SOIL
SCIENCE
SOCIETY
OF
NORTH
CAROLINA
Summary of
Forty-sixth Annual Meeting
Vol. XLVI Proceedings
2003
PROCEEDINGS OF THE
FORTY-SIXTH ANNUAL MEETING
OF THE
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
McKIMMON CENTER
RALEIGH, NORTH CAROLINA
JANUARY 14–15, 2003
EDITED BY
Catherine E. Stokes
OFFICERS FOR 2003–2004
President
Aziz Amoozegar
President-Elect
Steve Stadelman
Secretary
Steve Dillon
Treasurer
Roberta Miller-Haraway
Other Executive Committee Members
Joe Kleiss, Divisional Chair – Academics & Research
Elwood Black, Divisional Chair – Business, Industry & Consultants
Steve Bristow, Divisional Chair – Public Health
Richard Hayes, Divisional Chair – Government Agencies
http://agronomy.agr.state.nc.us/sssnc/index.htm
TABLE OF CONTENTS
CORRESPONDING AUTHORS OF PAPERS ....................................................................................................... 8
2003 ACHIEVEMENT AWARD RECIPIENT ......................................................................................................... 11
PRESENTATIONS
PLAT and NLEW: Agricultural Tools for Management and Regulation
D.L. Osmond .................................................................................................................................................. 13
Response of Cotton to Soil P and K Gradients in Long-term Fertility Plots
C.R. Crozier, F.R. Walls, D.H. Hardy, R.D. Coltrain, J.S. Barnes, and J.W. Smith ....................................... 16
Comparison of Bucket-wheel Spoil and Phosphogypsum/Clay Blend as Substrates for Nonriverine
Wet Hardwood Forest Restoration
R.L. Andrews and S.W. Broome .................................................................................................................... 25
Nutrient Application Uniformity with Wastewater Irrigation Systems
K.A. Shaffer and G.F. Aldridge ....................................................................................................................... 26
Effective Sodium Management for Industrial Waste Land Application
S.A. Stadelman .............................................................................................................................................. 31
Phosphorus Leaching in Acid Sandy Soils Following Long-term Waste Applications
N.O. Nelson and R.L. Mikkelsen .................................................................................................................... 35
Application of Soil Water Budgets to Landscape Hydrology Analysis
G.S. Kreiser, M.J. Vepraskas, and R.L. Hoffman ........................................................................................... 42
Modeling Construction Site Impacts on Watersheds
A.D. Moore, R.A. McLaughlin, and H. Mitasova ............................................................................................ 49
Field Assessment of Water Flow from Trenches of Septic Systems
A. Amoozegar, C.P. Niewoehner, and D. Lindbo ............................................................................................ 54
Potential Nitrogen Contribution from Septic Systems to North Carolina’s River Basins
S. Pradhan, M.T. Hoover, R. Austin, and H.A. Devine ................................................................................... 62
Analysis of Tire Chips as a Substitute for Stone Aggregate in Nitrification Trenches of On-site
Septic Systems: Status and Notes on the Comparative Macrobiology of Tire Chip vs. Stone
Aggregate Trenches
B.H. Grimes, S. Steinbeck, and A. Amoozegar .............................................................................................. 72
The Role of Soil Scientists in On-site System Permitting
M.S. Heath, Jr. ............................................................................................................................................... 77
PROCEEDINGS OF THE FORTY-SIXTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
POSTERS
Subsurface Movement of Phosphorus
J.A. Lee and D.L. Osmond ............................................................................................................................ 80
Phosphate Adsorption on Hematite
N. Khare, S.L. Wang, and D.L. Hesterberg .................................................................................................... 80
Degree of Phosphorus Saturation of Selected Soils of North Carolina
A.M. Johnson and D.L. Osmond .................................................................................................................... 80
Method for Continuous Collection of Soil Solution for Phosphate Analysis
N.O. Nelson and R.L. Mikkelsen .................................................................................................................... 81
Phosphorus Accumulation in North Carolina Piedmont Soils Receiving Animal Waste Applications
T.K. Yarborough, R.L. Mikkelsen, and J.M. Stucky ........................................................................................ 81
Determing the Effectiveness of a Naturally Revegetating Riparian Buffer
T.A. Smith, D.L. Osmond, J.W. Gilliam, C.E. Moorman, J.W. Stucky ........................................................... 82
Effectiveness of Shrub Buffers on Nitrate-N Removal
C.C. Wafer and D.L. Osmond ........................................................................................................................ 82
Evaluation of the Realistic Yield Expectations of Soil Map Units in the North Carolina Coastal Plain
M.M. Lohman, J.G. White, and D.L. Osmond ................................................................................................ 82
Nitrogen Rates and Realistic Yield Expectations for Cotton in Northeastern North Carolina
