7.9
8.8
9.7
5.7
5.3
7.7
10.2
9.8
2/09/96
2/17/96
7.1
490
468
537
490
482
521
463
475
488
531
486
478
563
7.0
5.4
2.7
3.5
9.5
9.4
9.4
10.7
9.0
9.5
9.5
12.8
9.3
8.6
7.4
5.8
7.7
7.5
6.7
14.3
10.3
10.7
11.9
15.0
1.27
6.5
0.04
0.55
March
11.38
1.40
1.73
Feb
8.28
10.39
15.4
12.5
11.7
10.1
11.2
8.9
2/23/96
-58.0
-19.7
-14.5
-17.3
-22.0
-3.8
-1.3
-3.8
8.3
330
386
3.23
16.51
9.3
8.5
8.0
0.10
4.48
9.2
8.3
8.8
481
537
4.39
225
WITHAM HILL DATA
12/26/95
1/02/96
Site 1
1/12/96
DO 20
1/19/96
12.0
1/26/96
Benton County
2/02/96
2/09/96
2/17/96
3/01/96
3/08/96
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
6.2
2/23/96
10.0
Saturation (gr;
20 cm
35 cm
75 cm
Data Lines
(graphing)
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
3
2
2
3
2
3
2
1
1
1
1
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
Solution pH
75 cm
35 cm
20 cm
5.24
5.20
5.27
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-2
P-75-3
65.0
61.5
54.0
52.5
88.5
82.5
75.0
69.0
P-35-1
P-35-2
P-35-3
55.5
35.0
29.0
58.0
48.0
P-20-1
30.5
30.0
25.0
P-75-1
P-20-2
P-20-3
47.5
42
40
49
83.5
72.0
54.5
52.0
38
31
25
20
22
25
48.5
40.5
32.5
39.5
226
WITHAM HILL DATA
3/15/96
3/23/96
Site 1
3/30/96
4/04/96
4111196
Field Data
Benton County
4/18/96
W-100
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
353
345
395
358
362
394
362
334
389
362
334
389
254
379
320
416
254
373
222
365
327
369
383
393
222
365
327
369
383
393
13.3
13.9
16.5
24.0
-88.0
-65.0
-58.5
-58.5
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-50-1
355
E-50-2
E-50-3
281
E-30-1
378
330
394
368
324
385
370
319
390
363
470
314
356
380
370
302
395
260
378
358
419
393
349
262
379
362
423
399
342
288
368
348
398
369
339
305
369
358
400
403
293
274
402
354
227
E-10-2
E-10-3
242
367
340
403
370
370
374
353
322
393
325
353
TC-50
TC-30
TC-10
AMBIENT
9.2
9.7
11.4
17.7
10.8
10.5
10.3
10.2
9.8
10.3
12.8
10.3
10.9
10.6
18.6
12.6
12.9
11.8
10.0
12.2
12.0
10.7
9.2
11.4
11.7
11.3
11.3
E-30-2
E-30-3
E-10-1
13.1
321
311
368
371
DO-W100
5.7
D075-1
5.0
5.2
5.0
D075-2
D075-3
391
404
331
389
355
399
12.2
12.8
13.1
17.2
12.8
12.7
12.5
15.1
13.7
14.7
14.8
18.7
5/04/96
5/09/96
5/16/96
5/24/96
501
508
477
550
499
463
499
463
551
551
12.2
12.8
13.3
13.9
16.5
24.0
D035-1
D035-2
D035-3
D020-1
D020-2
D020-3
Corrected
Average
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
W-100
P-75
P-35
P-20
4/25/96
-88.0
-60.7
E-50
E-30
E-10
476
474
550
493
490
556
504
492
557
496
493
538
497
502
535
519
519
482
465
526
TC-50
TC-30
TC-10
AMBIENT
9.2
9.7
11.4
17.7
10.8
10.5
10.3
13.1
10.2
9.8
10.3
12.8
10.3
10.9
10.6
18.6
12.6
12.9
11.8
10.0
12.2
12.0
10.7
9.2
11.4
11.7
11.3
11.3
PPT in.
0.43
0.2
0.7
0.98
0.78
0.72
2.9
501
April
PPT cm
DO 100
DO 75
DO 35
1.09
0.51
1.78
476
573
13.1
12.8
12.7
12.5
17.2
15.1
13.7
14.7
14.8
18.7
0.06
0.17
1.63
2.04
0.15
0.43
4.14
5.18
May
2.49
1.98
1.83
7.37
5.7
5.1
227
WITHAM HILL DATA
3/15/96
3/23/96
Site 1
3/30/96
4/04/96
4/11/96
DO 20
Benton County
4/18/96
4/25196
5/04/96
5/09/96
5/16/96
5/24/96
350
200
350
200
5
1.5
5
1.5
Saturation (gn
20 cm
35 cm
75 cm
Data Lines
(graphing)
1
350
200
350
200
5
5
1.5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
350
200
350
200
5
1.5
5
1.5
5
350
200
5
1.5
1.5
Solution pH
75 cm
35 cm
20 cm
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
113.5
105
99.5
97
228
Benton County
Site 1
WITHAM HILL DATA
5/30/96
6/14/96
6/21/96
E-50-1
361
322
380
365
325
383
311
E-50-2
E-50-3
E-30-1
168
369
E-10-3
216
369
320
302
389
378
TC-50
TC-30
TC-10
AMBIENT
14.2
14.6
14.4
16.2
15.5
16.2
18.7
25.9
16.8
21.3
5/30/96
6/14196
6/21/96
491
460
526
495
439
432
470
442
TC-50
TC-30
TC-10
AMBIENT
14.2
14.6
14.4
16.2
15.5
16.2
18.7
25.9
15.2
16.8
21.3
PPT in.
0.11
0
0.1
6/28/96
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-30-2
E-30-3
E-10-1
E-10-2
307
308
193
287
332
357
169
382
301
298
264
343
355
347
396
358
350
402
352
346
403
140
375
347
136
381
349
362
370
287
403
184
375
353
334
291
394
15.2
242
389
176
297
346
341
273
366
291
393
16.6
16.7
16.9
25.6
16.1
331
12.8
12.3
11.4
12.0
14.6
13.2
10.8
12.1
DO-W100
0075-1
0075-2
0075-3
0035-1
0035-2
D035-3
D020-1
0020-2
0020-3
Corrected
Average
6/28/96
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
W-100
P-75
P-35
P-20
E-50
E-30
E-10
503
445
518
471
16.1
0.75
507
447
523
504
462
509
16.6
16.7
16.9
25.6
14.6
13.2
10.8
0
DO 100
DO 75
DO 35
0.28
0.25
1.91
431
496
12.1
0.39
1.37
June
PPT cm
458
0.99
3.48
2.17
Oct
1.39
5.51
3.53
0.45
Nov
1.14
229
WITHAM HILL DATA
Benton County
Site 1
5/30/96
6/14/96
6/21/96
6/28/96
350
200
5
1.5
350
200
350
200
5
1.5
1.5
350
200
5
1.5
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
DO 20
Saturation (gri
20 cm
35 cm
75 cm
Data Lines
(graphing)
Solution pH
75 cm
35 cm
20 cm
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
w-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
230
WITHAM HILL DATA
Field Data
Benton County
Site 1
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
W-100
-34.5
-18.5
-14.5
-22.5
-34.5
-19.5
-13.5
-19.5
-60.0
-43.0
-37.0
-43.0
-21.0
-9.0
-4.5
-23.0
-7.0
-6.0
-30.0
-23.5
-13.0
-11.5
-11.5
-12.5
-11.5
-12.0
306
278
291
361
327
325
399
294
292
373
313
314
341
306
290
364
193
325
334
356
323
312
209
348
369
390
338
372
173
279
338
340
284
336
8.6
7.5
5.5
6.5
8.0
7.5
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
323
230
373
320
332
356
E-30-1
150
266
341
348
269
348
163
314
329
335
338
297
11.5
10.8
10.1
10.1
8.1
10.0
5.5
316
1/11/97
-22.0
-2.0
1/20/97
-10.5
-61.5
-38.5
-33.5
-29.5
-8.0
0.0
4.0
-23.5
-15.5
1.0
-2.0
-3.5
-6.0
-21.5
337
352
386
351
240
317
395
342
289
324
215
318
362
354
353
201
9.5
9.4
9.4
10.7
8.7
8.6
8.6
9.5
351
350
395
161
186
289
310
313
319
288
345
329
350
9.5
8.9
9.3
11.6
9.7
9.4
9.3
11.8
10.3
10.2
9.9
DO-W100
8.6
7.2
9.3
9.7
D075-1
D075-2
D075-3
8.2
7.1
8.1
8.2
6.6
5.7
8.4
8.8
8.2
9.9
9.5
9.4
D035-1
D035-2
D035-3
8.9
7.8
7.7
6.8
6.2
6.7
7.1
8.1
9.5
8.8
9.1
D020-1
D020-2
D020-3
7.7
7.6
6.7
4.3
2.8
4.4
5.7
5.3
7.7
9.0
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
Corrected
Average
9.0
321
332
8.1
7.1
9.6
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
W-100
P-75
P-35
P-20
E-50
E-30
E-10
446
410
TC-50
TC-30
TC-10
AMBIENT
PPT in.
-34.5
-18.5
-11.5
-12.0
-34.5
-17.5
-12.0
-12.0
457
442
500
495
456
515
502
460
527
518
464
522
8.0
7.5
8.7
8.6
8.6
9.5
8.1
9.6
9,5
9.4
9.4
10.7
8.0
8.3
10.2
7.9
7.0
5.8
2.3
4.43
6.8
0.52
2.25
0.8
1.32
5.72
2.03
11.5
10.8
10.1
10.1
8.1
5.5
9.7
9.4
9.3
11.8
10.3
10.2
9.9
10.0
9.5
8.9
9.3
11.6
8.1
8.6
7.5
5.5
6.5
0.57
6.58
2.46
3.08
5.02
0.69
DO 100
DO 75
DO 35
16.71
6.25
1/25/97
463
475
488
476
1.45
1/20/97
7.9
7.0
5.8
2.3
457
421
489
7.1
Dec
PPT cm
8.0
8.3
10.2
487
467
536
460
445
504
9.0
1/11/97
8.1
212
318
388
378
327
353
-22.0
-3.8
-1.3
-3.8
445
491
331
336
369
382
329
363
373
363
408
-60.0
-41.0
-26.8
473
427
493
411
1/25/97
-61.5
-33.8
-19.5
-21.5
Jan
7.82
12.75
8.6
8.2
7.2
6.5
6.6
8.1
1.75
11.25
17.27
9.3
8.5
8.0
9.7
9.6
9.3
231
WITHAM HILL DATA
DO 20
Site 1
Benton County
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
7.3
3.8
6.2
1/11/97
1/20/97
9.0
1/25/97
Saturation (gri
20 cm
35 cm
75 cm
Data Lines
(graphing)
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
3
3
3
3
2
2
2
2
2
1
1
1
1
1
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
Solution pH
75 cm
35 cm
20 cm
5.78
5.87
6.12
4.54
5.55
5.81
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
no
no
no
no
no
no
60
58.5
55.5
60
59.5
54.5
61
58
P-35-1
P-35-2
P-35-3
51
53
40
33.5
38
35
P-20-1
31
P-20-2
P-20-3
30
30.5
30.5
30
31
85.5
83
78
81.5
47.5
42
40
49
87
78.5
74.5
68
38
61
31
52.5
25
20
22
25
54.5
44.5
40
350
200
5
1.5
232
WITHAM HILL DATA
2/01/97
Benton County
Site 1
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
341
341
310
325
369
314
306
314
300
336
366
297
397
323
371
323
307
386
201
204
211
341
373
365
356
199
373
207
319
352
348
289
347
Field Data
W-100
P-75-1
P-75-2
P-75-3
-48.5
-26.5
-19.5
-21.0
P-35-1
P-35-2
P-35-3
-28.5
-8.5
-4.0
P-20-1
P-20-2
P-20-3
-13.0
-11.0
-12.5
E-50-1
E-50-2
E-50-3
345
343
387
353
347
395
350
338
384
347
340
388
E-30-1
203
E-30-2
E-30-3
311
202
339
364
370
195
356
359
358
198
369
381
346
321
374
314
372
282
368
8.0
7.4
6.8
7.5
7.8
7.9
7.7
15.5
8.7
8.5
6.9
7.2
8.2
8.2
7.6
8.4
8.7
8.1
2/08/97
2/15/97
2/22/97
461
495
474
E-10-2
E-10-3
359
386
322
339
TC-50
TC-30
TC-10
AMBIENT
8.0
8.6
8.6
9.9
E-10-1
DO-W100
10.5
D075-1
10.6
10.3
9.3
D075-2
D075-3
D035-1
D035-2
D035-3
7.4
D020-2
D020-3
10.1
7.1
W-100
P-75
P-35
P-20
388
344
389
200
364
367
318
355
398
10.2
10.7
9.7
14.6
10.4
10.6
9.5
13.2
10.3
10.3
9.3
17.3
10.2
10.3
10.3
11.8
8.7
8.8
9.4
14.2
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
494
462
503
472
449
497
467
455
506
476
474
538
454
468
517
490
468
526
482
8.4
8.7
9.1
11.8
8.7
8.8
9.4
14.2
10.2
10.7
9.7
14.6
10.4
10.6
9.5
13.2
10.3
10.3
9.3
17.3
10.2
10.3
10.3
2.45
2.11
1.22
0.23
0.45
April
0.35
6.22
5.36
3.10
0.58
1.14
0.89
194
343
375
336
293
371
2/01/97
9.1
346
348
309
353
361
359
311
391
370
316
364
400
13.1
-48.5
-22.3
-13.7
-12.2
E-50
E-30
E-10
495
449
518
502
460
524
494
517
501
TC-50
TC-30
TC-10
AMBIENT
8.0
8.6
8.6
9.9
8.0
7.4
6.8
7.5
7.8
7.9
7.7
15.5
8.7
8.5
6.9
7.2
8.2
8.2
7.6
PPT in.
3.31
0.24
Feb
0.41
0.75
PPT cm
8.41
0.61
1.04
1.91
0.35
Mar
0.89
DO 100
DO 75
DO 35
311
401
10.3
9.0
9.4
D020-1
Corrected
Average
388
10.5
10.1
9.6
8.1
481
529
13.1
233
WITHAM HILL DATA
2/01197
DO 20
Site 1
Benton County
2108197
2115/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
350
200
5
1.5
350
200
5
1.5
350
200
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
8.2
Saturation (gn
20 cm
35 cm
75 cm
Data Lines
(graphing)
3
2
1
350
200
5
1.5
5
1.5
Solution pH
75 cm
35 cm
20 cm
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
no
no
no
74
66.5
60.5
59.5
58.5
39.5
33
P-20-1
31
P-20-2
P-20-3
29.5
31.5
no
no
no
234
WITHAM HILL DATA
Site 1
Benton County
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
E-50-1
E-50-2
E-50-3
326
327
406
301
327
382
305
308
384
316
330
402
327
336
419
331
E-30-1
E-30-2
E-30-3
217
360
380
326
357
396
34
360
196
356
342
314
357
211
378
371
162
219
312
142
133
297
287
348
324
270
354
204
336
360
329
362
390
11.7
12.3
12.8
17.0
12.2
12.8
14.4
25.4
12.3
12.6
13.0
14.2
13.7
14.9
16.8
27.4
15.2
16.7
19.5
29.8
15.2
15.3
15.4
11.8
16.2
16.9
17.3
21.1
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
6/01/97
E-50
E-30
E-10
490
477
529
474
346
523
469
456
517
486
470
481
389
552
514
485
498
458
530
360
561
TC-50
TC-30
TC-10
12.2
12.8
14.4
25.4
12.3
12.6
13.0
14.2
13.7
14.9
16.8
27.4
15.2
16.7
19.5
29.8
15.2
15.3
15.4
16.2
16.9
17.3
AMBIENT
11.7
12.3
12.8
17.0
11.8
21.1
PPT in.
0.68
1.88
0.68
0.11
0
0.37
Field Data
5/24/97
6/01/97
316
402
335
507
6107/97
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
171
317
357
387
386
331
449
395
359
421
DO-W100
0075-1
D075-2
D075-3
D035-1
D035-2
D035-3
0020-1
0020-2
0020-3
Corrected
Average
W-100
P-75
P-35
P-20
May
PPT cm
DO 100
DO 75
DO 35
1.73
4.78
1.73
1.58
6/07/97
1.09
June
0.28
0.94
4.01
2.77
235
WITHAM HILL DATA
Site 1
Benton County
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
6/01/97
6/07/97
350
200
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
DO 20
Saturation (gr
20 cm
35 cm
75 cm
Data Lines
(graphing)
5
1.5
1.5
Solution pH
75 cm
35 cm
20 cm
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
no
no
no
no
no
no
236
WITHAM HILL DATA
Field Data
Site 2
Benton County
10\10\95 10/17/95 10/24/95 10\31\95 11\07195 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95
12/19/95
W-100
-94.1
-94.8
-88.3
-60.5
-72.8
-60.8
-68.9
-66.9
-63.2
-14.0
-14.7
-10.9
-19.0
-13.2
-13.8
-9.4
-18.7
-13.2
P-35-1
P-35-2
P-35-3
-13.9
-10.2
-6.5
-13.1
-11.4
-9.0
-10.6
-6.1
-6.5
-12.6
-9.4
-12.2
P-20-1
P-20-2
P-20-3
-16.7
-12.2
-9.7
-18.3
-12.2
-8.4
-15.7
-11.8
-4.5
-17.8
-14.0
-7.8
384
163
379
264
216
299
266
174
-153
177
34
94
P-75-1
P-75-2
P-75-3
332
364
E-50-1
E-50-2
E-50-3
341
248
280
328
E-30-1
E-30-2
E-30-3
E-10-1
60
35
59
E-10-2
E-10-3
306
326
324
240
285
302
232
83
116
265
291
286
257
263
266
132
84
62
305
87
333
46
-151
53
4
21
-1
15
-1
11
8
-5
18
10
-2
-4
349
315
-11
-51
353
215
223
262
334
303
308
285
342
254
144
180
111
TC-50
TC-30
TC-10
AMBIENT
59
-36.2
-16.5
-20.7
-10.0
-37.9
13
-9
-83
-16
213
72
124
-73
-7
46
49
-3
148
25
25
148
158
267
-18.1
-9.1
9
11
-2
160
16
33
11.5
10.3
8
11.9
11.4
11.3
13.5
10.9
10.2
10.3
9.9
10.0
9.6
9.2
10.1
9.1
1.5
11.8
9.2
5.1
8.1
8.2
5.2
6.0
0075-1
D075-2
D075-3
4.5
4.3
9.0
4.4
2.2
4.0
5.4
1.8
2.0
3.8
1.7
0035-1
D035-2
0035-3
4.7
6.9
9.6
2.4
2.6
5.3
2.3
2.2
2.3
2.0
2.0
0020-1
D020-2
D020-3
7.2
8.3
4.9
3.8
4.0
2.8
12.1
DO-W100
Corrected
Average
-94.1
530
463
226
503
453
318
465
440
267
-94.8
-88.3
167
178
175
426
193
183
-60.5
-66.8
-68.9
415
374
489
316
411
394
TC-50
TC-30
TC-10
AMBIENT
0.06
2.26
0.55
0.82
Oct
D075
DO 35
DO 20
-14.0
-14.9
-10.2
-12.9
493
437
405
-13.2
-14.0
-10.9
-13.0
-13.2
-21.2
-8.0
-10.7
-16.5
-22.9
-11.4
-13.2
251
270
162
208
149
184
311
241
244
11.5
10.3
8.0
11.9
11.4
11.3
13.5
10.9
10.2
9.2
1.5
10.3
9.9
10.0
9.6
10.1
9.1
11.8
9.2
0.26
2.96
3.38
3.74
2.71
-65.1
12.1
PPT in.
DO 100
1.6
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
W-100
P-75
P-35
P-20
E-50
E-30
E-10
PPT cm
2.1
0.7
2.51
Nov
0.15
5.74
1.40
2.08
Dec
1.78
6.38
0.66
7.52
8.59
9.50
6.88
5.1
8.1
8.2
3.5
3.4
4.9
5.2
6.0
2.5
1.9
5.9
7.1
7.8
3.1
2.3
3.8
3.4
237
WITHAM HILL DATA
Site 2
Benton County
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
Saturation (graphing)
20 cm
35 cm
75 cm
Data Lines
(graphing)
1
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
6.3
5.5
12.4
1.5
1
3
3
3
2
2
2
3
2
1
1
1
1
350
200
5
1.5
350
200
5
1.5
350
200
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
5
1.5
41.9
2.5
17.5
33.0
9.4
14.5
91.2
70.0
78.8
65.0
92.0
71.0
80.7
65.3
92.0
66.0
81.0
45.0
88.5
63.0
80.0
43.0
26.0
30.5
35.0
26.9
32.0
30.0
29.0
35.5
35.0
27.5
31.5
28.0
3.8
9.0
12.0
2.0
9.0
13.5
5.0
9.5
18.0
2.6
7.0
14.2
Solution pH
pH 75
pH 35
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
238
WITHAM HILL DATA
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
Site 2
Benton County
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
-15.1
-15.1
-10.4
-42.7
-14.5
-18.5
-18.0
-76.5
-13.0
-17.0
-13.0
-8.5
-15.5
-8.0
-10.5
-15.0
-11.5
-13.0
-18.5
-13.0
-0.5
-3.0
-5.0
-12.5
-17.0
-12.0
-0.5
-15.5
-5.0
-12.5
-18.5
-14.0
-11.5
-18.5
-13.5
-13.5
-10.6
-15.5
-14.5
-12.0
-10.0
-14.0
-11.0
-9.5
-11.0
-7.0
-3.5
-12.5
-9.5
-6.0
-13.5
-11.0
-10.0
0.5
-2.0
-1.5
-12.5
-10.0
-6.5
-7.5
-2.0
-3.0
-13.0
-11.0
-12.0
-12.5
-11.0
-11.0
-18.3
-14.8
-12.7
-20.0
-15.0
-10.5
-19.0
-15.0
-10.0
-15.0
-12.0
-4.5
-17.5
-14.0
-7.5
-18.5
-14.5
-10.0
-6.0
-2.0
-1.5
-19.0
-14.5
-8.5
-13.5
-7.0
-3.5
-18.5
-15.0
-12.0
-18.5
-15.5
-11.0
34
-166
-53
27
64
-27
209
22
-150
-14
-9
53
-23
-97
7
9
-116
-39
-125
-155
-77
-265
-67
-86
-64
130
-43
-113
-65
-329
-66
-153
-93
-302
82
-35
-121
23
77
-59
-100
-284
-4
29
19
210
113
96
9
130
0
3
-320
-57
-3
63
-16
117
48
11
-5
-104
-45
0
-146
-93
-27
75
-29
27
260
-3
9.2
8.5
7.9
7.5
8.2
7.2
5.9
6.8
5.0
2.8
6.1
2.3
8.6
8.6
9.2
10.4
-1
-38
-23
48
-15
-29
-1
67
0
15
5
83
-127
-48
-110
60
-59
7
-41
110
8.2
8.5
9.0
12.7
8.8
8.3
7.6
7.4
3.6
6.4
13.9
8.8
9.2
10.9
17.4
291
-153
293
-15
89
282
-129
TC-50
TC-30
TC-10
AMBIENT
8.7
9.1
7.1
4.8
3.6
9.0
8.9
15.1
9.7
9.3
8.6
8.0
DO-W100
7.3
2.5
2.7
7.7
9.0
5.3
8.0
2.0
5.4
1.9
1.3
D075-1
D075-2
D075-3
8.4
2.3
6.3
5.9
2.0
6.8
2.4
9.6
1.8
5.7
2.9
4.5
5.3
6.3
7.1
5.1
4.1
1.9
2.0
2.3
1.9
4.7
1.9
0035-1
D035-2
D035-3
2.9
2.5
2.4
1.8
2.3
2.3
1.3
1.3
2.0
2.2
1.8
3.6
1.4
1.5
2.5
2.5
1.7
1.6
1.7
2.4
2.6
4.6
1.2
1.1
1.0
1.9
1.5
2.4
1.8
1.6
2.0
6.5
3.8
4.8
4.2
2.5
3.7
2.3
2.0
4.0
3.7
3.5
4.4
3.1
4.2
2.3
3.7
2.5
2.8
4.6
D020-1
D020-2
D020-3
Corrected
Average
W-100
P-75
P-35
P-20
E-50
E-30
E-10
1.8
3.1
7.4
4.7
4.4
5.8
4.5
5.5
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
-15.1
-22.7
-13.2
-15.3
-14.5
-37.7
-12.2
-15.2
-8.5
-11.8
-7.2
-10.5
-10.5
-13.3
-9.3
-13.0
-13.0
-15.8
-11.5
-14.3
-0.5
-10.3
-4.2
-8.0
-12.5
-16.3
-12.0
-15.2
-11.5
-16.0
-11.5
-15.0
137
192
216
132
135
200
208
108
184
269
-0.5
-4.0
-1.0
-3.2
37
-12.5
-14.5
-9.7
-14.0
123
199
251
-13.0
-15.0
-11.5
-14.7
60
112
186
177
111
81
314
66
52
205
82
304
93
255
6.8
5.0
2.8
2.3
8.6
8.2
8.5
9.0
12.7
8.8
8.3
7.4
3.6
7.6
8.6
9.2
10.4
8.8
9.2
10.9
17.4
1.27
6.5
0.04
4.48
0.55
March
1.73
TC-50
TC-30
TC-10
AMBIENT
8.7
9.1
7.1
9.0
8.9
PPT in.
0.08
4.8
3.6
192
195
181
9.7
9.3
8.2
7.2
5.9
4.09
110
15.1
8.6
8.0
9.2
8.5
7.9
7.5
1.5
1.75
3.26
6.1
Jan
PPT cm
DO 100
DO 75
DO 35
DO 20
7.1
192
Feb
7.1
6.4
13.9
0.20
3.81
4.45
8.28
10.39
3.23
16.51
0.10
11.38
1.40
4.39
7.3
2.5
5.1
4.1
2.1
2.7
4.0
1.5
4.4
7.7
4.6
2.5
5.3
9.0
5.7
5.3
4.3
2.2
4.0
8.0
5.4
1.7
3.9
2.0
4.6
3.2
3.5
5.4
3.7
1.3
2.5
1.9
3.0
1.3
3.3
1.8
2.7
2.6
7.4
4.7
2.1
5.0
1.8
3.4
239
WITHAM HILL DATA
Site 2
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
3
2
3
2
3
3
2
3
3
2
2
3
2
3
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
350
200
350
200
5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
26.0
68.0
61.5
Saturation (gi
20 cm
35 cm
75 cm
Data Lines
(graphing)
Benton County
12/26/95
350
200
5
1.5
5
1.5
1.5
350
200
5
350
200
5
1.5
1.5
350
200
5
1.5
2
1.5
Solution pH
pH 75
pH 35
pH 20
5.70
5.38
5.53
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
90.0
69.5
79.5
37.5
29.0
68.0
66.0
122.5
27.5
66.5
61.0
23.0
65.0
56.0
25.0
64.5
59.5
27.5
68.0
61.0
15
52.5
53
27.0
66.5
60.0
15.0
65.0
53.0
27.0
68.0
62.0
26.5
30.0
24.0
55.0
51.0
41.0
54.5
50.0
40.5
51.5
46.0
34.5
53.0
48.5
37.0
54.0
50.0
41.0
40
41
53.0
49.0
37.5
48.0
41.0
34.0
53.5
50.0
43.0
53.0
50.0
42.0
2.0
6.0
8.5
48.0
44.0
41.5
47.0
44.0
41.0
43.0
41.0
35.5
45.5
43.0
38.5
46.5
43.5
41.0
47.0
43.5
39.5
41.5
36.0
34.5
46.5
44.0
43.0
46.5
44.5
42.0
32.5
34
31
32.5
240
WITHAM HILL DATA
Benton County
Site 2
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
-16.0
-19.5
-5.5
-17.5
-20.0
-6.0
-26.5
-24.5
-24.5
-26.0
-20.5
-24.0
-47.0
-44.5
-48.5
-12.5
-22.0
-11.0
-3.5
-11.5
-5.0
-20.5
-20.5
-19.0
-41.5
-40.5
-44.0
-17.5
-28.0
-15.0
-16.0
-14.0
-12.0
P-35-2
P-35-3
-14.5
-12.0
-15.5
-13.5
-13.0
-14.5
-20.0
-21.0
-24.0
-20.0
-21.0
-23.5
-12.5
-10.0
-8.0
2.0
-5.0
-2.5
-14.5
-16.0
-22.0
-14.0
-14.0
-14.0
-12.0
-10.0
-13.0
P-20-1
P-20-2
P-20-3
-19.5
-16.0
-14.0
-18.5
-16.0
-14.0
-18.5
-14.0
-8.5
-8.5
-7.0
-4.0
-21.0
-19.0
-19.5
-16.5
-14.0
-14.0
-11.0
-12.0
E-50-1
-91
-171
-335
-160
-150
-283
-193
-273
-254
-357
-289
-201
-181
-323
50
-50
-275
-357
-250
-185
-276
62
-40
117
288
-162
-137
-250
74
-33
93
310
-332
-170
-272
-199
-10
-205
-213
-381
-204
180
76
-325
-242
-164
-217
-46
-204
-136
248
-43
-341
-154
-126
-319
87
-45
98
-136
-171
-143
-224
85
-35
125
321
-3
-141
E-50-2
E-50-3
9.7
9.5
10.2
14.2
10.3
10.8
10.9
21.1
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
E-30-1
E-30-2
E-30-3
E-10-1
-114
21
369
286
12.3
12.7
12.0
10.2
11.8
12.0
10.7
7.9
11.4
11.6
11.0
13.2
1.3
1.9
1.2
3.9
1.5
5.2
2.3
4.0
2.7
1.5
1.6
2.2
1.5
1.5
1.9
1.9
1.9
2.9
2.2
2.5
1.5
2.7
3/15/96
3/23/96
3/30/96
4/04/96
-16.0
-12.5
-14.0
-16.5
-17.5
-13.0
-13.7
-16.2
35
-26.5
-24.5
-21.7
13
120
88
370
7C-50
TC-30
TC-10
AMBIENT
9.8
10.3
11.3
14.9
10.2
10.0
DO-W100
1.2
0.8
D075-1
5.3
1.8
D035-1
D035-2
D035-3
D020-1
D020-2
D020-3
W-100
P-75
P-35
P-20
E-50
E-30
E-10
-221
171
-152
Corrected
Average
-285
74
-58
74
-25
202
-30
E-10-2
E-10-3
D075-2
D075-3
-171
341
61
85
270
10.1
13.4
322
TC-50
TC-30
TC-10
AMBIENT
9.8
10.3
11.3
14.9
10.2
10.0
13.4
9.7
9.5
10.2
14.2
PPT in.
0.43
0.2
0.7
10.1
214
69
-35
109
308
-7
13.2
13.5
12.8
17.5
12.3
12.4
12.5
17.2
13.5
14.5
14.5
18.7
13.5
13.7
16.0
23.8
1.9
2.0
1.7
1.2
1.2
4.2
2.2
3.8
1.2
5.7
2.6
5.0
2.3
4.8
2.1
5.1
2.1
2.3
1.3
2.5
1.9
1.4
1.9
2.3
2.3
2.7
2.2
2.2
4.8
1.7
1.5
2.4
2.6
2.4
2.0
1.8
1.6
4/11/96
4/18/96
4/25/96
5/04/96
-26.0
-22.3
-21.5
-47.0
-46.5
28
108
-3.5
-8.3
-1.8
-6.5
-30
334
-59
22
198
-12.5
-16.5
-10.2
-13.7
-73
40
10.3
10.8
10.9
21.1
0.98
DO 100
DO 75
DO 35
DO 20
1.09
0.51
1.2
3.6
1.8
2.4
0.8
2.7
1.6
2.1
1.78
-31
129
121
341
176
322
-109
2.0
3.0
3.2
2.4
2.3
5/09/96
5/16/96
5/24/96
-41.5
-42.3
-17.5
-21.5
-14.0
-16.7
123
-94
70
400
-91
120
239
-20.5
-19.8
-17.5
-20.0
-88
102
436
311
-16.0
-13.0
-11.7
-12.3
-79
93
304
12.3
12.7
12.0
10.2
11.8
12.0
10.7
7.9
11.4
11.6
11.0
13.2
13.2
13.5
12.8
17.5
12.3
12.4
12.5
17.2
13.5
14.5
14.5
18.7
23.8
0.78
0.72
2.9
0.06
0.17
1.63
2.04
April
PPT cm
76
97
13.5
13.7
16.0
May
2.49
1.98
1.83
7.37
0.15
0.43
4.14
5.18
1.3
3.8
2.2
1.9
1.2
1.9
1.2
3.2
2.0
2.5
2.5
1.7
1.8
2.0
4.2
2.4
1.7
3.4
3.7
3.5
1.2
3.6
1.9
2.2
3.1
3.1
241
WITHAM HILL DATA
Saturation (g1
20 cm
35 cm
75 cm
Data Lines
(graphing)
Site 2
3/15/96
3/23/96
3/30/96
4/04/96
3
2
3
2
2
2
1
1
1
1
350
200
5
1.5
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
4/11/96
Benton County
4/18/96
4/25/96
5/04/96
3
3
3
2
2
2
1
1
1
1
350
200
5
1.5
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
61.5
94
96.5
27
71.5
59
18
61
53
35
70
67
53
49
39
38.5
44
33.5
46.5
43
39.5
36.5
36
35
5/09/96
1
5/16/96
5/24/96
3
2
3
2
1
1
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
56
90
32
77.5
63
30.5
63.5
60
55
55
53
54.5
53
45
52.5
49
44
49
48
47.5
45.5
45
42
40
43
Solution pH
pH 75
pH 35
pH 20
5.85
5.92
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
30.5
69.0
53.5
32.0
69.5
54.0
74
72.5
40.5
70
72
P-35-2
P-35-3
55.0
51.0
46.5
54,0
52.0
45.5
60.5
60
55
60.5
60
54.5
P-20-1
P-20-2
P-20-3
47.5
45.0
45.0
46.5
45.0
45.0
P-75-1
P-75-2
P-75-3
P-35-1
41
92
242
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
5/30/96
6/14/96
-30.5
-28.5
-30.0
-88.5
Benton County
Site 2
WITHAM HILL DATA
6/21/96
6/28/96
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
-24.0
-27.0
-29.5
P-20-1
P-20-2
P-20-3
-322
E-30-2
E-30-3
-353
-283
-309
-305
62
-40
E-10-1
161
E-10-2
E-10-3
343
197
234
333
224
156
291
62
TC-50
TC-30
TC-10
AMBIENT
14.2
14.5
14.9
15.1
15.7
16.3
19.0
23.9
15.7
16.2
17.3
22.2
DO-W100
1.2
2.0
D075-1
D075-2
2.4
E-50-1
E-50-2
E-50-3
E-30-1
-341
-342
-108
76
316
52
-42
155
98
338
320
376
343
32
342
380
328
330
378
345
216
356
30
110
351
194
354
108
353
218
110
131
345
234
15.6
15.5
16.6
27.9
13.9
12.6
10.5
11.9
106
148
101
301
352
333
40
31
110
346
238
323
224
12.5
12.1
10.9
11.9
D075-3
D035-1
2.2
D035-2
D035-3
2.1
3.7
D020-1
D020-2
D020-3
Corrected
Average
5/30/96
6/14/96
-30.5
-29.3
-26.8
-88.5
-130
83
408
-150
272
438
240
357
344
TC-50
TC-30
TC-10
AMBIENT
14.2
14.5
14.9
15.7
16.3
19.0
23.9
15.7
16.2
17.3
22.2
PPT in.
0.11
0
0.1
W-100
P-75
P-35
P-20
E-50
E-30
E-10
15.1
6/21/96
6/28/96
DO 100
DO 75
DO 35
DO 20
1.2
535
273
402
341
401
536
342
440
15.6
15.5
16.6
27.9
13.9
12.6
10.5
11.9
0
0.39
1.37
Oct
0.25
0.28
2.4
2.7
531
0.75
June
PPT cm
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
2.0
1.91
0.99
3.48
513
343
436
2.17
Oct
1.39
5.51
3.53
0.45
Nov
1.14
243
WITHAM HILL DATA
5/30/96
Site 2
6/21/96
6/28/96
350
200
350
200
350
200
350
200
350
200
350
200
350
200
350
200
350
200
5
1.5
5
1.5
350
200
5
5
1.5
5
1.5
5
1.5
5
1.5
5
1.5
5
1.5
5
1.5
45
103
Saturation (gt
20 cm
35 cm
75 cm
Data Lines
(graphing)
1
pH 75
pH 35
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
P-75-1
78
P-75-2
P-75-3
78
P-35-1
64.5
66
60.5
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
2
Solution pH
Raw PZ Data
W-100
Benton County
6/14/96
1.5
350
200
5
1.5
244
WITHAM HILL DATA
Field Data
Site 2
Benton County
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
W-100
1/11/97
1/20/97
1/25/97
P-75-1
P-75-2
P-75-3
-15.0
-63.5
-15.5
-49.0
-18.5
-23.5
-18.5
-60.0
-13.5
-12.5
-11.0
-71.0
-11.5
-11.5
-10.0
-51.5
-18.0
-16.5
-17.0
-71.0
-8.0
-15.5
-12.0
-75.5
-0.5
-3.0
-5.0
-48.5
-17.0
-17.0
-16.0
-49.5
-6.0
-16.0
-10.0
-69.5
-10.5
-15.5
-13.0
-64.5
P-35-1
P-35-2
P-35-3
-12.5
-5.0
-5.0
-15.0
-14.5
-13.5
-13.0
-8.5
-8.0
-11.0
-8.5
-6.5
-14.5
-14.5
-13.5
-12.5
-11.0
-9.0
0.5
-2.0
-1.5
-15.0
-14.0
-13.5
-12.5
-10.5
-8.0
-12.5
-11.0
-7.0
P-20-1
P-20-2
P-20-3
-8.5
-3.5
-6.5
-18.5
-15.0
-13.5
-14.5
-9.0
-9.0
-12.0
-7.5
-8.0
-19.5
-15.5
-14.0
-17.5
-11.0
-9.5
-6.0
-2.0
-1.5
-19.0
-15.5
-14.5
-15.0
-11.0
-9.5
-16.5
-10.5
-9.0
269
313
306
90
127
307
238
287
212
284
283
277
129
112
-10
7
-43
-319
-75
-35
-80
-309
-68
-52
-144
148
200
-59
-100
-284
-4
29
13
-15
-9
-360
-102
47
-3
265
237
49
-13
160
294
160
48
37
-25
59
85
85
220
280
172
9.9
9.3
10.1
10.0
5.1
8.6
8.8
11.7
9.7
9.4
9.3
11.8
9.5
9.0
8.6
7.3
8.0
8.6
7.7
DO-W100
8.3
4.6
3.0
3.3
0075-1
D075-2
D075-3
9.5
9.2
8.5
5.3
5.8
7.0
6.2
5.2
D035-1
D035-2
8.3
7.8
9.5
3.5
1.8
5.0
8.5
7.8
7.6
6.8
4.3
6.3
E-50-1
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
309
262
310
55
111
312
256
266
138
11.0
10.6
61
19
122
302
175
19
210
81
113
96
7.6
6.9
6.8
9.7
8.6
8.6
9.2
10.4
8.7
8.2
1.9
6.5
4.5
7.7
158
10.1
8.0
1.7
6.1
5.5
5.7
4.9
6.0
4.5
5.3
6.3
6.8
4.6
4.3
3.7
4.1
2.1
2.4
5.2
5.3
2.0
2.1
2.1
1.7
1.6
1.7
2.1
1.5
1.5
4.5
1.7
1.5
1.8
0.5
1.4
1.8
1.6
5.8
5.0
4.9
4.0
4.2
4.9
3.7
4.6
8.3
3.7
3.5
4.4
5.6
3.0
5.4
4.2
2.6
3.9
4.8
4.3
6.6
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
1/25/97
-6.0
-31.8
-10.3
-11.8
57
158
358
-10.5
-31.0
-10.2
-12.0
54
8.1
7.3
7.2
7.2
9.2
10.1
7.5
6.5
5.7
2.0
0.52
2.25
0.8
17.27
1.32
5.72
2.03
8.0
5.4
1.7
3.9
1.7
6.1
5.2
1.7
3.7
2.4
5.5
3.9
1.6
4.7
3.6
5.2
-15.0
-42.7
-7.5
-6.2
1.6
1.1
4.9
7.6
-13.5
-31.5
-9.8
-10.8
205
254
399
-11.5
-24.3
-8.7
-9.2
95
216
403
-18.0
-34.8
-14.2
-16.3
9.7
9,4
9.3
8.0
11.8
9.5
9.0
8.6
7.3
3.08
5.02
TC-50
TC-30
TC-10
AMBIENT
11.0
10.6
10.1
9.9
8.6
7.7
10.0
5.1
9.3
8.6
8.8
11.7
PPT in.
0.57
6.58
2.46
352
420
9.0
7.1
-18.5
-34.0
-14.3
-15.7
466
355
379
481
-8.0
-34.3
-10.8
-12.7
43
90
318
-0.5
-18.8
-1.0
-3.2
37
192
314
-17.0
-27.5
-14.2
-16.3
8.6
8.6
9.2
10.4
8.7
8.2
4.9
7.6
7.6
6.9
6.8
9.7
0.69
4.43
6.8
66
179
374
7.1
Dec
DO 100
DO 75
DO 35
DO 20
-5
156
194
32
9.2
478
337
395
PPT cm
21
8.1
0020-2
0020-3
E-30
E-10
1
77
36
240
286
-31
-349
-57
7.5
6.5
5.7
2.0
D020-1
W-100
P-75
P-35
P-20
E-50
-264
-22
-353
-95
27
40
80
268
60
7.3
7.2
7.2
0035-3
Corrected
Average
291
5
1.45
6.25
7.82
12.75
1.75
8.3
4.6
6.0
3.4
5.8
3.0
6.8
1.5
5.2
3.3
6.2
1.3
1.9
5.5
4.4
5.5
8.5
8.0
164
302
Jan
16.71
9.1
64
168
311
1.5
1.3
2.1
11.25
245
WITHAM HILL DATA
Saturation (gi
Benton County
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
20 cm
35 cm
75 cm
Data Lines
(graphing)
Site 2
350
200
5
1.5
1/11/97
1/20/97
1/25/97
3
2
3
3
3
3
3
2
2
2
2
3
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
350
200
5
1.5
350
200
350
200
5
1.5
350
200
5
350
200
5
350
200
5
350
200
350
200
350
200
350
200
5
1.5
1.5
1.5
5
1.5
5
1.5
1.5
5
1.5
5
1.5
2
Solution pH
pH 75
pH 35
pH 20
6.10
6.22
6.18
6.09
5.86
5.76
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
no
no
no
29.5
113
63.5
95
33
73
66.5
106
28
62
59
117
58
97.5
53
44
36
55.5
53.5
44.5
53.5
47.5
39
36.5
32.5
37.5
46.5
44
44.5
42.5
38
40
32.5
66
65
no
no
no
117
22.5
65
60
121.5
51.5
47.5
37.5
55
53.5
44.5
53
50
40
40
36.5
39
47.5
44.5
45
45.5
40
40.5
26
61
15
52.5
53
94.5
40
41
32.5
34
31
32.5
31.5
66.5
64
95.5
20.5
65.5
58
115.5
110.5
55.5
53
44.5
53
49.5
39
53
50
38
47
44.5
45.5
43
40
40.5
44.5
39.5
40
25
65
61
246
WITHAM HILL DATA
Site 2
Benton County
2101/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
-2.5
-10.5
-9.0
-69.0
-16.0
-16.0
-16.0
-73.0
-18.0
-16.5
-18.0
-75.5
-18.5
-17.5
-18.0
-73.5
-6.5
-18.0
-12.5
-64.5
-9.5
-16.0
-12.0
-71.0
-13.0
-14.5
-11.0
-75.0
-14.5
-16.5
-15.5
-72.5
-19.5
-17.0
-17.5
-61.0
-26.0
-20.0
-25.0
-73.5
-35.5
-28.5
-33.0
-10.0
-7.5
-5.5
-15.5
-14.0
-13.0
-15.5
-14.5
-15.5
-15.0
-14.0
-15.0
-13.0
-6.0
-4.5
-13.0
-8.0
-4.5
-14.5
-9.5
-9.5
-15.0
-14.0
-13.0
-15.5
-15.0
-16.0
-20.5
-22.0
-24.0
-29.5
-31.5
-32.5
P-20-2
P-20-3
-13.0
-8.0
-6.0
-18.0
-13.5
-13.0
-19.0
-14.5
-15.0
-18.0
-14.5
-15.0
-14.5
-8.0
-4.0
-16.5
-9.5
-6.0
-17.0
-12.5
-9.5
-18.5
-13.5
-13.0
-19.0
-15.5
-16.0
E-50-1
-32
0
-70
-35
-367
-204
43
-37
-29
-373
-203
48
-28
55
-95
-55
-366
-318
55
-40
132
-110
-14
-347
-74
-3
-26
48
-70
-38
-406
-195
-73
-52
-399
-246
-111
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
16
-31
-157
-74
-272
-339
99
-32
-33
191
0
-8
-37
128
18
65
-61
-27
188
14
22
-166
-15
-383
-324
-57
-47
112
32
-51
-92
-263
-78
-206
-340
42
-42
37
122
102
8.2
8.4
14.0
9.6
9.5
8.9
16.6
9.6
9.4
9.2
9.7
17.1
9.4
9.5
9.5
14.3
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
-337
-88
53
10
-45
-355
-182
151
190
143
-31
170
121
37
85
112
173
127
TC-50
TC-30
TC-10
AMBIENT
8.0
8.2
8.4
9.7
7.3
6.9
6.0
9.2
7.2
7.2
7.2
14.8
7.9
7.5
6.6
8.5
7.8
7.6
8.2
8.0
7.6
8.3
12.4
DO-W100
7.7
1.9
0.8
1.2
4.3
2.0
1.2
0.8
0.9
0.9
1.0
0075-1
0075-2
0075-3
3.1
3.9
2.3
7.8
4.2
2.5
10.3
4.8
1.8
5.4
2.0
3.9
4.8
2.7
9.5
5.1
5.7
5.1
2.1
9.6
2.5
9.6
2.5
10.6
5.4
2.4
9.2
6.1
2.4
D035-1
1.3
1.4
1.4
2.6
1.8
1.0
3.4
2.1
2.8
2.0
1.7
2.0
1.0
1.7
2.1
2.2
1.2
1.2
1.9
1.3
1.1
1.5
1.2
1.6
1.1
0035-2
0035-3
2.0
2.8
4.3
0020-1
D020-2
D020-3
2.8
2.5
3.4
2.7
4.5
4.0
2.6
4.4
2.3
3.9
1.9
1.9
3.2
1.9
2.0
2.0
2.1
2.5
3.5
3.7
5.3
5.2
3.3
2.2
2.4
2.4
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
-2.5
-29.5
-7.7
-9.0
62
-18.0
-36.7
-15.2
-16.2
38
117
294
-18.5
-36.3
-14.7
-15.8
-6.5
-31.7
-7.8
-8.8
-14.5
-34.8
-14.0
-15.0
-19.5
-31.8
-15.5
-16.8
-26.0
-39.5
-22.2
-35.5
-30.8
-31.2
13
28
143
212
-9.5
-33.0
-8.5
-10.7
13
108
-13.0
-33.5
-11.2
-13.0
166
298
-16.0
-35.0
-14.2
-14.8
27
114
300
2
64
262
8.0
8.2
8.4
9.7
7.3
6.9
6.0
9.2
7.2
7.2
7.2
7.8
7.6
14.8
7.9
7.5
6.6
8.5
PPT in.
3.31
0.41
0.75
PPT cm
8.41
0.24
Feb
0.61
1.04
7.7
1.9
4.7
1.3
2.6
4.7
1.4
E-10-1
E-10-2
E-10-3
Corrected
Average
W-100
P-75
P-35
P-20
E-50
E-30
E-10
TC-50
TC-30
TC-10
AMBIENT
DO 100
DO 75
DO 35
DO 20
-1
2.0
9.0
1.4
4.2
1.1
8.1
77
319
7.1
1.1
139
8.1
9.4
9.6
8.9
1.0
2.1
-61
24
62
1.9
10
14
-3
17
88
214
156
249
35
206
77
173
8.2
9.6
9.4
9.2
9.7
9.6
8.0
7.6
8.3
12.4
14.0
9.4
9.6
8.9
16.6
0.35
Mar
2.45
2.11
1.22
0.23
1.91
0.89
6.22
5.36
3.10
0.58
0.8
1.2
1.4
3.7
1.4
3.8
0.8
5.8
1.7
0.9
5.7
1.5
3.5
2.0
5.7
1.6
2.4
0.9
4.9
4.3
3.8
1.2
5.7
1.6
2.1
2.8
7.1
8.2
8.1
8.4
6.0
1.8
2.5
2.1
9.4
9.5
9.5
9.5
14.3
8.9
17.1
0.35
0.45
April
1.14
6.1
0.89
1.0
.