W.T. Nixon, F.R. Walls, J.K. Messick, C.C. Crozier, R.C. Reich, and P. Boone ............................................ 83
Using 15N Labeled Swine Effluent to Determine Nitrogen Use in Soybean
M.B. Allen and R.L. Mikkelsen ....................................................................................................................... 83
Using Remote Sensing for In-season Nitrogen Application Decisions for Corn in North Carolina
R.P. Sripada, R.W. Heiniger, J.G. White, C.R. Crozier, R.Weisz, and J.M. Burleson .................................... 84
[Aerial Color Infrared Photography for In-season Nitrogen Application Decisions for Corn in the Southeast]
Effect of Small Grain Cover on No-till Pumpkin Production
L.F. Overstreet and G.D. Hoyt ....................................................................................................................... 84
Stratigraphy of a North Carolina Bay Using Ground-penetrating Radar
R.P. Szuch, J.G. White, M.J. Vepraskas, J.A. Doolittle, C.W. Zanner, and L. Paugh .................................... 84
Agriculture Impacts on Soils of a Drained Carolina Bay
J.M. Ewing and M.J. Vepraskas ..................................................................................................................... 85
Spatial Patterns of Soil Carbon in Forest Soils of the Lower Coastal Plain of North Carolina
E.S. Anderson, J.A. Thompson, and R.K. Kolka ............................................................................................ 85
Updating WATERSHEDSS: a Web-based Decision Support System for Best Management Practices
Selection
S.A. Hayes and D.L. Osmond ........................................................................................................................ 86
A Nutrient Management Decision Support System for the Tropics: NuMaSS
D.L. Osmond, T.J. Smyth, R.S. Yost, D.L. Hoag, W.S. Reid, W. Branch, X. Wang, and H. Li ...................... 86
PROCEEDINGS OF THE FORTY-SIXTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
Review of Farmers’ Attitudes and Experiences in the Process of Adoption of Best Management Practices
as Currently Proposed for Critical North Carolina Watersheds
Interagency Committee of NCDA&CS, NCDENR–Division of Soil and Water, NCSU, and USDA-NRCS .... 86
SOIL SCIENCE SOCIETY OF NORTH CAROLINA BUSINESS
MINUTES ....................................................................................................................................................... 88
AUDIT REPORT ............................................................................................................................................ 91
2003 COMMITTEES ...................................................................................................................................... 92
HISTORICAL PERSPECTIVES — PAST ACHIEVEMENT AWARDS ........................................................... 93
DUES-PAYING MEMBERS ........................................................................................................................... 94
PAST EXECUTIVE COMMITTEE MEMBERS .............................................................................................. 96
CONSTITUTION AND BYLAWS ................................................................................................................... 98
PROCEEDINGS OF THE FORTY-SIXTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
8
CORRESPONDING AUTHORS OF PAPERS
Mark Benjamin Allen, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Nidhi Khare, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Dr. Aziz Amoozegar, Professor
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Gary S. Kreiser, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Eric Scott Anderson, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
J.A. Lee, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Ross L. Andrews, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Mindy Lohman, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Dr. Carl R. Crozier, Extension Specialist
Vernon James Center
207 Research Station Road
Plymouth, NC 27962
Amber Moore, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Justin M. Ewing, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Nathan O. Nelson, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Barbara Hartley Grimes
NonPoint Source Pollution Program Coordinator
NCDENR Division of Environmental Health
1642 Mail Service Center
Raleigh, NC27699-1642
Wayne T. Nixon, Regional Agronomist
NCDA&CS Agronomic Division
286 Bagley Swamp Road
Hertford, NC 27944
Sara A. Hayes, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Milton S. Heath, Jr., Assistant Director
Institute of Government
University of North Carolina
Chapel Hill, NC 27599-3330
Amy M. Johnson, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Deanna L. Osmond, Assistant Professor
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Laura F. Overstreet, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Sushama Pradhan, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
9
Karl A. Shaffer, Extension Associate
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Ryan Paul Szuch, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Timothy A. Smith, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Carrie Wafer, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
Ravi P. Sripada, Graduate Student
Department of Soil Science
NCSU Box 7619
Raleigh, NC 27695-7619
T. Kent Yarborough, Agronomist
NCDA&CS Agronomic Division
4300 Reedy Creek Road
Raleigh, NC 27607-6465
Steve A. Stadelman
Novozymes North America, Inc.