3.8
3.0
247
WITHAM HILL DATA
2/01/97
Site 2
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
3
Saturation (gi
20 cm
35 cm
75 cm
Data Lines
(graphing)
Benton County
2/08/97
3
3
3
2
3
2
3
2
2
2
3
2
2
3
2
3
2
2
2
1
1
1
1
1
1
1
1
1
1
1
350
200
350
200
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
5
1.5
5
1.5
350
200
5
350
200
5
350
200
5
1.5
1.5
350
200
5
1.5
350
200
5
1.5
350
200
5
1.5
1.5
Solution pH
pH 75
pH 35
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
yes
yes
yes
17
yes
yes
no
30.5
65.5
64
119
32.5
66
66
121.5
33
67
66
119.5
67.5
60.5
110.5
55.5
53
46
46
43.5
46
P-75-3
60
57
115
P-35-1
P-35-2
P-35-3
50.5
46.5
36.5
56
53
44
56
53.5
46.5
P-20-1
41
P-20-2
P-20-3
37
37
46
42.5
44
47
43.5
46
24
65.5
60
27.5
64
59
117
53.5
45
35.5
42.5
37
21
35
34
66.5
65.5
107
40.5
69.5
73
119.5
50
78
121
29
66
63.5
118.5
53.5
47
35.5
55
48.5
40.5
55.5
53
44
56
54
47
61
70
70.5
63.5
44.5
38.5
37
45
41.5
40.5
46.5
42.5
44
47
44.5
47
61
55
81
248
WITHAM HILL DATA
Site 2
Benton County
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
6/01/97
-38.0
-33.5
-37.0
-17.5
-16.0
-16.0
-70.5
-18.5
-17.5
-18.5
-67.5
-53.0
-42.0
-49.5
-74.5
-66.0
-71.0
-99.5
-60.5
P-35-1
P-35-2
P-35-3
-12.0
-14.0
-16.0
-16.0
-10.5
-17.0
P-20-1
P-20-2
P-20-3
-18.0
-14.5
-15.5
-19.0
-16.0
-17.0
-300
-89
-185
-343
-12
-53
-313
-97
-382
-383
-53
-62
137
-303
-109
342
321
248
-330
110
32
68
133
-341
177
-60
390
256
124
Field Data
W-100
P-75-1
P-75-2
P-75-3
E-50-1
E-50-2
E-50-3
E-30-1
E-30-2
-274
-66
-182
-349
-311
-66
-365
-366
49
E-30-3
-41
153
168
118
49
-65
E-10-1
E-10-2
E-10-3
163
168
-113
TC-50
TC-30
TC-10
AMBIENT
10.7
11.6
11.9
15.3
11.4
DO-W100
0075-1
0075-2
0075-3
3.1
168
-56
118
12.1
11.5
11.8
12.8
22.6
12.1
14.1
0.9
0.8
4.8
92
13.2
14.3
15.5
-381
-353
-163
265
141
15.1
-65.0
41
15.1
15.1
120
201
347
251
82
119
16.4
16.8
17.4
20.6
28.2
16.2
17.9
27.7
1.2
1.9
2.0
6.7
5.3
2.8
7.2
5.3
1.8
5.6
6.1
3.7
5.6
4.3
7.3
0035-2
0035-3
1.3
1.5
2.2
1.4
1.3
1.5
0020-1
2.1
0020-2
1.5
2.6
2.2
1.6
4.0
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
6/01/97
W-100
P-75
P-35
P-20
E-50
E-30
E-10
-38.0
-35.3
-17.5
-34.2
-14.0
-16.0
-63
50
247
-18.5
-34.5
-14.5
-17.3
-7
42
-53.0
-45.8
-74.5
-68.5
-99.5
-60.5
-65.0
-79
251
288
-80
94
255
229
347
315
264
400
325
TC-50
TC-30
TC-10
AMBIENT
10.7
11.6
11.9
15.3
11.4
11.5
11.8
13.2
14.3
15.5
28.2
15.1
15.1
15.1
16.4
16.8
17.4
PPT in.
0.68
1.88
PPT cm
1.73
4.78
0.9
4.0
0.8
D035-1
D020-3
Corrected
Average
DO 100
DO 75
DO 35
DO 20
11
64
321
12.1
12.8
22.6
5.1
1.7
2.1
12.1
14.1
0.68
May
1.73
1.2
4.2
1.4
2.6
12
0.11
16.2
17.9
27.7
0
0.28
1.9
4.9
2.0
5.0
6/07/97
15.2
12.3
15.2
12.3
6/07/97
20.6
0.37
1.58
June
1.09
0.94
4.01
2.77
6.7
7.3
249
WITHAM HILL DATA
4/18/97
Site 2
4/26/97
5/03/97
3
3
2
2
1
1
5/10/97
5/16/97
5/24/97
6/01/97
6/07/97
350
200
5
1.5
350
200
350
200
350
200
5
1.5
5
1.5
5
1.5
Saturation (gi
20 cm
35 cm
75 cm
Data Lines
(graphing)
1
350
200
5
1.5
350
200
350
200
Benton County
1
350
200
5
5
5
1.5
1.5
1.5
Solution pH
pH 75
pH 35
pH 20
6.24
6.01
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
yes
yes
yes
52.5
83
85
no
yes
yes
32
65.5
64
116.5
33
67
66.5
113.5
52.5
53
47
56.5
49.5
48
46
43.5
46.5
47
45
48
67.5
91.5
97.5
89
115.5
119
114
75
113
250
WITHAM HILL DATA
Field Data
W-100
Site 3
Benton County
10 \ 10 95 10/17/95 10/24/95 10 \ 31\95 11\07 95 11/14/95 11/21/95 11/28/95
12/05/95 12/12/95 12/19/95
-49.1
P-75-1
-59.2
-72.8
P-75-2
P-75-3
P-35-1
-5.7
-34.1
-3.8
-23.7
-63.4
-72.8
-2.8
-29.3
-44.0
-56.5
-4.7
-28.4
-43.1
-55.2
P-35-2
P-35-3
-9.6
-4.0
-8.3
-5.9
-0.3
-6.6
-5,7
-0.5
-4.0
-10.9
-4.8
-7.8
P-20-1
-1.9
-0.3
-1.0
-6.2
-0.6
-0.2
-3.6
-3.6
-7.9
P-20-2
P-20-3
-2.1
-7.1
E-50-1
376
349
53
38
221
16
E-30-1
335
46
E-30-2
E-30-3
331
31
329
335
338
333
46
55
29
E-50-2
E-50-3
319
269
232
50
63
326
293
255
5
2
321
319
279
-18
419
376
476
339
370
331
4
93
35
260
-97
19
-6
-59
87
220
8
-8
-3
521
343
-11
-19
291
5
2
66
81
18
391
-1
21
13.1
208
-33
23
39
11.8
11.4
11.5
14.2
-16
-13
-1
-1
484
406
10.8
9.6
8.6
1.6
9.3
10.8
12
8
-4.1
-7
-8
0
11.1
-40
-10
-29
-9
15
-8
9.8
9.3
9.0
9.7
7.0
5.5
5.6
9.9
10.9
9.3
9.3
8.4
8.6
D035-1
D035-2
D035-3
8.3
9.8
9.4
3.2
4.0
1.8
1.8
2.1
1.6
1.5
1.5
0020-1
D020-2
0020-3
5.7
2.8
4.0
2.5
4.7
2.1
2.9
2.0
3.8
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
19
-1
256
266
258
243
-23
8
11.8
11.2
9.7
DO-W100
0075-1
0075-2
16
28
14
D075-3
Corrected
Average
10 \ 10 95 10/17/95
10/24/95
10 \ 31 \ 95 11 \ 07 \ 95
W-100
-49.1
472
493
503
192
202
202
430
452
474
198
163
167
551
631
563
365
458
423
TC-50
TC-30
TC-10
AMBI ENT
PPT in.
0.06
2.26
0.55
0.82
Oct
PPT cm
DO W100
DO 75
DO 35
DO 20
0.7
2.51
-59.2
-72.8
-5.7
-7.3
-3.7
-3.8
-53.3
-4.2
-2.5
-2.8
-43.2
-3.4
-1.5
-4.7
-42.2
-7.8
-5.2
154
163
170
267
279
177
137
148
187
155
143
104
151
11.8
11.2
9.7
10.8
9.6
8.6
1.6
10.0
9.8
10.5
13.1
11.8
11.4
11.5
14.2
11.1
9.8
9.3
9.0
9.7
0.26
2.96
3.38
3.74
2.71
-34.1
Nov
0.15
5.74
1.40
2.08
1.7
2.5
11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
P-75
P-35
P-20
E-50
E-30
E-10
5.1
-33
-37
-55
-98
10.0
9.8
10.5
135
167
Dec
1.78
6.38
0.66
7.52
8.59
9.50
6.88
9.3
10.8
9.9
7.0
10.9
9.2
4.3
4.1
5.5
9.3
1.9
3.7
2.1
5.6
8.5
1.5
2.9
251
WITHAM HILL DATA
Benton County
Site 3
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
Saturation (graphing)
20 cm
35 cm
75 cm
Data Lines
(graphing)
3
1
350
200
5
350
200
5
350
200
5
350
200
350
200
5
5
3
2
3
2
3
2
1
1
1
1
2
350
200
5
350
200
5
350
200
350
200
350
200
5
5
5
350
200
5
54.0
43.2
2.5
100.0
102.0
59.5
13.5
2.5
103.0
53.0
36.0
21.5
101.0
54.0
37.0
23.0
29.5
36.0
31.0
33.8
40.3
33.0
34.0
40.0
36.0
28.0
35.0
31.5
21.0
20.8
15.0
22.8
22.0
16.0
22.5
23.0
19.0
18.5
19.0
14.0
Solution pH
pH 75
pH 35
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
47.4
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
252
WITHAM HILL DATA
Site 3
Benton County
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
-13.7
-37.9
-47.4
-51.7
-9.0
-37.0
-46.0
-57.5
-8.0
-33.5
-43.0
-55.0
-1.0
-39.5
-49.5
-58.0
-1.0
-39.0
-50.0
-57.0
-13.5
-42.0
-51.0
-59.0
1.0
-24.0
-34.0
-46.0
-3.0
-30.0
-39.0
-51.5
1.0
-44.5
-52.5
-60.0
-15.0
-47.0
-54.0
-62.5
-10.0
-46.0
-55.0
-62.0
-17.8
-14.3
-17.8
-16.0
0.0
-9.5
-15.5
-8.0
-9.5
-9.5
-1.0
-3.5
-10.5
-3.0
-5.5
-19.5
-14.5
-12.5
-5.5
0.0
-1.5
-12.0
-3.5
-6.5
-7.5
-1.0
-2.5
-20.0
-15.0
-14.5
-17.0
-11.0
-11.5
-13.5
-12.2
-14.0
-7.0
-8.5
-11.0
-7.0
-8.5
-10.5
-1.0
-2.0
-5.0
-2.0
-3.0
-6.5
-11.5
-14.5
-12.5
1.0
-1.0
-2.5
-4.0
-4.5
-8.5
0.0
-1.5
-4.0
-13.5
-16.5
-14.0
-9.5
-12.0
-11.5
-18
-23
4
-9
-15
-7
-21
-20
-36
-22
-26
-43
-30
-31
-37
-18
-27
13
-14
-145
-53
-76
-23
-58
-39
-40
-46
-54
-38
-40
-50
E-30-1
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
-50
-72
-17
-34
-73
-68
-39
-159
-34
-249
-285
-93
-344
-307
-238
-112
-98
-53
-364
-41
-133
8.0
6.4
3.5
4.3
8.1
8.1
-103
-86
-56
-354
-153
-120
8.3
-99
-88
-52
-351
-202
8.6
4.5
2.2
3.4
8.3
8.9
10.5
7.9
7.2
6.7
6.5
6.1
-102
8.6
8.0
7.7
7.4
-47
-63
-43
-236
-67
-70
7.5
6.9
5.7
6.2
-45
-17
-44
-45
-54
-63
TC-50
TC-30
TC-10
AMBIENT
-20
-5
36
-3
8.6
8.6
8.9
13.8
-74
-345
-32
-89
DO-W100
7.9
4.6
4.2
7.7
5.5
7.1
8.7
8.7
8.6
12.0
10.5
10.9
6.6
8.3
8.6
7.1
3.5
3.3
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
-41
7
31
16
-22
5
-221
-93
9.3
8.9
8.5
-55
-61
-33
-281
-58
-31
6.1
13.0
8.0
7.2
4.8
13.9
8.7
11.0
17.6
3.1
2.4
2.2
3.6
4.4
9.4
8.3
9.4
7.3
7.5
7.7
6.7
6.0
6.4
1.2
1.9
1.4
2.5
3.9
2.6
2.1
2.1
2.1
1.9
2.5
2.5
D075-1
11.1
D075-2
D075-3
10.7
10.6
D035-1
D035-2
D035-3
2.6
3.4
3.3
2.4
2.9
3.3
1.8
3.4
2.6
6.0
5.2
5.2
2.4
3.5
3.2
D020-1
D020-2
D020-3
3.6
3.1
4.2
4.7
3.3
3.6
3.7
3.7
3.7
3.6
5.5
5.5
2.6
2.2
2.5
3.6
4.2
3.1
2.4
2.2
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
-13.7
-45.7
-16.6
-13.2
-9.0
-46.8
-8.5
-8.8
-8.0
-43.8
-11.0
-8.7
-1.0
-49.0
-4.7
-2.7
-1.0
-48.7
-6.3
-3.8
-13.5
-50.7
-15.5
-12.8
1.0
E-50
E-30
E-10
144
115
186
146
129
177
144
130
101
33
69
123
110
43
128
11
TC-50
TC-30
TC-10
AMBIENT
8.0
6.4
3.5
8.6
8.6
8.9
13.8
9.3
8.9
8.5
6.1
8.6
8.0
7.7
7.4
7.5
6.9
5.7
6.2
1.5
1.75
3.26
4.09
Corrected
Average
W-100
P-75
P-35
P-20
PPT in.
4.3
0.08
Jan
9.0
9.3
8.5
2.4
2.5
2.8
4.0
3.6
2.5
2.3
2.4
2/17/96
2/23/96
3/01/96
3/08/96
-3.0
-40.2
-7.3
-5.7
1.0
-34.7
-2.3
-0.8
-52.3
-3.7
-1.8
-15.0
-54.5
-16.5
-14.7
-10.0
-54.3
-13.2
-11.0
65
-48
-129
116
79
110
44
147
126
114
-41
-30
114
73
-78
6.1
8.1
8.1
4.5
2.2
3.4
8.3
8.9
10.5
7.9
8.5
13.0
8.3
8.0
7.2
4.8
7.2
6.7
6.5
13.9
1.27
6.5
0.04
4.48
3.1
111
0.20
3.81
4.45
8.28
10.39
3.23
16.51
0.10
DO W100
DO 75
DO 35
DO 20
7.9
10.8
3.1
4.6
4.2
8.7
7.7
5.5
7.8
3.0
2.4
7.1
3.1
11.1
8.5
3.3
3.6
9.0
1.5
2.2
2.4
7.5
3.0
2.4
2.6
3.7
5.5
4.9
5.3
5.5
3.5
Feb
2.9
3.3
5.5
2.0
3.0
2.4
PPT cm
4.2
-241
2.2
2.5
81
0.55
March
11.38
1.40
2.2
6.4
2.3
2.3
3.6
6.0
2.5
3.5
1.6
1.6
8.6
8.7
11.0
17.6
1.73
4.39
4.4
5.4
2.2 .
2.4
253
Site 3
WITHAM HILL DATA
Benton County
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2117/96
2/23196
3101/96
3
2
3
2
3
3
3
2
3
2
3
2
3
2
3
2
3
2
3
2
2
2
1
1
1
1
1
1
1
1
1
1
1
350
200
5
350
200
350
200
350
200
350
200
350
200
350
200
5
350
200
5
5
5
5
5
350
200
5
25.0
92.5
103.5
105.0
41.0
95.0
105.0
107.5
36.0
94.0
106.0
107.0
3/08/96
Saturation (gr.;
20 cm
35 cm
75 cm
Data Lines
(graphing)
350
200
5
5
350
200
5
Solution pH
pH 75
pH 35
pH 20
5.45
5.41
5.5
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-2
P-75-3
91.5
43.0
32.0
27.0
35.0
85.0
97.0
102.5
34.0
81.5
94.0
100.0
27.0
87.5
100.5
103.0
27.0
87.0
101.0
102.0
39.5
90.0
102.0
104.0
25
72
85
91
29.0
78.0
90.0
96.5
P-35-1
P-35-2
P-35-3
20.0
24.0
20.0
54.5
40.0
50.0
54.0
48.0
50.0
48.0
41.0
44.0
49.0
43.0
46.0
58.0
54.5
53.0
44
40
42
50.5
43.5
47.0
46.0
41.0
43.0
58.5
55.0
55.0
55.5
51.0
52.0
P-20-1
7.5
9.0
7.0
37.5
36.5
39.0
37.5
36.5
38.5
31.5
30.0
33.0
32.5
31.0
34.5
42.0
42.5
40.5
29.5
29
30.5
34.5
32.5
36.5
30.5
29.5
32.0
44.0
44.5
42.0
40.0
40.0
39.5
P-75-1
P-20-2
P-20-3
254
WITHAM HILL DATA
Site 3
Benton County
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
P-75-2
P-75-3
-22.0
-50.0
-56.5
-64.0
-14.0
-56.0
-61.5
-68.0
-24.0
-58.5
-62.0
-69.0
-21.0
-47.0
-55.0
-64.5
-42.0
-63.0
-64.5
-72.5
-2.0
-52.0
-57.5
-67.5
-3.0
-47.0
-56.5
-65.0
-40.0
-56.0
-60.0
-68.0
-58.0
-72.5
-71.0
-78.0
-11.0
-68.0
-70.5
-76.5
-11.0
-47.0
-56.5
-62.5
P-35-1
P-35-2
P-35-3
-26.5
-22.0
-22.0
-19.5
-15.5
-17.0
-28.5
-25.0
-27.5
-26.5
-23.0
-25.0
-8.5
-3.5
-8.5
-7.0
-2.5
-7.5
-18.5
-11.5
-13.5
-16.5
-10.0
-14.5
P-20-1
-18.5
-20.0
-21.0
-12.5
-18.5
-17.0
-3.5
-5.5
-9.0
-3.5
-5.0
-8.5
-8.5
-10.0
-16.0
-7.5
-10.0
-16.5
-42
-34
-43
-38
-47
-47
-45
-50
-57
-33
-32
-35
-176
-44
-232
-63
-29
-38
-39
-44
-40
-41
6
-66
-43
-8
-19
-138
-123
-120
-111
-62
-102
-86
-49
-270
-258
-263
-149
-115
-72
-81
-91
-291
-6
-269
-262
-69
9.4
-59
-50
-26
-16
-22
12.1
-112
-69
-49
-97
-38
-233
11.7
-104
-76
-372
-85
-139
9.8
10.0
11.5
15.1
12.1
-86
-80
-36
-27
-153
-109
10.3
10.3
10.7
21.0
12.3
11.4
9.9
DO-W100
2.0
2.4
1.6
D075-1
D075-2
D075-3
5.2
5.4
4.8
4.7
5.5
5.2
5.0
D035-1
2.5
3.7
2.5
1.4
3.1
1.9
1.4
2.8
2.7
2.9
1.7
1.5
4.6
1.4
1.7
1.5
1.7
2.5
2.3
3.0
4.3
3.6
2.6
Field Data
W-100
P-75-1
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
0035-2
D035-3
-91
-151
10.2
9.8
10.0
9.8
12.5
3.7
D020-1
1.9
0020-2
0020-3
4.9
Corrected
Average
9.1
-54
131
-41
147
-19
-21
-41
-45
-23
171
12.4
16.9
189
99
177
12.6
12.6
12.8
18.9
14.1
11.6
10.4
10.0
-25
-48
-123
11.4
11.5
11.2
13.2
14.8
15.0
18.3
-99
-98
-78
-39
-55
-53
13.5
13.4
16.4
23.6
1.9
2.0
1.5
2.7
1.4
2.9
1.8
4.7
4.8
4.0
3.9
3.8
5.4
4.9
6.0
6.2
6.9
1.2
2.6
2.7
5.1
2.4
4.1
2.9
-71
80
-338
183
109
13.1
13.1
4.1
4.1
1.9
1.9
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
-22.0
-56.8
-23.5
-19.8
-14.0
-61.8
-17.3
-16.0
-24.0
-63.2
-27.0
-21.0
-55.5
-24.8
-42.0
-66.7
-2.0
-59.0
-6.8
-6.0
-3.0
-56.2
-5.7
-5.7
-40.0
-61.3
-58.0
-73.8
-11.0
-71.7
-14.5
-11.5
-11.0
-55.3
-13.7
-11.3
117
106
82
123
94
45
243
99
323
142
98
146
121
71
.115
87
102
110
58
55
6
-103
58
113
84
-31
112
63
-69
TC-50
TC-30
TC-10
AMBIENT
9.8
10.0
11.5
10.2
9.8
10.0
9.4
12.1
12.1
9.8
12.5
12.3
11.4
9.9
11.7
11.6
10.4
10.0
11.4
11.5
11.2
13.2
12.4
16.9
12.6
12.6
12.8
18.9
14.1
14.8
15.1
10.3
10.3
10.7
21.0
15.0
18.3
13.5
13.4
16.4
23.6
PPT in.
0.43
0.2
0.7
0.98
0.78
0.72
2.9
0.06
0.17
1.63
2.04
7.37
0.15
0.43
4.14
5.18
1.5
2.7
1.4
W-100
P-75
P-35
P-20
E-50
E-30
E-10
44
9.1
April
PPT cm
DO W100
DO 75
DO 35
DO 20
1.09
0.51
2.0
2.4
5.0
2.7
3.6
5.2
2.9
1.78
322
13.1
13.1
69
119
May
2.49
1.98
1.83
1.6
1.9
5.2
2.5
4.8
2.0
4.5
2.0
1.5
2.9
1.8
3.9
5.4
6.4
1.8
2.0
4.1
3.1
3.2
2.7
255
WITHAM HILL DATA
Benton County
Site 3
3/15/96
3/23/96
3/30/96
4/04/96
3
2
3
2
2
2
1
1
1
1
350
200
5
350
200
5
350
200
5
4/11/96
4/18/96
4/25/96
3
2
1
1
5/04/96
5/09/96
5/16/96
5/24/96
3
3
2
2
3
2
1
1
Saturation (gr:
20 cm
35 cm
75 cm
Data Lines
(graphing)
350
200
5
1
350
200
350
200
350
200
5
5
5
68
28
100
108.5
112.5
29
95
107.5
110
47
43.5
49
34
33.5
37
1
1
350
200
5
350
200
5
66
104
84
120.5
122
123
350
200
5
350
200
37
121.5
121.5
37
95
107.5
107.5
45.5
42.5
48
57
51.5
54
55
50
55
34
33
36.5
39
38
38
38
44
44.5
5
Solution pH
pH 75
pH 35
pH 20
5.23
6.03
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
48.0
98.0
107.5
109.0
40.0
104.0
112.5
113.0
50
106.5
113
114
65.0
62.0
62.5
58.0
55.5
57.5
67
65
49.0
48.0
49.0
43.0
46.5
45.0
68
47
95
111
106
109.5
115.5
117.5
65
63
65.5
111
113
116
256
WITHAM HILL DATA
5/30/96
Site 3
6/14/96
6/21/96
275
129
202
6/28/96
Field Data
W-100
P-75-1
P-75-2
P-75-3
Benton County
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
-45.5
-63.5
-66.5
-72.5
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-50-1
-41
E-50-2
E-50-3
-25
-7
E-30-1
-74
-89
251
119
219
385
60
306
253
117
335
15.8
16.3
19.3
150
256
15.6
15.8
17.3
24.1
20.5
6/14/96
6/21/96
132
96
375
310
403
336
420
399
TC-50
TC-30
TC-10
AMBIENT
14.3
14.3
14.4
15.6
15.8
16.3
19.3
24.1
15.6
15.8
17.3
PPT in.
0.11
0
0.1
E-30-2
E-30-3
E-10-1
-31
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
198
160
68
14.3
14.3
14.4
15.6
DO-W100
1.4
D075-1
D075-2
D075-3
6.8
5.5
6.2
357
160
260
289
374
137
315
370
398
314
375
286
175
336
390
315
360
148
316
386
132
328
361
381
352
309
326
217
189
319
120
311
314
359
250
291
172
184
318
13.9
12.4
10.4
11.2
344
15.5
15.6
17.4
27.9
12.6
12.2
10.6
11.9
D035-1
D035-2
D035-3
D020-1
D020-2
D020-3
Corrected
Average
W-100
P-75
P-35
P-20
E-50
E-30
E-10
5/30/96
6/28/96
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
-45.5
-67.5
411
432
523
433
20.5
0.75
434
516
437
438
512
418
420
490
409
15.5
15.6
17.4
27.9
13.9
12.4
10.4
11.2
12.6
12.2
10.6
11.9
0
0.39
1.37
June
PPT cm
DO W100
DO 75
DO 35
DO 20
0.28
1.4
6.2
117
0.25
1.91
0.99
3.48
5.51
045
1.39
Oct
Nov
3.53
1.14
257
5/30/96
Benton County
Site 3
WITHAM HILL DATA
6/14/96
6/21/96
6/28/96
350
200
5
350
200
5
350
200
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
Saturation (gr.:
20 cm
35 cm
75 cm
Data Lines
(graphing)
1
350
200
5
Solution pH
pH 75
pH 35
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
71.5
111.5
117.5
117.5
5
350
200
5
350
200
350
200
350
200
350
200
350
200
350
200
5
5
5
5
5
5
258
WITHAM HILL DATA
Field Data
W-100
Site 3
Benton County
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
-2.0
P-75-1
-38.5
-48.0
-57.0
P-75-2
P-75-3
P-35-1
1/11/97
1/20/97
1/25/97
-6.5
-67.0
-1.0
-53.0
-64.0
-0.5
-56.0
-57.0
-77.0
-9.0
-49.5
-54.0
-72.5
-2.0
-52.5
-53.5
-70.0
-37.0
-42.0
-59.5
-9.5
-38.0
-45.0
-59.5
-2.5
-42.5
-48.5
-62.0
-1.0
-49.0
-52.0
-64.5
1.0
P-35-2
P-35-3
-7.0
-1.0
-8.5
-10.5
-5.0
-11.5
-5.5
-0.5
-6.5
-6.5
0.5
-5.5
-14.5
-8.5
-12.5
-7.5
-2.5
-7.0
-5.5
0.0
-1.5
-15.0
-9.0
-13.0
-11.0
-2.0
-6.5
-7.5
-2.5
-6.0
P-20-1
P-20-2
P-20-3
-3.5
-3.0
-7.0
-6.0
-7.0
-12.0
-1.5
-2.5
-6.0
-1.5
-2.0
-5.5
-8.0
-10.5
-12.5
-2.5
-2.5
-8.0
1.0
-1.0
-2.5
-8.5
-11.5
-12.0
-3.5
-3,5
-6.0
-2.0
-3.5
-6.0
5
-14
-33
-113
-27
-28
21
8
13
-1
-23
-1
15
-115
-321
9
-17
-100
32
-25
-48
-40
-9
-37
-111
8.9
8.4
7.8
-28
-10
-19
20
-20
-17
2
-3
9
7.3
6.2
3.9
7.2
-45
-17
-44
-45
-54
-63
-25
-30
-30
8.1
8.1
8.3
7.9
8.9
10.5
E-50-1
349
276
E-50-2
E-50-3
111
30
254
126
37
162
E-30-1
336
306
309
175
214
325
10.7
295
272
279
40
25
-13
10.1
8.6
7.0
5.4
11.9
9.1
-37
-49
8.8
8.6
8.3
6.2
DO-W100
7.5
3.9
1.4
1.7
3.4
D075-1
D075-2
D075-3
9.2
9.9
9.4
6.8
6.7
8.7
7.6
8.6
8.4
7.6
D035-1
D035-2
D035-3
6.1
2.4
0.9
9.0
6.7
1.3
1.6
D020-1
6.1
2.1
D020-2
D020-3
4.5
1.6
1.8
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
Corrected
Average
9
21
-10
-10
8.0
-32
-43
-48
-57
-123
-78
6.8
7.0
7.7
-45
-100
-28
-48
-126
-48
6.6
6.2
4.8
9.0
10.1
2.1
3.1
2.2
1.3
3.6
8.2
7.5
7.4
6.6
5.9
6.9
5.0
6.2
9.6
9.4
8.3
9.4
1.7
2.2
1.7
1.2
1.9
1.4
1.2
1.4
1.5
1.3
1.3
1.3
0.7
2.5
2.8
3.3
2.1
1.2
2.2
3.2
1.6
1.9
1.6
1.6
2.4
2.2
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
1/25/97
-46.2
-2.3
-0.8
-9.5
-47.5
-12.3
-10.7
-2.5
-51.0
-6.5
-4.3
-1.0
-55.2
-5.3
-3.8
147
126
114
47
123
120
82
151
133
115
6.8
7.0
6.6
6.2
8.0
7.7
4.8
9.0
10.1
2.1
0.52
2.25
0.8
17.27
1.32
5.72
2.03
3.1
2.2
7.7
1.4
2.2
1.3
6.5
1.3
1.7
3.6
5.8
1.2
1.8
291
9.8
10.0
138
154
272
9.1
6.4
W-100
P-75
P-35
P-20
11
37
139
8.8
8.5
8.9
0.7
1.3
1.1
1.6
1.5
1.8
-11
1.4
1.6
1.6
1.3
1.7
-136
-121
-141
-113
-84
-128
6.9
6.6
6.8
9.9
8.4
-2.0
-47.8
-5.5
-4.5
-6.5
-67.0
-9.0
-8.3
-1.0
-58.5
-4.2
-3.3
-0.5
-63.3
-3.8
-3.0
-9.0
-58.7
-11.8
-10.3
-2.0
-58.7
-5.7
-4.3
-14
-41
-91
-25
1.0
E-50
E-30
E-10
407
478
406
343
443
356
265
178
230
168
123
115
151
148
155
170
85
142
135
TC-50
TC-30
TC-10
AMBIENT
10.7
9.1
8.9
8.4
9.1
7.3
6.2
3.9
7.2
6.9
6.6
6.8
9.9
8.3
8.9
10.5
7.9
10.0
8.8
8.6
8.3
6.2
8.1
8.6
7.0
5.4
8.8
8.5
8.9
11.9
8.1
10.1
PPT in.
0.57
6.58
2.46
3.08
5.02
0.69
4.43
6.8
9.8
7.8
28
59
Dec
PPT cm
DO W100
DO 75
DO 35
DO 20
1.45
1.3
1.6
2.2
1.5
103
94
Jan
16.71
6.25
7.82
12.75
1.75
7.5
9.5
7.3
5.7
3.9
6.8
1.8
1.4
7.7
1.0
1.6
1.7
3.4
8.5
1.8
6.1
8.2
1.3
1.5
1.9
2.9
11.25
9.0
1.5
2.2
259
Benton County
Site 3
WITHAM HILL DATA
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
1/25/97
3
2
Saturation (gr
20 cm
35 cm
75 cm
Data Lines
(graphing)
3
2
3
2
3
2
3
2
3
2
3
2
3
2
2
3
2
1
1
1
1
1
1
1
1
1
350
200
350
200
5
350
200
350
200
5
5
350
200
5
3
350
200
5
5
350
200
350
200
350
200
350
200
350
200
5
5
5
5
5
Solution pH
pH 75
pH 35
pH 20
5.32
6.05
5.96
6.02
5.01
5.67
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
27
26.5
101
115
104
108
122
35
97.5
105
117.5
28
100.5
104.5
115
25
85
93
104.5
35.5
86
96
104.5
28.5
90.5
99.5
107
27
97
103
109.5
49
45
52
44
40.5
47
45
39.5
46
53
48.5
53
46
42.5
47.5
44
40
42
53.5
49
53.5
49.5
42
47
46
42.5
46.5
36.5
35
40
32
30.5
34
32
30
33.5
38.5
38.5
40.5
33
30.5
36
29.5
29
30.5
39
39.5
40
34
31.5
34
32.5
31.5
34
32.5
115
P-75-2
P-75-3
28
86.5
99
102
P-35-1
45.5
P-35-2
P-35-3
41
P-20-1
P-20-2
P-20-3
34
P-75-1
no
no
no
no
no
no
49
31
35
260
WITHAM HILL DATA
Benton County
Site 3
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
-2.5
-43.0
-49.0
-60.5
-9.5
-44.0
-50.0
-61.0
-13.0
-46.0
-52.0
-63.0
-11.5
-47.5
-53.5
-64.0
-1.5
-48.5
-53.5
-63.0
-2.5
-42.0
-48.0
-60.0
-3.5
-48.0
-50.0
-60.0
-10.5
-46.0
-50.0
-59.5
-13.5
-48.5
-51.0
-61.0
-23.0
-53.0
-58.0
-67.0
-25.0
-54.0
-60.0
-66.5
-8.0
-2.0
-5.5
-15.0
-9.0
-13.0
-19.0
-12.5
-16.5
-19.0
-12.0
-16.0
-ro
-1.5
-5.5
-8.0
-2.5
-6.0
-11.5
-2.5
-7.5
-15.0
-10.0
-13.0
-20.5
-14.5
-18.0
-27.0
-22.0
-26.0
-29.5
-25.0
-28.0
-4.0
-4.0
-5.5
-9.5
-13.0
-11.5
-13.5
-16.0
-14.5
-13.5
-15.0
-14.5
-4.0
-4.0
-5.5
-2.5
-4.0
-7.0
-6.5
-5.0
-7.0
-10.5
-13.0
-11.5
-14.5
-17.0
-15.0
-104
-66
-17
-7
-52
-15
-7
-50
-51
-4
-18
-23
-17
-24
-4
-10
-40
0
-3
3
-43
-3
-74
-8
-44
-12
-7
3
6
6
-47
-29
-30
-53
-51
-54
-13
-50
-84
-38
-16
-33
-231
-216
-83
8.4
8.2
9.4
-96
-52
-95
-363
-234
-68
10.0
9.7
13.1
-75
-29
-44
-355
-254
-65
9.6
9.9
8.7
15.6
9.5
-75
-42
-82
-320
-252
-85
9.8
9.5
9.9
16.8
-78
-33
-79
-365
-187
-100
10.0
9.8
10.7
14.2
Field Data
W-100
P-75-1
P-75-2
P-75-3
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
E-30-1
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
6
-28
-22
-30
-40
-77
-109
-60
7.9
8.2
8.3
10.0
9.1
15.0
-52
-36
-43
-79
-286
-52
8.0
7.5
5.6
8.2
-191
-40
6.3
6.3
6.3
-38
-36
-76
-244
-49
7.1
7.1
8.1
1
-42
-54
8
7.3
7.3
8.0
-148
-200
-107
7.9
7.9
8.8
12.5
-221
-83
7.7
9.1
DO-W100
1.6
2.3
2.4
2.2
4.1
2.0
2.4
0.8
1.3
1.8
1.4
0075-1
0075-2
0075-3
6.3
7.0
5.7
6.6
7.3
6.3
6.3
7.3
6.2
7.7
7.6
6.2
5.3
7.8
6.9
6.7
7.8
8.3
6.1
7.2
7.4
6.3
7.7
7.3
4.1
8.1
5.9
7.6
8.5
D035-1
D035-2
D035-3
1.1
0.9
1.6
1.6
1.6
1.6
1.3
1.6
1.0
1.7
1.5
0.9
1.5
1.1
1.3
1.4
1.2
1.6
2.2
1.3
1.4
1.6
1.2
1.6
1.7
0020-1
D020-2
D020-3
1.4
1.3
1.6
1.7
1.3
2.2
1.5
1.9
2.2
1.5
1.8
2.0
1.6
1.7
1.3
1.7
1.7
1.2
1.3
1.4
2.1
2.1
1.9
1.8
1.6
2.0
1.6
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
-2.5
-50.8
-5.2
-4.5
-9.5
-51.7
-12.3
-11.3
-13.0
-53.7
-16.0
-14.7
-11.5
-55.0
-15.7
-14.3
-1.5
-55.0
-4.7
-4.5
-2.5
-50.0
-5.5
-4.5
-3.5
-52.7
-7.2
-6.2
114
130
86
126
126
73
132
119
45
139
117
29
132
122
38
143
132
TC-50
TC-30
TC-10
AMBIENT
7.9
8.2
8.3
10.0
6.3
6.3
6.3
7.1
7.1
8.1
9.1
15.0
8.0
7.5
5.6
8.2
7.7
7.3
7.3
8.0
7.9
7.9
8.8
12.5
PPT in.
3.31
0.24
Feb
0.41
0.75
PPT cm
8.41
0.61
1.04
1.91
0.35
Mar
0.89
1.6
6.3
1.3
1.4
2.3
6.7
1.4
1.7
2.4
6.6
1.3
1.9
2.2
7.2
1.4
1.8
4.1
7.1
1.5
1.5
Corrected
Average
W-100
P-75
P-35
P-20
E-50
E-30
E-10
DO W100
DO 75
DO 35
DO 20
6.1
7.8
7.3
8.7
1.8
9.7
2.2
1.8
3.3
2.5
3/30/97
4/05/97
4/12/97
-10.5
-51.8
-12.7
-11.7
-13.5
-53.5
-17.7
-15.5
-23.0
-59.3
-25.0
-25.0
-60.2
-27.5
144
132
-9
142
112
-57
142
80
-54
131
-51
140
98
-50
8.4
8.2
9.4
9.6
9.9
8.7
10.0
9.7
13.1
15.6
9.5
9.8
9.5
9.9
16.8
10.0
9.8
10.7
14.2
2.45
2.11
1.22
0.23
0.35
6.22
5.36
3.10
0.58
0.45
April
1.14
2.0
6.7
1.2
1.5
2.4
7.6
1.7
1.8
0.8
6.9
1.4
1.8
1.3
1.8
7.0
4.6
1.4
1.1
1.5
16
9.1
7.1
1.5
1.7
95
0.89
7.3
2.5
261
WITHAM HILL DATA
2/01/97
2/08/97
Site 3
Benton County
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
Saturation (gri
20 cm
35 cm
75 cm
Data Lines
(graphing)
3
3
3
2
3
2
3
2
3
2
3
2
2
2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
350
200
5
350
200
5
350
200
5
350
200
5
350
200
350
200
5
350
200
350
200
350
200
5
5
5
350
200
5
350
200
5
5
Solution pH
pH 75
pH 35
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
yes
yes
yes
28.5
35.5
92
37.5
95.5
104.5
109
27.5
96.5
104.5
108
28.5
90
99
105
29.5
96
106
39
94
103
108
46.5
42
46
53.5
49
53.5
57.5
52.5
57
57.5
52
56.5
45.5
41.5
46
46.5
42.5
46.5
50
42.5
48
34.5
32
33.5
40
44
44
42.5
44
43
42.5
34.5
32
33.5
33
32
35
37
33
35
P-75-1
91
P-75-2
P-75-3
100
105.5
101
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
yes
yes
no
41
39.5
36.5
94
39.5
96.5
101
101
101
105
104.5
102
106
109
112
53.5
50
53.5
59
54.5
58.5
65.5
62
66.5
41
41
39.5
45
45
43
49
51
102
111
111.5
68
65
68.5
262
Benton County
Site 3
WITHAM HILL DATA
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
-17.0
-48.5
-54.5
-63.0
-12.5
-50.5
-56.0
-63.0
-42.0
-61.5
-67.5
-70.5
-76.5
-72.0
P-75-2
P-75-3
-17.5
-57.0
-60.0
-69.0
P-35-1
P-35-2
P-35-3
-24.5
-19.0
-22.5
-22.0
-16.5
-16.5
-18.0
-13.0
-15.0
-16.0
-20.0
-16.0
-11.5
-16.5
-15.0
-52
-39
2
-20
48
188
82
6
231
123
-63
-68
350
108
270
16.3
17.2
20.9
18.5
349
209
230
243
172
229
234
15.8
15.7
16.3
15.8
17.1
12.2
13.0
14.4
-112
-70
-125
253
132
-212
14.5
15.4
18.2
29.3
5/24/97
6/01/97
6/07197
Field Data
W-100
P-75-1
P-20-1
P-20-2
P-20-3
E-50-1
E-50-2
E-50-3
-40
-16
-2
-44
-16
-2
-36
E-30-1
-69
-74
-63
-307
166
-122
11.4
11.9
13.3
16.4
-88
-74
-92
-243
-50
-22
-47
-103
46
37
DO-W100
1.7
1.4
1.2
2.3
2.0
D075-1
5.3
6.5
7.2
5.0
7.4
3.8
5.4
8.1
8.0
5.2
7.0
7.6
2.0
3.0
1.5
2.7
1.5
1.2
2.0
1.5
1.3
3.3
1.0
2.0
2.0
2.4
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
-17.5
-62.0
-22.0
-17.0
-55.3
-18.3
-17.3
-12,5
-56.5
-15.3
-14.3
-42.0
-66.5
-76.5
-72.0
137
92
80
136
76
90
152
127
59
225
168
158
TC-50
TC-30
TC-10
AMBIENT
11.4
11.9
13.3
16.4
12.2
12.6
15.3
22.6
12.1
PPT in.
0.68
1.88
PPT cm
1.73
DO W100
DO 75
DO 35
DO 20
1.7
6.3
2.4
E-30-2
E-30-3
E-10-1
E-10-2
E-10-3
TC-50
TC-30
TC-10
AMBIENT
D075-2
D075-3
D035-1
D035-2
D035-3
2.1
D020-1
D020-2
D020-3
Corrected
Average
W-100
P-75
P-35
P-20
E-50
E-30
E-10
166
-156
12.2
12.6
15.3
22.6
21
1
12.1
6.1
-20.5
112
68
214
143
286
245
176
286
17.3
18.1
18.5
7.2
5/24/97
6/01/97
6/07/97
-20.5
410
323
424
382
288
382
403
14.5
15.4
18.2
29.3
16.3
17.2
20.9
18.5
15.8
15.7
16.3
15.8
17.1
0.11
0
0.37
1.58
June
1.09
4.78
0.68
May
1.73
0.94
4.01
2.77
1.4
6.8
1.9
2.2
1.2
6.0
1.6
1.8
2.3
6.6
121
161
12.2
13.0
14.4
0.28
2.0
5.4
17.3
18.1
18.5
7.2
263
WITHAM HILL DATA
Site 3
4/18/97
4/26/97
5/03/97
2
3
2
2
1
1
1
350
200
5
350
200
5
5/10/97
5/16/97
Benton County
5/24/97
6101/97
6107(97
350
200
5
350
200
350
200
5
Saturation (gr:
20 cm
35 cm
75 cm
Data Lines
(graphing)
350
200
5
3
1
350
200
5
1
350
200
5
5
Solution pH
pH 75
pH 35
pH 20
5.56
5.63
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100
yes
yes
yes
43.5
38.5
98.5
114
43
96.5
105.5
108
63
59
63
60.5
56.5
57
56.5
53
55.5
46.5
48
44
42
44.5
43
P-75-1
105
P-75-2
P-75-3
111
P-35-1
P-35-2
P-35-3
P-20-1
P-20-2
P-20-3
no
yes
no
107
108
68
109.5
118.5
115.5
102.5
120
46.5
264
WITHAM HILL DATA
Field Data
Site 4
Benton County
10\ 10\95 10/17/95 10/24/95 10 \ 31 \95 11 \07\95
95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
W-100
-27.4
-44.0
P-100-1
P-100-2
P-100-3
P-50-1
P-50-2
P-50-3
-22.2
-19.4
P-25-1
-23.3
-23.3
-20.3
-33.1
P-25-2
P-25-3
-40.9
-37.8
-35.3
E-100-1
E-100-2
E-100-3
192
206
194
211
199
131
195
166
123
201
185
153
452
442
439
131
121
128
106
154
E-50-1
246
153
271
180
E-25-1
232
264
340
416
522
424
474
503
607
-81
261
185
187
252
112
245
297
333
172
E-50-2
E-50-3
-46
-10
42
-297
172
E-25-2
E-25-3
TC-100
TC-50
TC-25
AMBIENT
241
129
164
210
250
254
266
341
78
104
-96
96
25
131
31
13.2
12.6
11.4
11.8
D0-W100
1.9
-5.7
-2.8
-1.9
-95.9
-64.2
-36.6
-31.9
-18.5
-4.7
-78.9
-31.0
-19.0
-2.6
-17.7
-5.2
-1.7
-4.3
-8.6
-0.9
-1.7
-3.4
-5.2
-3.4
-3.4
-3.4
-6.0
-3.7
-2.6
-5.2
-0.7
-2.6
-4.3
-0.9
-3.4
-5.2
-1.3
55
49
78
-5
32
-24
-43
-13
-253
-235
-207
-383
16
-12
-393
-415
-318
-193
-372
7
12.1
11.1
11.4
13.7
9.4
1.8
5.8
10.0
7.0
7.5
10.6
10.3
6.8
6.2
8.0
6.5
4.8
2.6
5.4
10.6
2.5
2.9
2.3
3.4
4.6
3.0
4.4
3.1
-373
-3
-46
12.9
34
-45
12.7
00100-2
00100-3
9.3
7.7
Corrected
Average
7.0
4.9
3.5
10 \ 10 \ 95
W-100
P-100
P-50
P-25
E-100
447
417
453
E-50
E-25
PPT in.
0.06
430
370
466
411
367
382
429
388
694
461
702
2.26
0.55
641
0.82
Oct
DO 100
DO 100
DO 50
DO 25
-114
11.5
9.8
9.1
8.8
7.6
2.8
3.4
2.3
2.1
3.1
0.7
-5.7
-95.9
-8.5
-4.4
310
45
34
-2.8
-50.4
-4.9
-2.8
5
-1.9
-25.2
-2.0
-2.6
223
-39
40
189
13.2
12.6
11.4
11.8
12.9
12.7
12.1
11.1
11.5
9.8
11.4
13.7
9.4
1.8
11.8
10.2
9.4
10.9
0.26
2.96
3.38
3.74
2.71
-27.4
-44.0
-24.9
-22.3
-38.0
371
220
183
385
2.51
182
143
Nov
0.15
-261
10/17/95 10/24/95 1O\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
TC-100
TC-50
TC-25
AMBIENT
PPT cm
3.2
3.7
0025-1
0025-2
D025-3
-112
-413
-166
-97
273
-95
-133
11.8
10.2
9.4
10.9
-151
D0100-1
0050-1
0050-2
D050-3
-281
5.74
1.40
2.08
261
-4.7
-43.0
-4.0
-3.3
34
-122
-75
9.1
8.8
Dec
1.78
6.38
0.66
7.52
8.59
9.50
6.88
1.9
5.8
10.0
10.5
8.5
3.5
6.2
4.0
7.0
6.5
2.7
2.7
7.5
6.4
4.4
2.9
5.1
265
WITHAM HILL DATA
Site 4
Benton County
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95
Saturation (graphing)
25 cm
50 cm
100 cm
Data Lines
(graphing)
3
2
350
200
5
350
200
350
200
5
5
350
200
5
2
350
200
350
200
350
200
5
5
77.0
3
3
3
3
2
2
2
2
1
1
1
1
350
200
5
350
200
5
350
200
5
5
350
200
5
59.4
100.0
103.0
104.0
4.8
41.5
73.5
79.0
94.5
101.0
24.5
80.0
94.0
55.0
37.5
52.0
56.0
53.0
48.0
57.0
56.0
54.0
52.0
54.0
54.0
25.0
22.0
24.7
26.0
23.0
28.2
26.0
24.0
28.0
25.0
23.0
27.5
Solution pH
pH 100
pH 50
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100 C
P-100-1 C
P-100-2C
P-100-3C
P-50-1C
P-50-2C
P-50-3C
32.2
35.5
19.6
P-25-1C
P-25-2C
P-25-3C
2.0
2.0
5.5
10.5
14.2
17.0
266
WITHAM HILL DATA
Site 4
Benton County
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
-10.4
-66.8
-16.4
-6.0
-5.0
-64.5
-17.0
-9.0
-4.0
-56.0
-9.0
-5.0
-3.0
-62.0
-9.5
-4.5
-3.5
-62.5
-11.0
-7.0
-5.5
-62.0
-11.5
-8.0
-3.5
-28.5
-7.0
-4.5
-2.5
-35.0
-5.5
-3.0
-1.0
-61.0
-11.0
-6.5
-4.0
-60.0
-12.5
-10.0
-4.0
-56.0
-8.0
-5.0
-5.2
-0.9
-2.2
-3.5
-1.0
-3.5
-3.5
-0.5
-2.0
-1.5
P-50-2
P-50-3
-2.5
-3.0
0.0
-3.0
-3.0
-0.5
-5.0
-2.5
0.5
0.5
-4.0
-0.5
-2.5
-2.5
0.5
-5.0
-4.5
-2.0
-4.5
-3.5
-1.5
-3.5
P-25-1
P-25-2
P-25-3
-3.4
-4.3
-0.9
-5.5
-4.0
-3.5
-5.0
-4.0
-8.5
-3.5
-1.5
-1.5
-4.5
-3.0
-2.5
-5.0
-3.5
-2.5
-3.5
-2.5
-1.5
-4.5
-3.5
-2.5
-3.5
-1.5
-2.0
-6.0
-4.5
-4.5
-5.0
-3.5
-3.5
E-100-1
E-100-2
E-100-3
-112
-78
-298
-93
-471
-107
-225
-140
-107
-225
-140
-68
-226
-83
-155
-358
-120
-83
-287
-71
-82
-319
-66
-77
-224
-125
-76
-242
-133
E-50-1
-421
-133
-182
-353
-423
-386
-148
-244
-220
-436
-124
-99
-366
25
-191
-81
9.3
8.6
8.5
13.4
9.7
7.9
6.4
5.8
-382
-20
-136
9.5
8.8
-385
9
-437
-333
-136
-372
-196
-114
8.6
8.4
-428
-143
-6
8.1
13.1
8.1
2.6
-437
-333
-136
-372
-196
-114
8.9
7.4
7.8
10.5
-436
-140
-384
-318
-20
10.4
9.3
9.0
5.4
-424
-237
-306
-287
-142
-24
10.2
9.0
7.7
7.6
-431
E-50-2
E-50-3
E-25-1
E-25-2
E-25-3
TC-100
TC-50
TC-25
AMBIENT
Field Data
W-100
P-100-1
P-100-2
P-100-3
P-50-1
-267
-82
-429
-150
-232
-389
29
38
27
11.0
8.2
5.2
3.7
31
9.9
-431
-385
-351
1.0
-131
6.6
4.1
-101
-184
12
-361
-381
12
4.9
-85
9.2
7.7
6.4
15.4
-188
9.0
9.0
9.7
17.2
4.1
2.6
6.1
4.7
3.0
4.3
4.5
1.9
1.8
1.7
2.4
3.2
DO-W100
5.9
3.3
3.7
9.2
7.7
6.3
3.5
2.0
00100-1
D0100-2
D0100-3
6.0
9.6
11.0
8.5
6.5
9.1
8.9
9.3
7.6
8.7
5.8
5.4
8.7
7.1
8.9
8.9
6.9
5.6
6.9
8.1
4.1
0050-1
3.2
5.9
2.0
3.3
9.1
8.4
2.3
2.7
7.2
1.7
2.3
1.2
2.3
5.1
5.1
7.9
2.1
2.9
7.6
4.3
3.6
2.5
6.0
2.3
1.5
2.5
1.2
1.9
3.3
2.1
5.1
2.3
2.4
2.0
2.7
2.0
1.9
3.2
3.4
0050-2
0050-3
0025-1
8.8
10.3
0025-2
3.0
2.8
D025-3
2.1
2.9
3.3
2.6
12/26/95
1/02/96
-10.4
-29.7
-2.7
-2.9
96
-59
-5.0
-30.2
-2.7
-4.3
Corrected
Average
W-100
P-100
P-50
P-25
E-100
E-50
E-25
TC-100
TC-50
TC-25
AMBIENT
11.0
PPT in.