77 Perry Chapel Church Rd.
Franklinton, NC 27525
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
10
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
11
Dr. George C. Naderman
2003 Achievement Award Recipient
The annual SSSNC Achievement Award is
given to an individual to acknowledge and
commend his/her outstanding achievements in the
field of soil science. The criteria used in evaluating
these achievement include research, teaching,
extension, administration, and/or other areas that
are directly related to soil science.
The individual selected to receive the 2003
Achievement Award is Dr. George C. Naderman.
Dr. Naderman is a native of Indiana. He has
indeed made a number of very significant
contributions in research, extension, and
teaching — all designed to benefit North Carolina
farmers.
Education
Dr. Naderman received his B.S. degree in
Agronomy (1962) and M.S. degree in Soil
Science (1969) from Purdue University. He then
received a Ph.D. in Agronomy (1973) from
Cornell University.
Professional Experience
1972–1974: Research Associate (Cornell
University) with the Tropical Soil Project in Brazil
1974–1980: Assistant Professor and Extension
Specialist in soil management (NCSU Soil Science
department)
July 1983 – December 1984: Extension
Program Leader for the NCSU-AID project in Peru
1980–2000: Associate Professor and Extension
Specialist in soil management (NCSU Soil Science
department)
Honors and Awards
1980: Honorary State FFA Degree
1990: Professional Service Award (Water
Quality) from the N.C. chapter of the Soil and Water
Conservation Society
1994: Soil Conservationist of the Year (awarded
by the N.C. Wildlife Federation)
Narrative
During his tenure as Extension Specialist, Dr.
Naderman made significant contributions to N.C.
farmers on the importance and need for using
proper tillage practices. He demonstrated this need
through on-farm research experiments and
statewide extension educational programs. Dr.
Naderman’s entire career focused on providing
tillage management information that was relevant
for a variety of soils across the major geographic
regions.
In reality, Dr. Naderman has changed the way
many growers conduct their soil management
business. In his even-tempered, low-key, baritone
voice, he earned the respect of N.C. growers and
has been successful in selling them on more
appropriate and more effective tillage practices.
Over the years, we all have become
accustomed to hearing tillage options such as
ripper-bedder-spider and spider-ripper-beddersmoother (12-foot railroad cross-tie). Since all our
soils need lime (based on soil test), I would like to
propose one other tillage option: cutter-ripperspreader-bedder-spider-smoother-planter. Terms like
ridge-till, no-till, and minimum tillage integrated with
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
12
nutrient and soil management concepts have
become common language across the farming
community.
One becomes aware rather quickly that the
“Pope of Tillage” has been extremely diligent in
spreading his knowledge and experience on the
latest tillage and land management practices.
Growers proclaim enthusiastically, “This is what Dr.
Naderman told me to do!” His influence on farmers
is evident, and other farmers continue to take
notice.
Being a good communicator with an evangelical
delivery is truly an asset when farmers are being
introduced to new concepts. Convincing people to
break with tradition is not an easy task to achieve.
However, Dr. Naderman used his unique talent in
charting a new course for farmers to follow . . . and
follow they did.
Dr. Naderman has written numerous articles on
tillage topics and authored several chapters in books
and other farmer-friendly publications, including the
production guide (“Bible”) for cotton and corn. He
authored a handbook entitled High School Land
Judging in North Carolina, which has become the
standard guide for land judging. His efforts have
been directed at educating future farmers and
helping the established farming community to
become more efficient and more environmentally
friendly.
Another of Dr. Naderman’s major contributions
has been his willingness to share technical
information with county Extension agents through
on-farm demonstrations and numerous training
sessions with agents and growers. George has
always been ready and willing to go into the field
and share his knowledge with farmers.