0.08
3.3
7.0
DO 100
DO 100
DO 50
DO 25
5.6
1.8
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
-4.0
-23.3
-2.0
-5.8
34
-202
-3.5
-26.8
-2.0
-3.3
38
-132
-5.5
-27.2
-2.8
-3.7
82
-33
64
-3.5
-13.3
-0.5
-2.5
92
-115
-53
-2.5
-14.5
-2.3
-3.5
92
-115
-53
-1.0
-26.2
-2.3
-2.3
-4.0
-27.5
-3.7
-5.0
107
-32
22
-4.0
-23.0
-2.8
-4.0
99
-124
-66
-3.0
-25.3
-1.0
-2.2
94
-136
23
9.9
8.6
8.5
13.4
10.4
9.3
9.0
5.4
10.2
9.0
7.7
7.6
9.7
7.9
6.4
5.8
9.3
6.6
8.6
9.5
8.8
2.6
8.9
7.4
7.8
10.5
8.1
13.1
9.2
7.7
6.4
15.4
9.0
9.0
9.7
17.2
1.5
1.75
3.26
4.09
1.27
6.5
0.04
0.55
March
11.38
1.40
1.73
18
4.1
8.4
Feb
0.20
3.81
4.45
8.28
10.39
3.23
16.51
0.10
5.9
3.3
8.7
4.2
3.7
7.7
5.8
3.5
9.2
8.6
7.7
6.6
6.3
7.6
7.1
4.1
2.1
4.1
3.5
8.6
1.7
1.7
2.0
5.5
2.7
8.1
6.5
2.6
3.9
4.0
2.9
2.9
Jan
PPT cm
3.1
5.0
2.5
1.9
-84
65
8.2
5.2
3.7
7.6
4.6
4.4
5.1
100
78
6.5
2.9
5.6
2.7
2.1
118
-82
-5
8.1
4.9
4.48
3.9
2.6
4.4
1.9
2.7
2.1
2.1
4.1
-11
4.39
6.1
4.7
3.7
3.9
267
WITHAM HILL DATA
Site 4
12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
2/17/96
2/23/96
3/01/96
3/08/96
3
2
3
2
3
3
2
3
3
2
3
2
3
2
2
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
1
350
200
350
200
350
200
350
200
350
200
350
200
5
5
350
200
5
5
5
5
5
350
200
5
350
200
5
Saturation (gr
25 cm
50 cm
100 cm
Data Lines
(graphing)
Benton County
350
200
5
350
200
5
Solution pH
pH 100
pH 50
pH 20
6.95
5.7
5.52
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100 C
P-100-1C
P-100-2C
P-100-3C
95.0
38.5
97.0
109.0
30.0
89.5
42.0
34.0
29.0
81.0
34.0
30.0
28.0
87.0
34.5
29.5
28.5
87.5
36.0
32.0
30.5
87.0
36.5
33.0
28.5
53.5
32
29.5
27.5
60.0
30.5
28.0
26.0
86.0
36.0
31.5
29.0
85.0
37.5
35.0
29.0
81.0
33.0
30.0
P-50-1C
P-50-2C
P-50-3C
52.0
57.0
55.5
29.0
27.5
27.0
29.0
27.0
25.5
27.0
25.5
26.0
28.5
26.5
26.5
28.5
27.0
28.5
28
26
23
29.5
27.0
26.0
28.0
26.0
28.5
30.0
28.5
28.0
29.0
28.0
27.0
P-25-1 C
25.0
24.0
28.0
29.5
30.5
28.0
29.0
30.5
33.0
27.5
28.0
26.0
28.5
29.5
27.0
29.0
30.0
27.0
27.5
29
26
28.5
30.0
27.0
27.5
28.0
26.5
30.0
31.0
29.0
29.0
30.0
28.0
P-25-2C
P-25-3C
268
WITHAM HILL DATA
Site 4
Benton County
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
-5.0
-55.5
-9.0
-6.0
-4.0
-53.0
-7.5
-5.0
-6.0
-57.5
-11.5
-8.5
-7.0
-41.0
-11.5
-8.0
-17.0
-59.0
-17.0
-14.0
-2.0
-61.0
-9.0
-6.5
-3.5
-57,0
-8.5
-6.0
-17.0
-50.0
-13.0
-12.0
-35.0
-73.0
-30.0
-26.0
-8.0
-69.0
-19.0
-17.0
-6.5
-54.0
-9.0
-6.0
P-50-2
P-50-3
-5.0
-2.0
-4.5
-4.0
-1.0
-5.0
-5.5
-3.0
-6.0
-6.0
-4.0
-3.5
-15.5
-12.5
-14.5
-3.0
-0.5
-3.5
-3.5
-1.0
-3.0
-13.5
-9.5
-8.5
-32.5
-29.5
-27.0
-5.5
-3.5
-12.5
-5.0
-2.5
-3.5
P-25-1
P-25-2
P-25-3
-6.0
-4.5
-4.0
-5.5
-4.5
-4.0
-8.0
-5.5
-5.5
-8.0
-6.5
-6.5
-18.5
-17.0
-15.0
-4.5
-3.5
-3.5
-5.0
-3.5
-3.5
-16.0
-13.5
-15.5
-8.0
-4.5
-7.0
-7.5
-5.0
-5.5
E-100-1
E-100-2
E-100-3
-389
-89
-244
-44
-82
-387
-102
-362
-17
-67
-159
-312
-33
-123
-194
-137
-56
-253
-32
-171
8
-380
-86
-164
-117
-251
-31
-131
E-50-1
-432
-428
-119
-402
-389
-407
-353
-358
-359
-392
-138
-316
-359
-380
-131
-410
-109
-385
-364
26
-95
10.4
10.0
9.3
12.2
-429
E-50-2
E-50-3
13.8
14.8
19.7
-370
-122
-410
-373
-149
-172
13.2
13.7
13.2
21.2
Field Data
W-100
P-100-1
P-100-2
P-100-3
P-50-1
6
-157
E-25-1
-345
-389
E-25-2
E-25-3
TC-100
TC-50
TC-25
AMBIENT
6
-171
9.8
10.1
10.4
15.3
-434
-132
-391
-389
14
-122
10.4
10.5
9.8
13.7
6
-241
-78
10.7
11.0
10.9
18.5
-250
11.3
12.4
12.9
9.9
-408
-126
-347
-312
-18
-87
12.0
12.7
12.2
11.3
-251
-36
12.1
-389
-397
-164
-110
12.6
13.3
12.2
16.0
12.6
17.0
-408
-93
-286
-387
-180
-105
12.5
12.6
12.0
18.8
-141
-21
-73
11.9
-121
-404
-89
-149
-368
13.0
-169
DO-W100
1.5
1.1
1.1
1.0
1.0
0.9
1.3
1.3
1.3
1.3
D0100-1
D0100-2
D0100-3
4.5
3.4
2.9
4.6
4.3
4.6
4.5
3.6
3.2
4.0
2.3
1.7
2.4
10.5
11.3
6.4
6.0
6.5
4.5
3.9
4.6
2.6
4.0
3.9
3.0
2.6
1.1
2.0
1.5
4.6
1.0
1.0
3.3
0.9
1.4
0.8
1.8
2.1
3.4
2.1
1.3
1.0
2.0
1.3
3.1
3.1
1.7
2.0
2.3
2.5
1.4
1.8
3.0
1.4
2.0
2.8
1.4
1.2
1.6
1.2
4.8
5.6
2.8
D050-1
D050-2
D050-3
D025-1
D025-2
D025-3
Corrected
Average
W-100
P-100
P-50
P-25
E-100
E-50
E-25
TC-100
TC-50
TC-25
AMBIENT
PPT in.
1.8
1.2
1.4
1.3
4.4
1.8
1.3
2.7
2.4
2.1
1.5
1.1
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
-5.0
-23.5
-3.8
-4.8
69
-116
-10
-4.0
-21.8
-3.3
-4.7
-7.0
-20.2
-4.5
-7.0
-17.0
-30.0
-14.2
-16.8
-2.0
-25.5
-2.3
-3.8
-3.5
-23.8
-2.5
-4.0
-17.0
-25.0
-10.5
-15.0
9
-6.0
-25.8
-4.8
-6.3
93
-115
30
9.8
10.4
15.3
10.4
10.5
9.8
13.7
10.4
10.0
9.3
12.2
0.43
0.2
0.7
10.1
2.7
124
-132
DO 100
DO 100
DO 50
DO 25
1.09
0.51
1.5
2.9
1.3
2.2
1.78
2.0
1.8
2.3
5/09/96
5/16/96
5/24/96
-35.0
-43.0
-29.7
-8.0
-35.0
-7.2
-6.5
39
136
101
115
133
21
-186
-109
-107
35
-95
23
-133
-49
-76
-50
-115
-28
10.7
11.0
10.9
18.5
11.3
12.4
12.9
9.9
12.0
12.7
12.2
11.3
11.9
12.6
13.3
12.6
17.0
12.5
12.6
12.0
18.8
13.0
13.8
14.8
19.7
13.2
13.7
13.2
21.2
0.98
0.78
0.72
2.9
0.06
0.17
1.63
2.04
0.15
0.43
4.14
5.18
1.3
1.3
5.7
2.8
1.3
1.3
3.2
1.7
2.0
89
-130
81
12.1
12.2
16.0
May
2.49
1.98
1.83
7.37
1.1
1.1
3.6
4.5
2.7
1.0
3.8
1.8
1.0
2.7
2.1
2.1
2.1
0.9
1.8
1.9
1.3
2.3
2.0
3.6
3.5
2.2
-6.5
-23.0
-3.7
-6.0
92
-114
-57
April
PPT cm
4.5
1.8
9.4
1.9
4.4
3.7
2.3
3.1
269
Benton County
Site 4
WITHAM HILL DATA
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
3
2
3
3
2
3
2
3
2
3
2
3
2
3
2
2
2
1
1
1
1
1
1
1
1
1
5/09/96
5/16/96
5/24/96
3
2
3
2
1
1
Saturation (gr
25 cm
50 cm
100 cm
Data Lines
(graphing)
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
350
200
5
5
32
66
36.5
33
42
84
42
39
27
86
34
31.5
28.5
82
33.5
42
60
98
55
31
75
38
37
31.5
30.5
27
41
28.5
27
27
29
27.5
26.5
39
36
32
32
33
42.5
43.5
39.5
28.5
30
29
30
28
40
40
40
350
200
5
350
200
33
94
44
42
31.5
79
34
31
30.5
29
27
5
Solution pH
pH 100
pH 50
pH 20
7.58
6.39
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100 C
P-100-1C
P-100-2C
P-100-3C
30.0
80.5
34.0
31.0
29.0
78.0
32.5
30.0
82.5
36.5
33.5
P-50-1C
P-50-2C
P-50-3C
30.5
28.5
28.0
29.5
27.5
28.5
29.5
29.5
P-25-1C
P-25-2C
P-25-3C
30.0
31.0
28.5
29.5
31.0
28.5
32
32
30
31
31
31
39
38
28
51
58
56
50.5
30
36
32
31
31.5
31
31.5
31.5
30
270
WITHAM HILL DATA
Field Data
W-100
P-100-1
P-100-2
P-100-3
P-50-1
6/14/96
6/21/96
-20.0
-63.5
-15.5
-13.0
-81.0
-70.0
-83.0
-76.0
-96.0
63
-52
-201
48
124
138
-205
-29
74
-68
76
-48
64
-87
138
18
119
79
70
248
-371
-155
152
9
156
23
239
123
139
115
269
-18.0
-14.5
-13.5
P-25-1
P-25-2
P-25-3
-20.5
-16.5
-18.0
E-100-1
E-100-2
E-100-3
-324
-86
-378
E-50-1
-327
-82
-378
-353
-250
-75
13.4
14.2
14.2
18.6
E-25-1
E-25-2
E-25-3
TC-100
TC-50
TC-25
AMBIENT
14.1
15.2
15.5
20.4
DO-W100
1.3
1.6
4.6
4.3
5.2
D0100-1
5.5
D0100-2
D0100-3
5.1
D050-1
D050-2
D050-3
2.3
1.2
4.7
D025-1
D025-2
D025-3
2.7
3.6
2.0
Corrected
Average
W-100
P-100
P-50
P-25
E-100
E-50
E-25
TC-100
TC-50
TC-25
AMBIENT
PPT in.
Benton County
5/30/96
P-50-2
P-50-3
E-50-2
E-50-3
Site 4
4.5
224
21.3
6/14/96
6/21/96
-20.0
-30.7
-15.3
-18.3
-13
-76
-52
-81.0
-76.3
-96.0
299
225
104
104
259
249
13.4
14.2
14.2
18.6
14.1
14.3
14.9
15.0
21.3
0.11
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
14.3
14.9
15.0
5/30/96
15.2
15.5
20.4
6/28/96
0.1
6/28196
269
115
238
14.6
14.7
14.9
20.0
68
249
173
75
270
154
275
14.4
13.7
110
177
97
273
155
278
13.0
12.3
11.9
11.6
12.1
11.9
300
343
382
291
14.6
14.7
14.9
20.0
14.4
13.7
DO 100
DO 100
DO 50
DO 25
12.1
11.9
0.39
1.37
2.17
0.25
1.6
4.7
1.91
0.99
3.48
0.45
1.39
Nov
Oct
0.28
1.3
5.0
2.7
2.8
280
315
410
352
407
June
PPT cm
12
13
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
267
315
349
0.75
151
65
-33
92
5.51
3.53
1.14
271
WITHAM HILL DATA
5/30/96
6/14/96
Site 4
6/21/96
6/28/96
Saturation (gr
25 cm
50 cm
100 cm
Data Lines
(graphing)
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96
3
2
1
1
350
200
5
350
200
350
200
350
200
5
5
5
45
88.5
40.5
38
106
95
108
121
Solution pH
pH 100
pH 50
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100 C
P-100-1C
P-100-2C
P-100-3C
Benton County
P-50-1C
P-50-2C
P-50-3C
43.5
P-25-1C
P-25-2C
P-25-3C
44.5
43
42.5
41
37
101
350
200
5
350
200
5
350
200
5
350
200
350
200
350
200
5
5
5
350
200
5
272
WITHAM HILL DATA
Field Data
W-100
-38.0
-6.0
-34.0
-29.5
-32.0
P-25-1
P-25-2
P-25-3
E-100-2
E-100-3
E-50-1
E-50-2
E-50-3
E-25-1
E-25-2
E-25-3
TC-100
TC-50
TC-25
AMBIENT
DO-W100
69
43
-24
36
188
146
275
157
284
11.5
10.7
10.1
10.0
9.0
9.5
9.9
10.0
P-100
P-50
P-25
E-100
E-50
E-25
-4.5
-55.0
-17.0
-14.5
-3.5
-28.5
-7.0
-4.5
-5.5
-26.5
-5.0
-4.0
-32.5
-6.5
-5.0
-3.5
-49.0
-6.5
-8.5
-4.0
-1.5
-2.0
-4.5
-1.5
-2.5
-3.5
-0.5
-1.5
-3.5
-0.5
-1.5
-4.5
-1.5
-2.5
-3.5
0.5
-4.0
-2.5
0.5
0.5
-4.0
-1.0
-2.0
-3.5
-1.5
-2.0
-2.5
0.0
-0.5
-5.5
-4.0
-4.0
-6.0
-4.0
-5.0
-3.0
-2.5
-5.0
-3.0
-2.5
-6.5
-4.0
-3.5
-5.0
-3.0
-2.5
-3.5
-2.5
-1.5
-5.5
-3.5
-3.0
-4.5
-2.5
-5.0
-3.5
-2.0
-1.5
40
9
-160
-63
-82
-60
19
12
-34
-25
7
-53
41
3
28
6
52
54
14
31
1
-3
-42
-52
-24
-10
7
2
-74
-35
-45
-16
-87
10.3
-13
-12
-90
-105
-115
-77
-29
-82
9.0
9
-7
-53
-40
2
-50
8.9
7.4
7.8
10.5
-50
-19
-235
-17
4.0
55
43
171
118
156
113
207
12.0
10.0
8.0
5.4
108
48
-56
-86
-90
11.0
9.3
8.3
12.0
6.1
4
11
-29
11
-2
10.9
9.0
7.3
18
24
47
2
13
27
-6
-1
-127
-12
-94
-42
-16
-144
8.3
6.7
6.6
-106
-43
-158
10.4
2.5
-79
-32
-145
8.4
6.6
8.3
6.9
-14
9.8
7.5
4.6
7.3
5.4
5.7
3.2
2.9
3.5
4.4
4.5
4.5
10.4
7.7
6.5
8.7
9.2
8.7
8.9
7.3
7.2
7.4
8.9
8.9
6.3
6.6
8.1
7.6
6.3
6.5
3.1
4.4
3.0
2.8
6.4
4.0
5.5
2.9
0.9
1.8
0.8
1.3
1.6
1.0
1.5
1.0
1.6
1.6
1.6
1.7
2.3
1.2
1.4
1.2
1.2
3.1
1.2
2.0
1.4
1.7
2.3
1.4
1.2
1.6
1.8
1.5
2.3
1.7
1.5
2.5
9.1
8.1
7.1
5.9
10.0
-89
9.2
8.0
7.4
7.9
5.1
1.3
1.3
0.9
1.6
1.5
1.1
1.2
1.2
1.9
1.2
1.1
1.5
1.2
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
1/25/97
4.5
4.0
-3.5
-21.3
-1.0
-2.3
217
109
107
238
84
89
5.0
3.4
-38.0
-31.8
-6.0
-2.5
-6.0
-55.0
-2.8
4.5
170
145
9.0
7.1
5.9
10.0
8.9
7.4
7.8
10.5
9.2
8.0
7.4
7.9
8.3
6.7
6.6
10.4
8.4
6.6
6.9
9.8
7.5
4.6
7.3
5.02
0.69
4.43
6.8
0.52
2.25
0.8
17.27
1.32
5.72
2.03
3.5
8.6
1.7
1.7
4.4
4.5
5.3
4.5
3.4
1.0
1.4
1.1
168
125
10.3
9.1
TC-100
TC-50
TC-25
AMBIENT
11.5
10.7
11.0
10.9
9.3
10.0
12.0
10.0
8.0
5.4
9.0
7.3
8.3
PPT in.
0.57
6.58
2.46
10.1
83
112
151
200
253
97
333
181
191
4,7
301
281
163
175
-5.5
-11.8
-2.3
-4.0
260
85
137
-5.0
-41.5
-1.8
-3.5
226
256
8.3
12.0
3.08
4.5
8.1
-6.0
-22.7
-2.8
-4.7
-28.8
-2.3
-3.5
Dec
16.71
6.25
7.82
12.75
1.75
9.0
6.1
5.4
5.7
7.6
1.2
1.8
3.2
8.9
1.2
1.5
2.9
7.3
1.6
1.8
9.8
5.3
3.8
1.9
1.5
-14.7
-2.3
5.1
2.5
Jan
1.45
9,1
1.0
-3.5
-13.3
-0.5
-2.5
282
-20.5
-1.8
-3.5
278
4.5
DO 100
DO 100
DO 50
DO 25
4.5
-6.0
-49.5
-10.0
-8.5
-21.0
-20.0
279
310
413
PPT cm
1/25/97
0.8
0.8
D025-1
D025-2
D025-3
Corrected
Average
W-100
-4.5
1/20/97
-52.0
-58.0
D0100-1
D0100-2
D0100-3
D050-1
D050-2
D050-3
-6.0
1/11/97
-5.0
-82.5
-21.0
-21.0
P-100-3
E-100-1
Benton County
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
P-100-1
P-100-2
P-50-1
P-50-2
P-50-3
Site 4
11.25
6.8
1.3
1.4
1.3
273
WITHAM HILL DATA
Site 4
Benton County
11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
1/25/97
Saturation (gr
25 cm
50 cm
100 cm
Data Lines
(graphing)
2
350
200
5
3
2
350
200
5
3
3
2
3
2
3
2
3
2
2
3
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
350
200
5
350
200
5
350
200
5
350
200
350
200
5
5
350
200
5
350
200
5
350
200
5
350
200
5
Solution pH
pH 100
pH 50
pH 20
6.81
6.62
5.74
5.67
6.35
6.09
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100 C
P-100-1C
P-100-2C
P-100-3C
P-50-1C
P-50-2C
P-50-3C
P-25-1C
P-25-2C
P-25-3C
no
no
no
63
59.5
56
55.5
31
31
29.5
30
107.5
46
46
74.5
35
33.5
29.5
80
42
39.5
28.5
53.5
32
29.5
30.5
51.5
30
29
29.5
57.5
31.5
30
28.5
74
31.5
33.5
29
26
27.5
28
26
23
29.5
27.5
25.5
29
28
25.5
28
26.5
24
29
29.5
27
27.5
29
26
29.5
30
27.5
28.5
29
29.5
27.5
28.5
26
31
77
83
46
45
25.5
30
28
26
29
27
25
25
30
28
26
29.5
30.5
28.5
30
30.5
28.5
29
29.5
27
29
29.5
27
30.5
30.5
28
29.5
28
29
27
no
no
no
274
WITHAM HILL DATA
Site 4
Benton County
2/01/97
2108/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4112/97
-4.0
-38.0
-13.0
-5.0
-6.0
-35.0
-9.0
-6.0
-6.0
-36.5
-8.0
-6.5
-5.5
-34.5
-8.0
-6.5
-4.0
-31.5
-4.5
-5.5
-5.5
-30.5
-7.0
-5.0
-5.5
-37.5
-3.0
-3.5
-7.0
-32.5
-5.5
-5.5
-5.5
-27.5
-3.5
-2.5
-8.0
-37.0
-6.0
-4.5
-7.5
-35.0
-7.0
-6.0
P-50-1
P-50-2
P-50-3
-5.0
-1.0
-1.0
-5.5
-3.5
-2.0
-5.0
-1.5
-2.5
-4.5
-2.5
-2.0
-3.0
0.0
0.0
-3.5
-0.5
-1.5
-5.0
-2.0
-2.5
-5.5
-3.0
-2.5
-6.5
-3.0
-4.5
-6.0
-3.0
-4.0
-5.5
-4.5
-3.5
P-25-1
-6.0
-3.0
-2.5
-7.0
-4.0
-4.5
-6.5
-4.0
-5.0
-8.0
-5.5
-5.5
-6.5
-4.5
-1.5
-4.5
-4.5
-3.5
-5.0
-6.5
-4.5
-6.5
-4.0
-6.5
-7.0
-4.5
-5.0
-7.5
-5.5
-5.5
-6.0
-5.5
-4.5
E-100-1
15
43
-7
-87
-5
-9
-65
-25
16
11
6
-41
-9
-108
32
-3
-212
3
-57
-29
24
-36
-10
44
E-100-2
E-100-3
-5
8
-211
-215
2
-406
-270
-28
-193
-294
-181
-326
-34
-229
-359
-194
-208
9.2
9.6
9.5
15.3
-324
-44
-240
-345
11.6
-262
-59
-196
-220
-158
-196
8.7
8.6
8.5
13.3
10.3
10.0
9.9
-333
-50
-228
-109
-193
-235
10.7
10.2
9.5
18.9
-346
-72
-137
-197
-198
-178
8.5
8.4
8.4
Field Data
W-100
P-100-1
P-100-2
P-100-3
P-25-2
P-25-3
E-50-1
-169
E-50-2
E-50-3
-131
9
-14
-79
-204
-18
-154
-144
-74
-240
8.2
-231
-19
7.1
6.1
7.1
8.1
8.1
7.5
10.0
5.8
6.9
14.0
9.7
-193
-18
-207
-196
-133
-205
8.3
7.9
7.4
6.9
DO-W100
2.8
2.0
3.6
2.9
3.0
2.2
2.1
1.3
1.8
2.0
1.4
00100-1
00100-2
D0100-3
6.1
5.7
3.3
2.7
6.5
1.0
3.5
6.6
3.0
3.5
6.0
2.5
3.3
6.5
1.2
2.2
6.1
3.3
3.7
6.3
4.9
4.2
6.4
3.6
3.7
7.4
3.2
3.7
4.5
3.0
3.7
0050-1
D050-2
0050-3
1.3
1.6
0.8
2.0
0.8
0.9
1.5
1.0
1.2
1.3
0.9
1.2
0.8
1.1
1.1
1.4
0.6
0.5
0.9
1.0
1.2
0.9
0.8
1.1
1.1
1.2
0.9
0.9
0.8
0.5
D025-1
1.6
1.8
1.2
1.6
1.7
1.1
1.5
1.9
1.3
1.1
1.4
2.4
1.2
1.4
2.0
1.1
1.8
2.7
1.6
2.0
2.2
1.1
1.4
1.6
1.2
2.1
1.1
1.5
1.3
1.1
1.1
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
-4.0
-18.7
-2.3
-3.8
226
49
73
-6.0
-16.7
-3.7
-5.2
242
-5.5
-16.3
-3.0
-6.3
232
23
-60
-4.0
-13.8
-1.0
-4.2
223
47
-4
-5.5
-14.2
-1.8
-4.2
-5.5
-11.2
-4.7
-5.5
188
178
57
-17
-5.5
-14.7
-3.2
-5.3
216
14
-17
-7.0
-14.5
-3.7
-5.7
22
-6.0
-17.0
-3.0
-5.2
262
45
7
-10
-79
-16
-82
-8.0
-15.8
-4.3
-6.2
184
-17
-5
-7.5
-16.0
-4.5
-5.3
117
-29
-46
8.0
8.2
8.0
8.2
7.1
6.1
5.8
7.1
8.1
6.9
14.0
7.5
9.7
8.3
7.9
7.4
6.9
8.5
8.4
8.4
11.6
8.7
8.6
8.5
13.3
9.2
9.6
9.5
15.3
10.0
10.3
10.0
9.9
10.7
10.2
9.5
18.9
10.2
7.5
0.24
Feb
0.61
0.41
0.75
2.45
2.11
1.22
0.23
0.45
April
0.35
1.04
1.91
0.35
Mar
0.89
6.22
5.36
3.10
0.58
1.14
0.89
2.0
3.9
1.2
1.5
3.6
3.7
1.2
1.3
2.9
4.4
1.2
1.5
3.0
3.9
2.2
3.3
0.8
1.4
2.1
1.3
4.4
1.0
1.5
5.1
1.8
4.6
1.0
1.7
2.0
4.8
1.4
3.7
0.7
1.5
E-25-1
E-25-2
E-25-3
TC-100
TC-50
TC-25
AMBIENT
0025-2
0025-3
Corrected
Average
W-100
P-100
P-50
P-25
E-100
E-50
E-25
-114
-102
-57
-145
8.0
7.5
2.6
3.6
1.0
0.9
TC-100
TC-50
TC-25
AMBIENT
10.0
PPT in.
3.31
PPT cm
8.41
DO 100
DO 100
DO 50
DO 25
8.1
2.8
4.1
1.1
1.5
1.1
61
-175
-172
-99
-232
8.0
-121
-289
8.2
1.7
1.1
1.4
201
1.4
1.0
2.0
-191
-232
10.0
1.1
1.8
-61
-239
-213
-204
-245
10.2
10.1
9.6
14.0
10.1
9.6
14.0
275
WITHAM HILL DATA
Site 4
Benton County
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
3
2
3
3
2
3
2
3
2
3
2
3
2
2
3
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
1
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
5
350
200
350
200
5
Saturation (gr
25 cm
50 cm
100 cm
Data Lines
(graphing)
350
200
5
5
Solution pH
pH 100
pH 50
pH 20
A-A-Dip Test
40-60 cm
20-40 cm
0-20 cm
Raw PZ Data
W-100 C
P-100-1C
P-100-2C
P-100-3C
yes
no
no
29
63
38
30
31
31
60
34
31
61.5
33
31.5
P-50-1C
P-50-2C
P-50-3C
30.5
27.5
24.5
31
30.5
30
25.5
P-25-1C
P-25-2C
P-25-3C
30
29.5
27
31
30.5
29
30.5
59.5
yes
no
no
33
31.5
29
56.5
29.5
30.5
30.5
55.5
32
30
30.5
62.5
28
28.5
32
57.5
30.5
30.5
30.5
52.5
28.5
27.5
31
32.5
60
32
29.5
31
30
29
25.5
28.5
26.5
23.5
29
27
25
30.5
28.5
31
29.5
26
26
32
29.5
28
31.5
29.5
27.5
31
28
26
30.5
30.5
29.5
32
32
30
30.5
28.5
29
33
29
30.5
30.5
31
31
30
31
29.5
31.5
32
30
31
31
26
28
33
62
31
27
32
29
276
WITHAM HILL DATA
Site 4
Benton County
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
6/01/97
-3.0
-38.5
-6.0
-8.0
-8.5
-32.0
-7.0
-5.0
-5.5
-33.0
-6.5
-4.0
-21.0
-39.5
-13.5
-11.5
-53.0
-56.5
-40.0
-37.5
-79.0
-77.0
-77.0
-69.0
-22.0
-82.0
-59.5
-56.5
P-50-2
P-50-3
-4.5
-2.5
-3.5
-6.0
-2.5
-5.0
-4.0
-1.0
-2.5
-17.5
-14.5
-15.0
-46.0
-47.5
P-25-1
P-25-2
P-25-3
-6.0
-4.5
-3.0
-6.5
-6.5
-6.0
-5.5
-3.5
-2.0
-19.5
-16.5
-16.5
E-100-1
E-100-2
E-100-3
7
-38
-388
29
23
-368
11
-36
-388
57
3
-382
46
3
-382
E-50-1
E-50-2
E-50-3
E-25-1
E-25-2
E-25-3
-350
-44
-250
-193
-212
-365
-124
-63
-374
-261
-362
-360
-370
-55
-329
Field Data
W-100
P-100-1
P-100-2
P-100-3
P-50-1
TC-100
TC-50
TC-25
AMBIENT
-251
10.3
11.2
11.8
17.2
-61
-284
-163
-207
-262
11.4
-276
-230
-269
12.5
19.8
11.6
12.4
12.3
14.2
12.1
-1
-11
-268
12.2
13.5
-20.5
-15.5
-17.5
-20.0
-17.5
-19.0
-367
-369
28.8
-307
12.8
14.7
15.8
27.4
14.1
6/07/97
-360
55
-97
16
-45
47
-114
-216
-333
13.4
14.7
0
-67
-362
-22
0
24
-357
10
-234
13.5
15.1
15.4
16.0
22.4
2.4
1.5
4.8
3.8
3.8
15.1
DO-W100
1.4
1.4
1.3
1.2
0.4
D0100-1
4.0
3.8
3.3
2.7
4.5
2.3
3.7
4.7
6.0
4.1
D0100-3
2.2
4.8
4.9
5.5
5.7
0050-1
0.9
0.7
0050-2
0050-3
1.1
1.0
2.1
1.1
0.8
0.9
1.0
0.9
1.4
0.8
D025-1
1.7
1.2
1.2
1.1
1.1
2.3
1.6
1.2
0.7
0.9
2.1
1.7
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
6/01/97
-3.0
-17.5
-3.5
-4.5
-8.5
-14.7
-4.5
-6.3
-5.5
-14.5
-21.0
-21.5
-15.7
-17.5
-53.0
-44.7
-46.8
-79.0
-74.3
-22.0
-66.0
-17.8
-18.8
110
144
-50
-36
142
-59
-39
138
-65
-173
115
193
-47
106
187
-19
13.4
14.7
15.1
15.4
13.5
0.37
1.58
June
1.09
0.94
4.01
2.77
2.4
5.7
1.5
00100-2
0025-2
D025-3
Corrected
Average
W-100
P-100
P-50
P-25
E-100
E-50
E-25
-28
-44
3.1
2.8
TC-100
TC-50
TC-25
AMBIENT
10.3
11.2
11.8
17.2
11.4
PPT in.
0.68
1.88
PPT cm
1.73
1.4
4.0
1.4
1.4
DO 100
DO 100
DO 50
DO 25
-2.5
-3.7
112
37
-84
3.9
4.1
4.0
1.4
3.1
35
3.1
3.9
2.9
11.6
12.4
12.3
14.2
12.2
13.5
28.8
12.8
14.7
15.8
27.4
0.11
0
4.78
0.68
May
1.73
1.4
3.3
0.9
1.3
1.3
3.3
0.9
0.9
1.2
3.5
1.0
2.0
12.1
12.5
19.8
14.1
0.28
0.4
4.2
3.6
6/07/97
15.1
16.0
22.4
4.1
3.0
3.3
Benton County
Site A
WITHAM HILL DATA
10\10\95 10/17/95 10/24/95 10\31195 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95 12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
-90.0
-94.5
-48.0
-35.0
-74.0
-65.0
-26.5
-29.0
-28.0
13.0
10.8
9.8
10.7
10.0
10.6
3.26
4.09
2/02/96
2/09/96
Field Data
W-100
P-75-1
-75.9
-60.8
-46.2
-30.2
-32.6
-87.2
13.4
13.6
12.5
9.8
10.4
3.38
3.74
2.71
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
0.06
PPT in.
2.26
0.55
PPT cm
0.7
0.82
2.51
0.26
2.96
Nov
Oct
0.15
5.74
1.40
2.08
0.08
Dec
1.78
6.38
0.66
7.52
1.5
1.75
Jan
8.59
9.50
6.88
0.20
1.27
6.5
3.23
16.51
Feb
3.81
4.45
8.28
10.39
Saturation (graphing)
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
1
25.5
16.5
1
-57.0
52.0
3.0
1
13.6
116.0
120.5
74.0
85.0
1
100.0
115.0
52.5
79
67
2/17/96
2/23/96
3/01/96
Benton County
Site A
WITHAM HILL DATA
3/08/96
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
5/30/96
0.06
0.17
1.63
2.04
0.11
6/14/96
6/21/96
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
0.04
0.10
-36.5
-32.5
-81.0
10.8
9.8
5.9
0.55
March
11.38
1.40
4.48
1.73
0.43
0.2
0.7
0.98
0.78
0.72
2.9
April
4.39
1.09
0.51
1.78
May
2.49
1.98
1.83
7.37
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
62.5
82.5
107
0
0.1
June
0.15
0.43
4.14
5.18
0.28
0.25
6/28/96
Benton County
Site A
WITHAM HILL DATA
9/24196 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96 11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
0.75
1.91
0
0.39
0.99
1.37
3.48
2.17
Oct
1.39
5.51
3.53
0.45
0.57
6.58
2.46
Nov
-46.5
-35.5
-54.5
-45.0
7.9
8.1
6.1
8.1
3.08
5.02
-66.5
-61.0
0.69
4.43
-26.5
-29.0
-28.0
-75.5
-67.5
10.7
10.0
10.6
9.6
9.7
6.8
Dec
1.14
1.45
16.71
6.25
0.52
2.25
1.32
5.72
Jan
7.82
12.75
1.75
11.25
17.27
Saturation (gr
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
2
1
72.5
85.5
1
1
80.5
95
92.5
111
1
52.5
79
67
1
101.5
117.5
1/25/97
2/01/97
Benton County
Site A
WITHAM HILL DATA
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
0,35
Mar
0.89
2.45
2.11
1.22
0.23
0.35
0.68
1.88
0
0.37
5.36
3.10
0.58
0.89
1.73
4.78
0.68
May
1.73
0.11
6.22
0.45
April
1.14
Field Data
-49.0
-38.0
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
9.3
10.0
0035-1
D020-1
PPT in.
0.8
3.31
0.24
Feb
0.41
0.75
PPT cm
2.03
8.41
0.61
1.04
1.91
Saturation (g o
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
1
75
88
0.28
0.94
WITHAM HILL DATA
6/01/97
6/07/97
1.58
June
1.09
4.01
2.77
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
0035-1
0020-1
PPT in.
PPT cm
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
Site A
Benton County
Benton County
Site B
WITHAM HILL DATA
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95 12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
-23.3
-17.3
12.0
13.9
9.3
7.4
-14.1
9.9
PPT in.
0.06
2.26
0.55
0.7
0.82
2.51
0.26
2.96
Nov
Oct
PPT cm
-46.2
-22.4
-31.9
0.15
5.74
1.40
2.08
3.38
-9.8
-15.5
-11.7
-8.6
-20.8
-12.9
-15.2
-68.9
-48.7
-18.5
-16.0
-17.0
-18.5
-22.5
-17.0
-19.5
-7.5
-11.0
-10.5
-13.5
-9.0
-13.0
-12.5
-14.0
-30.5
-22.5
-27.5
-11.5
-12.5
-12.5
-11.0
8.3
4.0
5.7
9.0
5.8
1.6
2.9
5.8
7.0
1.4
7.1
11.9
2.8
7.3
3.6
6.0
1.6
4.0
6.2
3.4
3.2
6.9
3.4
4.6
3.74
2.71
0.08
3.26
4.09
2.7
Dec
1.78
6.38
0.66
9.9
1.6
3.9
1.5
1.75
Jan
7.52
8.59
9.50
6.88
2
2
3
2
2
1
1
1
1
0.20
4.4
6.0
1.27
6.5
Feb
3.81
4.45
8.28
10.39
3.23
16.51
47.0
66.0
49.5
32.0
60.0
40.5
42.5
33.5
82.0
42.5
43.0
55.0
71.5
57.5
36
61.5
42.5
40
Saturation (graphing)
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
57.0
61.0
3.6
81.3
70.6
20.5
95.6
69.0
27.0
13.2
3
84.0
72.0
23.0
2
1
1
33.0
30.5
43.0
65.0
47.0
47.5
Site B
WITHAM HILL DATA
2/17/96
2/23/96
3/01/96
3/08/96
3/15/96
3/23/96
3/30/96
4/04/96
-42.5
-30.0
-8.0
-11.0
-12.0
-13.5
-40.5
-31.0
-26.5
-16.5
-22.5
-59.5
-45.5
-82.0
-63.0
-99.0
-97.0
4.3
3.4
7.5
2.3
3.5
1.8
4.8
1.4
2.3
1.0
1.4
2.2
0.55
March
11.38
1.40
1.73
0.43
0.2
4/11/96
Benton County
4/18/96
4/25/96
5/04/96
-96.0
-74.5
-10.5
-16.0
-13.0
-14.0
4.3
2.9
2.3
2.6
2.2
5/09/96
5/16/96
5/24/96
5/30/96
-75.5
-58.0
-95.5
-43.0
-40.0
-89.0
-77.0
2.3
6.4
1.2
2.3
1.7
3.4
1.63
2.04
0.11
6/14/96
6/21/96
0
0.1
Field Data
W-100
P-75-1
P-35-1
P-20-1
D0 -W100
0075-1
2.7
2.6
D035-1
0020-1
PPT in.
PPT cm
0.04
0.10
4.48
2.0
0.7
0.98
0.78
0.72
1.09
0.51
1.78
0.06
2.9
April
4.39
3.1
0.17
May
2.49
1.98
1.83
7.37
June
0.15
0.43
4.14
5.18
0.28
Saturation (gr
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
3
2
1
1
67.0
79.0
32.5
60.0
42.0
42.5
3
2
1
65.0
80.0
1
51.0
65.5
52.5
2
1
84.0
94.5
1
106.5
112.0
123.5
121.5
1
1
1
120.5
123.5
35
65
43
43
100
107
1
120
67.5
89
1
113.5
126
0.25
6/28/96
Benton County
Site B
WITHAM HILL DATA
9/24/96 10/03196 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96 11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
-11.5
-12.5
-12.5
-11.0
-66.0
-52.5
-13.0
-15.5
-14.5
-14.0
6.0
2.5
1.6
1.8
5.9
1.2
8.5
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT In.
PPT cm
-30.5
-21.5
-24.0
-48.0
-34.5
-17.0
-15.0
-14.5
-17.0
-16.0
-15.0
-15.0
-16.5
-59.5
-46.5
10.2
9.0
6.7
5.1
5.1
2.0
5.5
8.3
5.2
1.0
4.7
6.7
2.6
2.7
3.08
5.02
0.69
9.1
0.75
1.91
0
0.39
0.99
1.37
3.48
2.17
Oct
1.39
5.51
3.53
0.45
0.57
6.58
2.46
Nov
-17.0
-17.0
-16.0
-16.5
4.4
6.0
4.43
6.8
Dec
1.14
1.45
16.71
6.25
8.1
0.52
2.25
1.32
5.72
Jan
7.82
12.75
3
2
1
1
11.25
17.27
3
3
3
2
2
2
1.75
Saturation WI
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
2
1
55
70.5
54
1
72.5
83.5
41.5
64
44.5
46
40.5
64
45
45.5
1
84
95.5
1
41.5
66
46
45.5
1
36
61.5
42.5
40
2
1
1
90.5
101.5
37.5
64.5
44.5
43
Benton County
Site B
WITHAM HILL DATA
1/25/97
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
4/26/97
5/03/97
-18.0
-17.5
-17.5
-18.0
-11.5
-15.0
-16.0
-13.5
-40.5
-32.0
-58.0
-47.5
-47.5
-36.5
-31.0
-21.5
-23.5
-22.5
-18.5
-19.0
-23.5
-18.0
-20.0
-33.5
-23.0
-29.0
-67.0
-52.0
-86.0
-68.5
-99.5
-25.5
-22.0
-23.0
-59.0
-47.0
6.5
1.2
8.1
1.0
3.9
2.3
1.3
2.6
1.2
2.9
4.3
4.8
0075-1
1.0
1.1
2.0
0.8
3.2
0.9
2.7
2.9
D035-1
D020-1
7.1
7.1
3.7
11.1
4.5
1.2
2.6
5.1
2.8
0.8
1.1
1.2
3.1
PPT in.
0.8
3.31
2.45
2.11
1.22
0.23
PPT cm
2.03
8.41
0.35
Mar
0.89
6.22
5.36
3.10
0.58
4/18/97
5/10/97
5/16/97
5/24/97
0
0.37
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
1.1
0.24
Feb
0.61
0.41
0.75
1.04
1.91
4.5
1.9
0.45
April
1.14
0.35
0.68
1.88
0.89
1.73
4.78
0.68
May
1.73
Saturation (gr
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
3
2
2
2
2
1
1
1
1
42.5
66.5
47.5
47
36
65
64
81
46
42.5
82.5
96.5
72
85.5
55.5
70.5
53.5
47
67.5
49
48
67
50
58
72
59
2
1
91.5
101
1
110.5
117.5
1
124
50
71
53
1
83.5
96
0.11
0.28
0.94
WITHAM HILL DATA
6/01/97
6/07/97
1.58
1.09
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT In.
June
PPT cm
Saturation (gr
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
4.01
2.77
Site B
Benton County
Site C
WITHAM HILL DATA
10 \ 10 \ 95
10/17/95 10/24/95
Field Data
W-100
10 \ 31 \ 95 11 \ 07 \ 95
-95.3
-96.7
11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95 12/26/95
-77.1
-64.2
P-75-1
P-35-1
P-20-1
-79.5
-69.0
8.3
0.06
2.26
0.55
0.7
0.82
2.51
0.26
0.15
5.74
1.40
2.08
6.38
0.66
1/26/96
2/02/96
2/09/96
-7.5
-7.5
-5.5
-7.5
-6.0
-4.5
-4.5
-6.5
-1.0
-1.5
0.0
-2.5
-1.0
-1.5
-1.0
-2.5
-6.5
-3.0
-4.0
-5.5
-3.0
-3.0
-1.5
-4.5
2.3
1.6
7.2
3.1
4.8
2.5
3.5
3.3
4.1
4.4
4.09
1.27
6.5
-28.3
9.5
8.1
2.6
4.6
2.0
2.7
3.7
1.1
3.1
1.8
1.7
2.8
1.3
1.7
5.9
5.1
2.1
2.0
1.6
1.9
2.4
3.7
7.8
2.4
2.5
4.2
3.38
3.74
2.71
1.5
1.75
3.26
2.96
-24.1
-25.9
0.08
Dec
1.78
1/19/96
-5.7
-1.7
-4.0
-5.3
Nov
Oct
1/12/96
-4.7
-4.3
-2.7
-3.2
8.6
0035-1
0020-1
1/02/96
-9.0
-3.4
-7.4
-7.9
-12.2
DO-W100
D075-1
PPT cm
-15.5
-10.3
-10.1
PPT in.
Benton County
4.2
3.8
Jan
7.52
8.59
9.50
6.88
3
2
3
3
3
2
2
2
2
1
1
1
1
1
89.6
75.0
28.9
9.0
96.5
83.0
32.0
14.0
0.20
1.1
1.1
Feb
3.81
4.45
8.28
10.39
3.23
16.51
3
3
2
3
3
2
2
3
2
3
2
1
1
1
1
1
1
Saturation (graphing)
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
1
3.5
5.0
24.3
12.5
21.7
7.0
101.0
82.0
37.5
19.5
100.0
85.0
36.0
17.0
76.0
59.0
10.5
31.5
56.0
45.0
37.0
30.0
53.0
44.0
36.0
25.0
50.0
39.5
32.0
25.0
50.0
40.5
32.0
30.5
51.5
43.5
35.0
27
51.5
41
34
Benton County
Site C
WITHAM HILL DATA
2/17/96
2/23/96
3/01/96
3/08/96
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
5/30/96
6/14/96
-12.5
-9.5
-8.0
-8.5
-1.0
-0.5
-0.5
-2.5
-10.0
-6.0
-3.5
-4.5
-4.5
-24.5
-25.0
-26.5
-34.0
-33.5
-33.5
-45.5
-43.5
-44.5
-43.0
-65.0
-62.5
-37.5
-32.5
-29.0
-5.0
-4.5
-4.0
-6.0
-27.0
-32.5
-35.5
-55.0
-51.5
-37.5
-32.5
-30.0
-22.0
-18.0
-17.5
-19.0
-46.0
-41.5
-98.5
1.7
2.5
4.5
1.2
1.2
2.9
1.5
2.0
1.6
1.2
1.4
2.3
1.2
1.2
1.2
1.5
1.2
2
1.7
2.3
1.6
1.6
3.6
1.0
1.3
1.4
1.3
3.1
1.8
1.5
1.9
1.3
1.3
3.6
1.3
1.5
1.6
1.2
1.2
1.73
0.43
0.72
2.9
0.17
1.63
2.04
0.11
6/21/96
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
3.1
3.5
0.04
0.10
-9.0
-10.0
-8.5
1.9
3.2
2.1
0.2
0.55
March
1.40
11.38
4.39
1.09
0.51
4.48
0.7
0.98
0.78
April
1.78
4.5
0.06
May
2.49
1.98
0.1
June
1.83
7.37
0.15
2
3
2
2
1
1
1
1
51
79
100
0.43
4.14
5.18
0.28
0.25
Saturation (g
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
3
2
3
2
3
2
3
2
2
2
1
1
1
1
1
1
36.5
58.0
47.5
38.0
25.0
49.0
40.0
32.0
34.0
57.5
49.5
38.0
30.0
52.0
44.0
34.0
48.5
73.5
66.0
58.0
82.0
73.0
1
1
1
69.5
92
68.5
91.5
89
61.5
111
81
68.5
29
53
43.5
35.5
81
75
2
1
61.5
81
69.5
46
66.5
57
48.5
1
70
90
122.5
6/28/96
Benton County
Site C
WITHAM HILL DATA
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96 11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
-3.0
-3.0
-1.5
-4.5
-30.0
-30.0
-30.0
-9.0
-19.0
-6.5
-8.5
4.1
0.9
1.8
5.3
2.3
0.9
1.0
3.8
0.52
2.25
1.32
5.72
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
-13.5
-11.5
-9.5
-13.5
-25.0
-21.5
-18.5
-10.5
-8.0
-7.0
-10.5
-8.5
-6.5
-5.5
-9.5
-28.5
-27.0
-27.0
10.8
5.8
5.6
4.5
3.6
1.2
3.0
1.5
1.5
1.7
4.2
9.1
7.7
8.5
0.75
1.91
0
0.39
0.99
1.37
3.48
2.17
Oct
1.39
5.51
3.53
0.45
0.57
6.58
2.46
Nov
1.1
1.1
5.6
4.9
3.08
5.02
-8.0
-7.5
-6.0
-7.5
1.1
1.1
4.4
0.69
4.43
6.8
Dec
1.14
1.45
16.71
6.25
Jan
7.82
12.75
1.75
11.25
17.27
Saturation (g
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
3
3
2
2
2
2
3
2
3
2
2
2
2
1
1
1
1
1
1
1
1
1
27
51.5
54
78.5
69.5
3
37.5
60
49
43
49
70
58
34.5
56.5
46.5
40
32.5
55
45
39
52.5
75.5
66.5
32
56
45.5
37
41
34
3
33
67.5
46
38
Site C
WITHAM HILL DATA
Benton County
1/25/97
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
-9.5
-8.5
-7.5
-7.5
-7.5
-6.0
-3.5
-7.0
-50.0
-18.5
-18.5
-29.5
-30.0
-29.5
-25.0
-25.5
-25.5
-4.5
-6.5
-4.5
-6.5
-8.5
-5.5
-6.5
-7.0
-9.5
-8.5
-8.0
-8.5
-13.0
-12.5
-11.5
-14.0
-30.5
-35.0
-33.5
-46.0
-46.5
-57.0
-54.0
-63.0
-59.5
-10.5
-12.5
-11.5
-14.5
-32.0
-27.0
-25.0
-65.0
-60.0
-89.0
DO-W100
D075-1
D035-1
D020-1
3.6
0.7
2.5
1.6
1.3
1.8
0.7
0.7
1.3
1.9
6.1
1.0
1.3
1.9
1.0
1.2
1.9
1.0
1.0
1.5
1.1
1.1
1.1
1.8
0.9
0.8
1.0
1.6
1.5
0.7
1.0
2.2
1.0
2.0
3.1
1.4
4.9
2.9
1.0
1.7
2.5
2.1
1.0
1.2
1.6
PPT in.
0.8
3.31
0.24
0.41
0.75
2.11
1.22
0.23
0.45
April
0.35
0.68
1.88
0
8.41
1.04
1.91
6.22
5.36
3.10
0.58
1.14
0.89
1:73
4.78
0.68
May
1.73
0.11
2.03
0.35
Mar
0.89
2.45
Feb
0.61
3
3
2
2
2
2
3
2
3
2
3
2
2
3
2
2
1
1
1
1
1
1
1
1
1
1
37
54.5
83.5
73
5/24/97
Field Data
W-100
P-75-1
P-35-1
P-20-1
PPT cm
1.3
1.1
3.4
8.9
0.8
1.3
1.7
0.28
0.94
Saturation (g
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
33.5
57
47
37
31.5
54.5
43
36.5
74
67
58
53.5
78.5
69
49
74
65
28.5
55
44
36
32.5
54
46
36.5
33.5
57
47.5
38
61
51
43.5
3
1
70
95
2
2
1
1
1
1
81
87
108
34.5
56
75.5
64.5
102.5
61
51
44
1
89
108.5
0.37
113
WITHAM HILL DATA
6/01/97
6/07/97
1.58
June
4.01
1.09
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
0075-1
D035-1
0020-1
PPT in.
PPT cm
Saturation (g
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
2.77
Site C
Benton County
Site D
WITHAM HILL DATA
10 \ 10 \ 95
10/17/95 10/24/95 10 \ 31 \95
11 \ 07 \ 95
Benton County
11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95 12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
6.9
6.4
2/02/96
2/09/96
1.0
0.0
-58.0
-5.5
-3.0
-58.0
-6.0
-4.0
0.0
-62.5
-4.5
-0.5
Field Data
-85.8
W-100
P-75-1
P-35-1
P-20-1
-76.9
-84.2
-34.3
-74.2
8.0
DO-W100
D075-1
D035-1
D020-1
-3.8
-70.9
-6.6
-2.8
-0.9
0.06
2.26
0.55
0.82
7.4
0.7
2.51
0.26
2.96
Nov
0.15
5.74
1.40
2.08
-2.8
-53.0
-5.7
-0.2
-6.6
-49.8
-10.9
-6.6
-3.0
-55.0
-8.0
-7.0
-1.0
-51.0
-6.0
-5.0
0.0
-55.0
-4.0
-3.0
8.3
7.0
3.9
2.7
6.5
4.8
7.9
6.9
3.5
6.1
9.1
7.1
1.8
3.8
1.5
2.7
4.8
2.0
2.9
7.9
2.8
3.4
5.0
6.8
7.4
8.3
2.6
3.3
3.38
3.74
2.71
1.5
1.75
3.26
4.09
-5.7
-1.9
7.8
Oct
0.0
-49.0
-5.3
-1.0
-55.1
10.1
PPT in.
PPT cm
-47.2
6.1
3.4
0.08
Dec
1.78
6.38
0.66
Jan
3.2
2.7
6.4
1.9
7.9
1.27
6.5
3.1
Feb
7.52
8.59
9.50
6.88
0.20
3.81
4.45
8.28
10.39
3.23
16.51
3
2
3
2
3
2
3
3
2
3
2
3
2
3
2
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
1
106.0
32.0
34.5
22.0
103.0
27.0
34.0
23.0
Saturation (graphing)
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
1
15.0
24.5
16.8
69.6
1.0
56.0
102.0
5.0
33.0
20.0
105.0
24.5
34.0
21.0
99.0
31.0
28.0
15.5
17.0
104.0
48.0
36.0
15.0
100.0
46.0
34.0
14.0
104.0
44.0
32.0
13.0
107.0
45.5
32.0
14.0
107.0
46.0
33.0
14
111.5
44.5
29.5
Site D
WITHAM HILL DATA
Benton County
2/17/96
2/23/96
3/01/96
3/08/96
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
5/30/96
6/14/96
6/21/96
-1.0
-43.5
-7.5
-5.5
0.0
-58.5
-5.0
-3.0
-1.0
-60.0
-7.5
-6.0
-1.0
-61.0
-6.0
-4.0
-7.0
-59.5
-13.5
-11.5
-5.0
-61.0
-13.5
-10.0
-17.0
-65.0
-13.5
-19.5
-16.0
-58.5
-22.5
-17.5
-39.0
-71.0
-2.5
-66.0
-10.5
-6.0
0.5
-61.0
-6.0
-3.0
-23.0
-64.0
-29.0
-45.0
-60.0
-7.0
-69.0
-15.0
-11.0
-5.0
-60.0
-11.0
-7.5
-32.5
-66.0
-84.5
-97.5
3.3
7.3
3.3
2.3
5.6
5.5
3.4
2.3
4.8
4.5
2.2
3.5
1.5
5.5
1.8
3.8
1.7
4.8
4.7
3.9
1.5
1.7
2.2
4.4
2.0
2.3
1.2
3.2
1.7
1.4
2.7
2.3
1.4
5.2
2.0
1.9
0.55
March
11.38
1.40
1.73
0.43
0.72
2.9
1.63
2.04
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
0.04
0.10
4.48
1.9
1.4
1.6
1.7
1.3
4.3
4.3
2.3
4.3
4.3
1.4
1.9
0.2
0.7
0.98
2.1
0.78
April
2.1
4.3
0.06
0.17
1.8
0.11
May
4.39
1.09
0.51
1.78
2.49
1.98
0
0.1
June
1.83
7.37
0.15
3
2
3
2
2
1
1
1
0.43
4.14
5.18
3
2
3
2
1
1
0.28
0.25
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
15.0
92.5
47.5
34.5
14.0
107.5
45.0
32.0
15.0
109.0
47.5
35.0
15.0
110.0
46.0
33.0
21.0
108.5
53.5
40.5
19.0
110.0
53.5
39.0
31
114
53.5
48.5
30
107.5
62.5
46.5
1
53
120
16.5
115
50.5
35
13.5
110
46
32
37
113
69
1
59
109
21
118
55
40
19
109
51
36.5
1
46.5
115
98.5
111.5
Site D
WITHAM HILL DATA
6/28/96
Benton County
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96 11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
0.0
-62.5
-4.5
-0.5
-6.0
-61.0
-13.5
-8.0
-1.0
-68.5
-6.5
-4.5
2.7
6.4
1.9
7.9
1.7
7.4
2.0
1.9
1.9
8.2
1.5
3.0
0.52
2.25
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
0.75
1.91
0
0.39
0.99
1.37
3.48
2.17
Oct
1.39
5.51
3.53
0.45
0.57
-2.0
-23.0
-8.0
-4.0
-5.0
-64.5
-13.5
-9.5
-1.0
-74.0
-6.5
-4.0
-1.0
-72.0
-6.5
-2.5
-5.5
-69.5
-14.0
-9.0
8.8
8.6
8.9
5.6
1.8
9.0
1.5
6.1
3.1
2.6
8.4
1.3
3.6
4.7
3.6
7.8
2.2
2.7
6.58
2.46
3.08
5.02
0.69
5.3
3.6
Nov
-1.0
-70.5
-7.0
-3.0
4.43
6.8
Dec
1.14
1.45
Jan
16.71
6.25
7.82
12.75
1.75
11.25
17.27
1.32
5.72
3
2
3
2
3
3
3
2
2
3
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
15
19.5
118.5
54
38
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
16
19
72
48
33
113.5
53.5
38.5
15
123
46.5
33
121
46.5
31.5
15
119.5
47
32
14
111.5
44.5
29.5
20
110
53.5
37
2
15
117.5
46.5
33.5
Site D
WITHAM HILL DATA
Benton County
1/25/97
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
5/24/97
-1.5
-70.5
-7.0
-5.0
-1.0
-69.0
-7.0
-3.0
-3.5
-68.5
-12.0
-6.5
-6.5
-69.5
-14.0
-10.0
-6.0
-69.5
-13.0
-8.5
-1.0
-69.5
-9.0
-3.0
-2.0
-67.0
-7.5
-2.5
-2.5
-70.0
-8.0
-7.0
-4.0
-70.0
-10.0
-6.5
-6.5
-70.0
-14.0
-10.5
-14.5
-72.0
-20.5
-17.0
-20.0
-70.0
-25.5
-16.0
-71.0
-24.0
-7.5
-71.0
-14.0
-10.5
-7.0
-71.0
-15.0
-10.0
-38.0
-72.5
-68.0
-92.5
DO-W100
D075-1
D035-1
D020-1
3.3
9.2
1.6
1.6
1.5
8.3
8.7
2.8
2.8
10.2
1.8
1.4
1.3
8.2
1.7
1.3
1.0
8.9
2.0
2.0
7.0
2.6
1.8
1.0
5.0
1.5
1.2
1.9
1.6
3.5
3.2
1.5
6.1
1.7
1.2
PPT in.
0.8
3.31
0.41
0.75
0.35
0.68
1.88
0.37
2.03
8.41
1.04
0.89
1.73
4.78
0.68
May
1.73
0
PPT cm
0.24
Feb
0.61
3
2
3
3
2
2
1
1
1
Field Data
W-100
P-75-1
P-35-1
P-20-1
1.1
1.1
1.1
1.0
1.1
2.1
8.3
1.8
1.4
8.6
1.7
1.7
9.0
1.9
1.2
7.5
2.1
8.3
2.0
1.3
1.5
6.7
3.5
2.3
2.45
2.11
1.22
0.23
1.91
0.35
Mar
0.89
6.22
5.36
3.10
0.58
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
1
1
1
30
120
64
21.5
21
120
54
39.5
120
55
39
52
121.5
1.1
0.45
April
1.14
6.1
5.9
0.11
0.28
0.94
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
15.5
119.5
47
34
15
118
47
32
17.5
117.5
52
35.5
20.5
118.5
54
39
20
118.5
53
37.5
15
118.5
49
32
16
116
47.5
31.5
16.5
119
48
36
18
20.5
28.5
119
50
119
54
121
35.5
39.5
60.5
46
34
119
65.5
2
82
106.5
WITHAM HILL DATA
6/01/97
6/07/97
Field Data
W-100
P-75-1
-24.0
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
4.7
1.58
June
1.09
4.01
2.77
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
38
Site D
Benton County
Site E
WITHAM HILL DATA
Benton County
10\10\95 10/17/95 10/24/95 10\31\95 11\07\95 11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95 12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
-11.0
-6.5
-7.5
-2.5
-8.5
-4.5
-6.0
-1.0
-3.0
-2.5
-3.0
0.0
-2.0
-3.0
-3.0
-0.5
-11.0
-5.5
-7.5
-2.0
-2.0
-1.5
-2.5
2.5
6.5
5.5
2.4
14.2
9.5
3.3
5.5
10.6
4.9
2.4
3.9
4.8
5.7
3.3
3.2
7.2
1.5
7.3
7.3
2.9
3.2
1.5
1.75
3.26
4.09
1.27
6.5
Field Data
W-100
-72.6
P-75-1
P-35-1
P-20-1
-49.1
11.3
DO-W100
D075-1
D035-1
D020-1
-8.2
-1.4
-2.0
0.6
-4.7
-2.2
-2.9
2.6
-3.8
-3.0
-2.0
-8.5
-6.9
-3.9
1.7
1.7
6.8
4.8
9.5
4.9
1.7
3.7
9.4
5.0
1.6
3.5
6.9
5.4
1.9
3.4
5.1
3.38
3.74
2.71
0.08
3.1
2.8
PPT in.
0.06
2.26
0.55
0.7
0.82
2.51
0.26
2.96
0.15
5.74
1.40
2.08
-15.1
-10.3
-11.4
-9.2
6.9
2.3
4.7
Dec
Nov
Oct
PPT cm
-70.8
-52.8
1.78
6.38
0.66
Jan
3.1
1.2
1.6
Feb
7.52
8.59
9.50
6.88
0.20
3.81
4.45
8.28
10.39
3.23
16.51
Saturation (graphing)
20 cm
35 cm
75 cm
1
Raw PZ Data
W-100
29.0
30.0
P-75-1
P-35-1
P-20-1
1.06
1
31.0
25.8
3
3
3
2
2
3
2
3
2
3
2
3
2
2
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
1
1
36.0
55.0
48.5
33.5
33.5
53.0
47.0
32.0
27.0
51.5
44.0
31.5
36.0
54.0
48.5
33.0
97.3
85.4
35.0
21.8
101.0
84.5
34.0
24.0
102.0
83.5
35.0
23.0
97.0
79.0
33.0
23.0
90.0
75.0
25.0
11.5
28.0
51.0
44.0
31.0
27
50
43.5
28.5
Site E
WITHAM HILL DATA
Benton County
2/17/96
2/23/96
3/01/96
3/08/96
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
5/30/96
-5.5
-5.0
-5.0
-2.5
-1.0
-2.5
-2.0
-13.0
-8.0
-10.0
-6.0
-9.5
-4.5
-6.5
-2.5
-19.0
-14.0
-17.0
-15.0
-17.0
-20.5
-16.0
-14.0
-30.0
-23.0
-29.0
-27.0
-19.5
-25.0
-50.5
-49.5
-7.0
-11.0
-8.5
-3.5
-13.5
-4.5
-4.0
-1.0
-30.0
-34.5
-58.5
-55.5
-12.5
-18.5
-8.5
-9.0
-13.0
-8.0
-12.5
-8.0
-45.5
-35.5
DO-W100
D075-1
D035-1
D020-1
4.3
4.9
3.3
3.5
7.6
3.9
1.6
2.5
4.8
3.4
2.0
3.1
1.2
1.9
1.3
1.6
3.0
1.4
4.1
4.0
4.0
2.9
1.5
3.6
2.0
5.8
1.5
2.6
2.2
3.8
2.3
4.8
1.6
4.8
1.4
2.1
3.5
1.7
1.4
2.2
1.3
5.8
1.7
2.9
4.3
2.3
1.9
14.2
1.8
3.7
PPT in.
0.04
0.55
March
11.38
1.40
1.73
0.43
0.2
0.72
2.9
1.63
2.04
6/14/96
6/21/96
0
0.1
Field Data
W-100
P-75-1
P-35-1
P-20-1
PPT cm
Saturation (En
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
0.10
1.0
4.48
0.7
0.98
4.39
1.09
0.51
1.78
2.49
3
2
3
2
3
3
2
2
3
2
2
2
1
1
1
1
1
1
1
1
42.0
69.0
57.0
45.0
55
71.5
70
26.0
51.0
43.0
30.0
38.0
56.5
51.0
37.0
34.5
53.0
47.5
33.5
44.0
62.5
58.0
46.0
0.06
0.17
0.11
May
3
2
30.5
53.5
46.0
33.5
0.78
April
1.0
52
68
66
1.98
1
75.5
98
1.83
7.37
3
2
3
2
1
1
32
59.5
49.5
34.5
38.5
53
45
32
June
0.15
1
55
83
0.43
1
83.5
104
4.14
5.18
3
2
3
1
1
1
38
70.5
84
37.5
67
49.5
40
0.28
2
56.5
53.5
39
0.25
Site E
WITHAM HILL DATA
6/28/96
Benton County
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10/31/96 11/07/96 11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1111197
1/20/97
-2.0
-1.5
-2.5
2.5
-13.0
-11.0
-12.5
-7.5
-4.5
-5.0
-5.0
-12.5
3.9
Field Data
-3.5
-11.0
-5.5
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
0.75
1.91
0
0.39
0.99
1.37
3.48
2.17
Oct
1.39
5.51
3.53
0.45
0.57
-4.0
-3.5
-5.0
1.0
-3.5
-3.0
-4.5
1.0
-11.5
-9.5
-11.5
-7.0
1.0
-13.0
-10.5
-12.0
-8.0
8.9
8.3
5.2
4.8
3.8
3.9
1.5
1.6
4.8
3.8
4.9
3.0
7.2
4.9
3.1
2.7
2.5
1.1
4.1
1.0
1.8
1.4
2.1
1.2
1.6
1.2
1.2
1.6
0.9
1.8
6.58
2.46
3.08
5.02
0.69
0.52
2.25
Nov
1.1
-4.5
-4.0
-5.0
-1.0
4.43
6.8
Dec
1.14
1.45
Jan
16.71
6.25
7.82
12.75
1.75
11.25
17.27
1.32
5.72
3
3
2
3
2
3
2
3
3
2
2
2
3
2
3
2
3
2
1
1
1
1
1
1
1
1
1
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
28.5
59.5
46.5
30
36.5
58
52.5
38
29
52
46
30
28.5
51.5
45.5
30
38
59
53
39
29.5
52.5
46
32
27
50
43.5
28.5
38
59.5
53.5
38.5
29.5
53.5
46
43.5
Site E
WITHAM HILL DATA
Benton County
1/25/97
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
-4.0
-7.0
-3.5
-0.5
-5.0
-3.0
-5.0
-0.5
-13.0
-10.5
-12.0
-6.5
-18.0
-13.5
-16.0
-11.0
-17.0
-12.5
-15.5
-10.0
-2.5
-6.0
-6.5
-2.0
-3.5
5.0
-5.0
-0.5
-8.0
-6.0
-10.0
-1.0
-15.5
-10.0
-13.0
-8.5
-20.0
-14.5
-19.0
-12.5
-30.0
-22.5
-28.0
-35.0
-27.0
-31.5
-30.0
-25.0
-28.5
-21.5
-13.0
-20.0
-13.0
-21.5
-15.5
-18.0
-13.0
-53.5
-46.0
-77.0
-75.0
DO-W100
D075-1
6.9
1.5
4.5
1.9
1.6
2.0
7.0
2.6
1.5
1.9
0.8
3.2
6.2
2.3
1.1
1.1
2.0
1.0
0.9
1.5
1.7
2.2
0.8
2.3
1.3
1.0
1.2
2.4
1.2
1.0
1.2
1.3
1.2
1.0
1.3
2.4
1.7
1.0.
1.0
7.7
1.3
0.7
1.0
4.2
1.1
1.7
1.5
1.0
1.0
4.4
0035-1
0020-1
2.1
1.6
1.1
0.41
0.75
2.45
2.11
1.22
0.23
0.68
1.88
0
6.22
5.36
3.10
0.58
0.89
1.73
4.78
0.68
May
1.73
0.11
1.91
0.45
April
1.14
0.35
1.04
0.35
Mar
0.89
3
5/24/97
Field Data
W-100
P-75-1
P-35-1
P-20-1
1.4
1.6
1.0
1.2
PPT in.
0.8
3.31
PPT cm
2.03
8.41
0.24
Feb
0.61
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
2
2
2
2
2
3
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0.9
1.1
1.5
1.7
0.28
0.94
Saturation (gr
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
29
55.5
44.5
31.5
30
51.5
46
31.5
38
59
53
37.5
43
62
57
42
42
61
56.5
41
27.5
54.5
47.5
33
28.5
43.5
33
54.5
40.5
58.5
46
31.5
51
54
39.5
32
45
63
60
43.5
3
55
71
69
60
75.5
72.5
55
73.5
69.5
46.5
61.5
61
44
46.5
64
59
44
1
78.5
94.5
0.37
1
102
123.5
WITHAM HILL DATA
6/01/97
6/07/97
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
PPT cm
-63.5
-61.0
4.7
6.6
1.58
June
1.09
4.01
2.77
Saturation (9,
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
1
88.5
109.5
Site E
Benton County
Site F
WITHAM HILL DATA
10 \ 10 \ 95
10/17/95 10/24/95
10 \ 31 \ 95 11 \ 07 \ 95
Benton County
11/14/95 11/21/95 11/28/95 12/05/95 12/12/95 12/19/95 12/26/95
1/02/96
1/12/96
1/19/96
1/26/96
2/02/96
2/09/96
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
0075-1
-55.7
-54.9
-6.6
-4.9
-6.5
-4.7
-4.2
-2.2
-1.3
-3.6
-4.7
-5.2
-0.0
-1.9
-12.3
-12.9
-5.7
-8.8
-23.6
-23.3
-22.8
-17.5
-17.0
-15.0
-17.0
-16.5
-16.0
-13.0
-16.0
-4.5
-3.0
-0.5
-3.0
-8.0
-7.5
-5.0
-7.0
-26.5
-28.0
-25.0
-4.5
-4.0
-1.5
-3.5
8.9
12.3
9.5
5.5
4.1
3.8
2.9
2.3
2.5
3.5
4.6
4.6
3.7
3.0
3.3
4.3
5.3
3.0
3.0
3.6
3.8
3.6
5.3
1.7
1.4
0.26
2.96
3,38
3.74
2.71
0.08
1.5
1.75
3.26
4.09
5.1
D035-1
0020-1
0.06
PPT in.
2.26
0.55
0.82
PPT cm
0.7
2.51
Nov
Oct
0.15
5.74
1.40
2.08
Dec
1.78
6.38
0.66
Jan
7.52
8.59
9.50
6.88
3
2
3
2
3
2
3
1
1
1
99.0
81.3
35.0
17.8
101.5
84.5
41.5
19.0
1.27
6.5
Feb
0.20
3.81
4.45
8.28
10.39
3.23
16.51
2
2
3
2
3
2
3
2
3
2
2
3
2
1
1
1
1
1
1
1
1
50.0
78.0
65.0
28
54
41.5
33.5
Saturation (graphing)
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
1
47.0
23.3
101.0
81.0
43.0
21.0
93.0
72.0
36.0
13.0
81.0
60.0
15.0
41.0
67.0
55.0
47.0
40.0
66.0
53.0
46.0
28.0
53.0
40.5
33.0
31.5
57.5
45.0
37.0
Site F
WITHAM HILL DATA
Benton County
2/17/96
2/23/96
3/01/96
3/08/96
3/15/96
3/23/96
3/30/96
4/04/96
4/11/96
4/18/96
4/25/96
5/04/96
5/09/96
5/16/96
5/24/96
5/30/96
-8.5
-8.0
-4.0
-8.0
-4.5
-3.0
-2.0
-3.5
-25.5
-27.0
-24.5
-14.5
-15.0
-12.5
-15.0
-30.5
-33.5
-31.0
-31.5
-33.5
-30.0
-40.0
-42.0
-34.0
-34.0
-32.0
-54.0
-58.0
-7.5
-8.0
-5.5
-8.5
-8.5
-11.0
-7.5
-10.0
-51.5
-55.0
-65.5
-70.0
-21.5
-23.0
-21.0
-15.5
-17.5
-15.0
-18.0
-49.0
-53.5
DO-W100
D075-1
D035-1
D020-1
3.3
2.5
2.0
2.4
2.5
3.3
2.7
4.5
2.1
2.0
2.7
1.9
1.8
2.8
5.1
2.0
4.2
1.9
2.3
1.9
1.7
1.8
2.9
PPT in.
0.04
0.55
March
11.38
1.40
1.73
0.43
0.2
0.06
0.17
1.63
2,04
0.11
6/14/96
6/21/96
0
0.1
Field Data
W-100
P-75-1
P-35-1
P-20-1
PPT cm
0.10
4.48
0.7
2.0
2.5
3.1
2.2
1.7
1.9
1.6
0.98
0.78
0.72
2.9
April
4.39
1.09
0.51
1.78
May
2.49
1.98
1.83
7.37
3
2
3
1
1
31
32
58
45.5
38.5
61
June
0.15
0.43
4.14
5.18
0.28
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
3
3
2
2
2
3
2
2
2
1
1
1
1
1
1
32.0
58.0
44.0
38.0
28.0
53.0
42.0
33.5
49.0
77.0
64.5
38.0
65.0
52.5
45.0
54.0
83.5
71.0
55.0
83.5
70.0
2
1
63.5
92
1
57.5
84
72
1
77.5
108
3
2
47.5
40
1
75
105
2
2
1
1
1
89
120
45
73
61
39
67.5
55
48
1
72.5
103.5
0.25
Site F
WITHAM HILL DATA
6/28/96
Benton County
9/24/96 10/03/96 10/10/96 10/17/96 10/24/96 10131/96 11/07/96 11/17/96 11/21/96 11/27/96 12/05/96 12/10/96 12/19/96 12/24/96 12/31/96
1/11/97
1/20/97
-4.5
-4.0
-1.5
-3.5
-24.5
-27.5
-24,0
-7.5
-11.5
-7.0
-8.0
3.6
2.7
2.7
3.0
1.8
1.0
1.5
2.8
0.52
2.25
Field Data
W-100
-90.0
-5.0
-6.0
-3.0
-6.0
-10.5
-12.5
-9.5
-19.5
-5.5
-6.5
-3.5
-5.0
-5.5
-6.5
-3.0
-5.0
-25.5
-29.0
-26.0
8.5
8.5
8.6
7.7
8.7
4.5
2.5
5.8
1.4
2.0
3.2
5.0
1.4
2.4
4.6
4.0
6.58
2.46
3.08
5.02
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
D035-1
D020-1
PPT in.
0.75
0
0.39
1.37
2.17
1.91
0.99
3.48
0.57
2.4
4.3
Nov
Oct
PPT cm
0.45
1.39
8.1
5.51
3.53
-6.5
-7.5
-5.0
-6.5
5.3
1.7
1.4
2.1
0.69
4.43
6.8
Dec
1.14
1.45
Jan
16.71
6.25
7.82
12.75
1.75
11.25
17.27
1.32
5.72
3
3
2
2
3
2
3
2
2
3
2
3
2
2
3
2
1
1
1
1
1
1
1
1
1
Saturation (gs
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
113.5
28.5
56
43
36
34
29
62.5
49.5
49.5
56.5
43.5
35
29
56.5
43
35
49
79
66
30
57.5
45
36.5
28
54
41.5
33.5
48
77.5
64
31
61.5
47
38
Site F
WITHAM HILL DATA
Benton County
1/25/97
2/01/97
2/08/97
2/15/97
2/22/97
3/01/97
3/08/97
3/15/97
3/22/97
3/30/97
4/05/97
4/12/97
4/18/97
4/26/97
5/03/97
5/10/97
5/16/97
-7.0
-7.5
-6.0
-4.5
-12.5
-15.5
-13.0
-13.0
-19.0
-20.5
-18.5
-22.0
-24.5
-22.5
-22.5
-25.0
-23.0
-3.5
-3.0
-2.0
-2.5
-7.5
-6.0
-3.0
-4.0
-11.0
-11.0
-9.5
-9.0
-21.0
-24.0
-20.0
-25.0
-29.0
-25.0
-34.0
-37.5
-33.5
-36.5
-41.0
-32.5
-37.0
-34.0
-30.5
-34.0
-31.0
-28.5
-32.0
-28.0
-52.5
-58.5
-79.0
2.5
1.4
1.6
3.4
2.0
2.8
1.4
2:8
1.0
1.9
1.4
3.0
1.2
1.7
2.6
2.6
1.7
2.2
2.8
1.6
1.9
2.5
2.6
5.7
1.7
3.8
2.8
2.0
4.0
1.3
3.3
1.2
2.1
2.4
0.9
1.5
2.6
2.3
2.0
2.8
1.6
1.9
3.1
1.6
D020-1
3.0
1.5
0.7
2.4
PPT in.
0.8
3.31
0.41
0.75
2.11
1.22
0.23
0.68
1.88
8.41
1.04
1.91
6.22
5.36
3.10
0.58
0.45
April
1.14
0.35
2.03
0.35
Mar
0.89
2.45
PPT cm
0.24
Feb
0.61
0.89
1.73
4.78
0.68
May
1.73
3
2
3
3
3
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
46
75
63
27
53
42
32.5
31
34.5
56
61
91
43
49.5
39
57.5
87.5
73.5
5/24/97
Field Data
W-100
P-75-1
P-35-1
P-20-1
DO-W100
D075-1
0035-1
5.1
1.9
2.9
0.11
0
0.28
0.94
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
30.5
57.5
46
34.5
3
36
65.5
53
43
42.5
70.5
58.5
45.5
74.5
62.5
34
44.5
74
60
48.5
79
65
60
56
87
74
54
84
71
52
82
68
1
76
108.5
0.37
102.5
WITHAM HILL DATA
6/01/97
6/07/97
Field Data
W-100
-64.5
P-75-1
P-35-1
P-20-1
D0 -W100
5.8
0075-1
D035-1
0020-1
PPT in.
PPT cm
1.58
June
1.09
4.01
2.77
Saturation (gi
20 cm
35 cm
75 cm
Raw PZ Data
W-100
P-75-1
P-35-1
P-20-1
88
Site F
Benton County
307
Appendix D
Vegetation Characterization Data
Vegetation Characterization of Site l
SPECIES
AGST
AGTE
ALPR
AREL
BRCO
BRHY
BRCO
BRMO
CADE
CALE
CAOL
CATU
CAUN
CEVI
CIVU
DACA
SCIENTIFIC NAME
Agrostis stolonifera L.
Agrostis tenuis Sibth.
Alopecurus pratensis L
Arrhenatherum elatus (L.) J. & K. Presl
Brodiaea coronaria (Salisb.] Engl.
Brodiaea hyacinthina (Lindl.) Baker
1.3
1.4
Plot Number 1.1
1.2
1.5
Mean %
Quadrat 4/0 C
0/3 B
0/ 1
A
4/ 1
D
5/ 1 E
areal
Date 5/15 6/06 Avg. 5/15 6/06 Avg. 5/15 6/06 Avg. 5/15 6/06 Avg. 5/15 6/06 Avg.
cover
COMMON NAME
Creeping Bentgrass
Colonial Bentgrass
10
15
12.5
20
40
30.0
15
20
17.5
25
30
27.5
30
80
70
75.0
18
40
29.0
45
50
47.5
35
35
35.0
42
1
1
1
1
1.0
1.0
1
1.0
35 32.5
24.0
53.5
48.0
Meadow Foxtail
Tall Oatgrass
Hairy Chess
Soft Brome
Dense Sedge
Carex densa (L.H. Bailey) L.H. Bailey
Hare's-foot Sedge
Carex leporina L.
Few-seed Bitter-cress
Cardamine oligosperma Nutt.
Foothill Sedge
Carex tumulicola Mackenzie
One-sided Sedge
Carex unilateralis Mackenzie
Chickweed
1
Cerastium viscosum L.
Bull Thistle
Cirsium vulgare (Savi) Ten.
Queen Anne's Lace
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Schultes Common Spikerush
ELPA
Epilobium glandulosum Lehm.
EPGL
Festuca dertonensis (All.) (F. bromoides)
FEDE
Meadow Fescue
FEPR
Festuca pratensis Huds.
Red Fescue
FERU
Festuca rubra L.
Tall Fescue
Festuca arundinacea Schreb.
FEAR
Catchweed Bedstraw
1
Galium aparine L.
GAAP
Geranium
Geranium dissectum L.
GEDI
Velvet Grass
HOLA
Holcus lanatus L.
Soft Rush
JUEF
Juncus effusus L.
Slender Rush
Juncus tenuis Willd.
JUTE
Birds-foot Trefoil
Lotus corniculatus L.
LOCO
Fountain Miner's-Lettuc
MOFO
Montia fontana L.
Montia linearis (Dougl.] Greene
MOLI
1
Blue Forget-Me-Not
MYDI
Myosotis discolor Pers.
Yellow Parentucellia
Parentucellia viscosa (L.) Caruel
PAVI
20
Kentucky Bluegrass
Poa pratensis L.
POPR
Straight-beak Butter-cu
Ranunculus orthorhynchus Hook.
RAOR
Sheep Sorrel
Rumex acetosella L.
RUAC
Suckling Clover
TRDU
Trifolium dubium Sibth.
Clover
Trifolium Trifolium spp.
Corn Speedwell
Veronica arvensis L.
VEAR
Common Vetch
VISA
Vicia sativa L.
Bromus commutatus Schrad.
Bromus mollis Schrad.
1
1.0
1
_,
65
0.2
0.2
1
1
1.0
0.6
0.4
15.0
15.0
1.5
2.2
0.6
1.0
1.0
1
1
20
25
10
3
6.5
1
1
1.0
1
1
-,
3
1
10
2.0
1.0
15.0
25
15
1
1
1
1
1
1
25
10
1
1
2
2
20.0
20
15
1.0
1.0
1
I
1.0
1.0
1
1
1.0
35
20
1.0
1
1
1.0
2.0
1
1
1.0
17.5
17.5
27.5
22.5
15
15
1
2
0.6
30
5
17.5
35
5
20.0
19.5
1
1
1.0
0.6
0.6
Ve:etation Characterization of Site2
Plot Number 2.1
2.2
I uadrat
EN 1
Date
SPECIES
AGST
AGTE
ALPR
AREL
BRCO
BRHY
BRCO
BRMO
CADE
CALE
CAOL
CATU
CAUN
CEVI
C1VU
DACA
ELPA
EPGL
FEDE
FEPR
FERU
FEAR
GAAP
GEDI
HOLA
JUEF
JUTE
LOCO
MOFO
MOLI
MYDI
PAVI
POPR
RAOR
RUAC
TRDU
Cree in Bent:rass
Colonial Bent:rass
Alo.ecurus .ratensis L
Arrhenatherum elatus L. J. & K. Presl
Brodiaea coronaria Salisb. En:l.
Brodiaea h acinthina Lindl. Baker
Bromus commutatus Schrad.
Bromus mollis Schrad.
Carex densa L.H. Baffle
Carex le .orina L.
L.H. Baffle
Cardamine olios.erma Nutt.
Carex tumulicola Mackenzie
Carex unilateralis Mackenzie
Cerastium viscosum L.
Cirsium vul:are Savi Ten.
Daucus carota L.
Eleocharis .alustris L. Roem. & J.A. Schultes
E.ilobium Ilandulosum Lehm.
Festuca dertonensis All. F. bromoides
Festuca ratensis Huds.
Festuca rubra L.
Festuca arundinacea Schreb.
Galium a.arine L.
Geranium dissectum L.
Holcus lanatus L.
Juncus effusus L.
Juncus tenuis Willd.
Lotus corniculatus L.
Montia fontana L.
MIMI 6 06
MI
WI B
IMMO
2.5
C
6 06
areal
E
6 06 12111 cover
40
25
32.5
25
30
10
10
10.0
2
2
27.5
2.0
40
50
2
3
45.0
2.5
1
1
1.0
25
20
2
2
22.5
2.0
20
2
50 35.0
2
2.0
32.5
3.7
Meadow Foxtail
Tall Oat:rass
Chess
Soft Brome
Hai
0.2
Dense Sed:e
Hare's-foot Sed:e
Few-seed Bitter-cress
Foothill Sed:e
One-sided Sed:e
Chickweed
Bull Thistle
1
1
1.0
0.2
ueen Anne's Lace
Common S.ikerush
Meadow Fescue
Red Fescue
Tall Fescue
Catchweed Bedstraw
Geranium
Velvet Grass
Soft Rush
Slender Rush
Birds-foot Trefoil
Fountain Miner's-Lettuce
Montia linearis Dou:I. Greene
M osotis discolor Pers.
Parentucellia viscosa L. Caruel
Poa ratensis L.
Ranunculus orthorh nchus Hook.
Yellow Parentucellia
Rumex acetosella L.
Trifolium dubium Sibth.
Shee. Sorrel
Sucklin: Clover
Trifolium Trifolium s...
Veronica arvensis L.
VEAR
VISA
Vicia sativa L.
ME 6 06
El
En= rffilltini 6 06 MIMI
2.4
2.3
D
COMMON NAME
SCIENTIFIC NAME
A rostis stolonifera L.
A:rostis tenuis Sibth.
MI A
Blue For:et -Me -Not
Kentuck Blue rass
Strai ht-beak Butter-cu
5
8
6.5
14
36
29
25.0
20.0
11
39
31
40
30
3
3
39.5
30.5
3.0
1
1
1.0
3
3
3.0
3
3
3.0
19
16
2
25
20
22.0
44
36
44
36
2
8
44.0
36.0
5.0
5
18.0
3.5
2.5
47
38
33
27
1
5
40.0
32.5
3.0
34.1
27.4
2.9
0.2
2
3
2.5
1
1
1.0
1
1
1.0
10
4
7.0
5
5
5.0
8
1
4.5
1
1
1.0
1
1
1.0
1
1
2
3
2.5
5
5
5.0
2
1
1.0
1.1
5
3.5
5.0
0.4
Clover
Corn S.eedwell
Common Vetch
1
1
1.0
1
5
3.0
2
1
1.5
1.6
Ve:etation Characterization of Site 3
Plot Number 3.1
uadrat
4
1
3.2
D
Date 5 15 6 06
SPECIES
AGST
AGTE
ALPR
AREL
BRCO
BRHY
BRCO
BRMO
CADE
X
1
3.5
Mean %
areal
A
Av:
cover
COMMON NAME
SCIENTIFIC NAME
A rostis stolonifera L.
A. rostis tenuis Sibth.
Cree.in: Bent:rass
35
45
Colonial Bent:rass
2
2
40.0
2.0
Alo.ecu us . a ensis L
Arrhenatherum elatus L. J. & K. Presl
Brodiaea coronar a Salisb. En:!.
Brodiaea h acinthina Lindl. Baker
Meadow Foxtail
Tall Oa ass
2
1
1.5
1
1
1.0
Chess
Soft Brome
Dense Sed:e
Hare's-foot Sed:e
Carex le .orma L.
CALE
Few-seed Bitter-cress
Cardamine or:os. rma Nutt.
CAOL
Foothill Sed:e
Carex tumulicola Mackenzie
CATU
One -sided Sed:e
Carex unilateralis Mackenzie
CAUN
Chickweed
Cerastium v scosum L.
CEVI
Bull Thistle
Cirsium vulgare (Savi) Ten.
CIVU
Queen Anne's Lace
DACA
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Schu Common Spikerush
ELPA
EPGL
Epilobium glandulosum Lehm.
Festuca dertonensis (All.) (F. bromoides)
FEDE
Meadow Fescue
Festuca pratensis Huds.
FEPR
Red Fescue
FERU
Festuca rubra L.
Tall Fescue
FEAR
Festuca arundinacea Schreb.
Catchweed Bedstraw
Galium aparine L.
GAAP
Geranium
Geranium dissectum L.
GEDI
Velvet Grass
HOLA
Holcus lanatus L.
Soft Rush
JUEF
Juncus effusus L.
Slender Rush
Juncus tenuis Willd.
JUTE
Birds-foot Trefoil
Lotus corniculatus L.
LOCO
Fountain Miner's-Lettuce
MOFO
Montia fontana L.
Montia linearis (Doug!.) Greene
MOLI
Blue Forget-Me-Not
Myosotis discolor Pers.
MYDI
Yellow Parentucellia
Parentucellia viscosa (L.) Caruel
PAVI
Kentucky Bluegrass
Poa pratensis L.
POPR
Straight-beak Butter-cup
Ranunculus orthorhynchus Hook.
RAOR
Sheep Sorrel
Rumex acetosella L.
RUAC
Suckling Clover
Trifolium dubium Sibth.
TRDU
Clover
Trifolium Trifolium spp.
Corn Speedwell
Veronica arvensis L.
YEAR
Common Vetch
VISA
Vicia sativa L.
Bromus commutatus Schrad.
Bromus mollis Schrad.
Carex densa L.H. Baile L.H. Baile
3.4
3.3
44 E
20 B
2 1
C
5 15 6 06 Av:. 5 15 6 06 Av:. 5 15 6 06 Av:. 5 15 6 06
1
Hai
10
7
40
3
25.0
5.0
45
15
30
20
20
30
25.0
60
50
5
5
5.0
5
5
55.0
5.0
1
1
1.0
5
5
5.0
12.5
1
39
16
1
1
1
1.0
2
8
5.0
1
1
1
21
9
14
6
17.5
7
7.5
3
21
9
1
1
1.0
1
1
10
10.0
18
30
1
1
2
1
2.0
1.0
3
1
2.0
2
1
1.5
1
1
1.0
1
1
5
15
2
1
0.3
0.4
0.2
1.0
35
42.0
11
20
15.5
28.0
15
5
2
8
6.5
11.9
1
18.0
1.0
1
1.5
1
1
1.0
0.9'
0.4
10
10
10.0
9.8
14.0 49
6.0 21
1.0
1
24.0
I
2
0.4
4.5
1.0
1.5
1.0
51.0
21.5
36.0
2.4
0.3
0.2
5.0
25.0
2
63
27
10
35.0
1.0
1
1
25
1.0
1
1
1.0
15
10
1
1
12.5
1.0
1.4
2.0
10.0
1.5
2.5
1
1
1.0
4
2
3.0)
1.4
0.4
Vegetation Characterization of Site 4
Plot Number 4.1
4.2
4.4
4.3
A
3/2 C
5/3 D
Quadrat 0/1
Date 5)15 6/06 Avg. 5/15 6/06 Avg. 5/15 6/06
SPECIES
AGST
AGTE
ALPR
AREL
BRCO
BRHY
BRCO
BRMO
CADE
CALE
CAOL
CATU
CAUN
CEVI
CIVU
DACA
ELPA
EPGL
SCIENTIFIC NAME
Agrostis stolonifera L.
Agrostis tenuis Sibth.
Alopecurus pratensis L
Arrhenatherum elatus (L.) J. & K. Presl
Brodiaea coronaria (Salisb.) Engl.
Brodiaea hyacinthina (Lindl.) Baker
Avg.
Mean %
3/0 B
5/15 6/06
Avg.
10
5.5
10.9
35.0
30.5
areal
cover
COMMON NAME
Creeping_Bentgrass
Colonial Bentgrass
Meadow Foxtail
Tall Oatgrass
Hairy Chess
Soft Brome
Dense Sedge
Carex densa (L.H. Bailey) L.H. Bailey
Hare's-foot Sedge
Carex leporina L.
Few-seed Bitter-cress
Cardamine ol gosperma Nutt.
Foothill Sedge
Carex tumulicola Mackenzie
One-sided Sedge
Carex unilateralis Mackenzie
Chickweed
Cerastium viscosum L.
Bull Thistle
Cirsium vulgare (Savi) Ten.
Queen Anne's Lace
Daucus carota L.
Eleocharis palustris (L.) Roem. & J.A. Scht Common Spikerush
Epilobium glandulosum Lehm.
Festuca dertonensis (All.) (F. bromoides)
FEDE
Meadow Fescue
Festuca pratensis Buds.
FEPR
Red Fescue
Festuca rubra L.
FERU
Tall Fescue
FEAR
Festuca arundinacea Schreb.
Catchweed Bedstraw
Galium aparine L.
GAAP
Geranium
Geranium dissectum L.
GEDI
Velvet Grass
HOLA
Holcus lanatus L.
Soft Rush
JUEF
Juncus effusus L.
Slender Rush
Juncus tenuis Willd.
JUTE
Birds-foot Trefoil
Lotus corniculatus L.
LOCO
Fountain Miner's-Lettui
Montia fontana L.
MOFO
Montia linearis (Dougl.) Greene
MOLI
Blue Forget-Me-Not
MYDI
Myosotis discolor Pers.
Yellow Parentucellia
Parentucellia viscosa (L.) Caruel
PAVI
Kentucky Bluegrass
Poa pratensis L.
POPR
Straight-beak Butter-cu
RAOR
Ranunculus orthorhynchus Hook.
Sheep Sorrel
Rumex acetosella L.
RUAC
Suckling_ Clover
Trifolium dubium Sibth.
TRDU
Clover
Trifolium Trifolium spp.
Corn Speedwell
Veronica arvensis L.
VEAR
Common Vetch
Vicia saliva L.
VISA
Bromus commutatus Schrad.
Bromus mollis Schrad.
Avg,,
4.5
5/4
E
5/15 6/06
5
30
17.5
10
20
15.0
18
15
16.5
40
25
32.5 50
15
32.5
40
25
32.5 40
15
17.5
25
18
21.5
20
20
20.0
10
8
9.0
3
3
3.0
10
20
10
10
10.0
15.0
7
5
7
5
7.0
5.0
3
3
3.0
18
20
19.0
3
3
3.0
1
1
1.0
12
3
12
3
12.0
3.0
5
5
4
5.0
4.0
2
2
2.0
4
1
1
1.0
5
10
7.5
15
10
10
5
12.5
5
15
10
15
75
80
60
80
3
3
7.5
77.5
3.0
20
3
3
3.0
2
2
2.0
15.0
15
15
15.0
70.0
50
75
62.5
1
30
15
20
17.5
13.7
5
5
5
5
5.0
5.0
4.4
5.0
10
5
7.5
7.1
0.2
5
5
5.0
1
1
1.0
4.8
2.2
7.5
3.0
8.5
1.5
65
80
3
2
3
2
5
5
72.5
3.0
2.0
5.0
68
85 76.5
2
3
3
3.0
3
3
3.0
15
2
15
2.0
71.8
0.6
0.8
15.0
5.8
1
312
Appendix E
Mineralogy Laboratory Procedures
313
MINERALOGICAL ANALYSIS
A. Procedure for bulk random powder mounts
1.
Preparation of the sample. A small soil sample was ground into powder in
a mortal and pestle.
2. Slide preparation. The powder was gently tampered into a bulk slide
holder and pressed to create a flat surface.
B. Procedure for film slide mounts
1.
Preparation of the samples. The air-dried samples were gently crushed
with a rolling pin and a mortal and pestle. Crushed material was placed
in 1-liter beakers. No pretreatments were done to remove organic matter
or Fe-Al.
2. Dispersion of the samples. Samples were dispersed in 500-m1 distilled
water with 5 ml of NaHMP (sodium hexametaphosphate) and shaken
overnight.
3. Separation of the fractions. The samples were removed from the shaker
and allowed to settle for 5 minutes to remove the sand and coarse silt.
Subsamples of the decanted suspended materials were used for the <15
gm fraction. The main samples of the suspended materials were
centrifuged at 650 rpm for 6 minutes and the decanted supernatant used
for the < 2 gm fraction. The <15 f1111 was concentrated by squirting 5 ml
of 1N MgC12 into the suspended materials, centrifuged at 5,000 rpm for 5
minutes, and pouring off the clear liquid.
4. Sample treatments. Both the < 2 fiM and < 15 gm fractions were Mg+2-
saturated by washing three times with 20-30 ml of 1N MgC12 followed by
three washings with distilled water.
5. Slide preparation. Oriented film slides were prepared by taking a small
amount of sediment from the centrifuge tube with a microspatula and
smearing it on a glass slide until a thin smooth surface was obtained for
both the <2 fiM fraction and <15 p.m fraction.
6. Further sample treatments. After the slides were made from the <2 p.m
Mg+2-saturated samples, the remaining < 2 gm separates were then K +saturated by washing three times with 20-30 ml of 1N KC1 followed by
three washings with distilled water. Slides were prepared for analysis the
same as in Step A.5 above.
7. Slide treatments. The Mg+2 saturated slides were prepared for XRD
analysis using three treatments. The Mg+2 54% relative humidity slides
were prepared by placing the Mg+2 saturated slides in a hydrator for 1224 hours. Once the XRD was run, the MgE2-glycol slides were made by
lying the Mg+2-saturated slides in a ethylene glycol hydrator, heating 2-3
hours in a 650C oven, and letting them equilibrate for 12-24 hours.
314
Mineralogical Analysis, Continued
Following the XRD on glycolated slides, the slides were set aside to allow
the glycol to evaporate. Then the Mg+2-glycerol slides were made by lying
the slides in a glycerol hydrator, heating 3 hours in a 1100C oven, and
allowing them to equilibrate for 24 hours. The K +- saturated slides were
prepared with two treatments. K+ 54% relative humidity slides were run
after they were equilibrated for 12-24 hours. Once the XRD was run, the
slides were placed in an oven at 1100C for 2 hours and analyzed
immediately while hot.