On behalf of the members and leadership of the
N.C. Soil Science Society, we congratulate Dr.
Naderman on this special occasion . . . and we all
recognize the contributions he has made in the
arena of soil science. We also recognize his kind,
friendly, and gentle spirit. I don’t think George knows
how to throw a good “conniption fit” . . . as some of
us do.
Please join me in applauding Dr. Naderman on
a very successful career.
Awards Committee
M. Ray Tucker (presenter)
Elwood Black
Roberta Miller-Haraway
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
13
PLAT and NLEW:
Agricultural Tools for Management and Regulation
By Deanna L. Osmond
Introduction
The North Carolina Nutrient Assessment Tool,
Version 2.0, contains two field-scale assessment
tools: Nitrogen Loss Estimation Worksheet (NLEW)
and Phosphorus Loss Assessment Tool (PLAT).
NLEW was developed in response to the Neuse
Rules. In August 1998, the Neuse Rules became
law. These rules represent a series of regulations
that control point and nonpoint source discharges of
N into the Neuse.
As a result of the local option that was added to
the agricultural best management practice (BMP)
rules, producers can join a local strategy rather than
implementing mandatory BMPs. The local strategy
allows a county to determine where the approved
BMPs can be installed to obtain the 30% N
reduction. In addition, the local option provides a
few more alternatives to the list of BMPs, such as
unfertilized cereal cover crops and no-till corn in the
Piedmont, than the standard BMPs. In exchange for
this flexibility, however, the rules mandated
accountability.
The accounting and tracking tool that has been
developed to meet the requirements of the Neuse
Rules is NLEW. It was adopted by the N.C. Division
of Soil and Water Conservation in 1996 as the
method to estimate BMP effects on relative nutrient
dynamics for projects funded with Agriculture CostShare Program funds. It is also being used in the
Tar–Pamlico River Basin.
PLAT was developed in response to the new
USDA Natural Resources Conservation Service
(NRCS) nutrient management standard (590). The
charge was given that each state must assess P
status during nutrient management planning if
animal waste is involved or the field is within an
impaired watershed. Three selection strategies were
allowed (soil test, environmental test, and P index).
The North Carolina PLAT committee chose to use a
modified index or assessment method, PLAT. The
N.C. PLAT committee developed a unique P
assessment method designed for North Carolina
conditions.
Description of the N.C. Approach to
Phosphorus Loss Assessment
In 1999, the Phosphorus Loss Assessment
committee was formed to respond to and address
the changes in the NRCS nutrient management
policy and standard 590. This committee is
composed of members of NRCS, the N.C. Division
of Soil and Water Conservation, the N.C.
Department of Agriculture and Consumer Services
(NCDA&CS), and 11 faculty members of N.C. State
University.
Of the three options offered by the NRCS policy
and standard (soil test, soil threshold, and P-loss
index), the N.C. Phosphorus Action Committee
strongly endorsed the P-loss-index concept. The other
two approaches will be effective in North Carolina only
as components of an overall P-loss Assessment. In
order to avoid confusion with the agronomically based
NCDA&CS Phosphorus Index (P-I) reported on soil
testing forms, North Carolina chose the term
Phosphorus Loss Assessment Tool (PLAT).
The committee examined the P-Loss-Index
approaches proposed by NRCS national staff and
those proposed in other states to see how well these
approaches might work in North Carolina. These
approaches either assumed loss occurred primarily
through a single loss pathway (erosion), or focused
on a single system (i.e., poultry litter on pastures). In
addition, enormous reliance was placed on best
professional judgment in defining loss criteria and
values, as well as weighing the relative importance
of the criteria.
Deanna L. Osmond, Soil Science Specialist and Asst. Professor, NCSU Soil Science Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
14
Each of the proposed methods had serious
limitations for use in North Carolina, where
agricultural operations occur on over 480 soil series
(nearly 2000 mapping units), ranging across seven
soil orders, all drainage conditions, and nearly all
particle size classes. Animal wastes applied to these
sites come from dairy, beef, swine, layers, broilers,
and turkey operations, and each region of the state
has important and often unique animal and cropping
system traditions. In addition, North Carolina rules in
the Neuse and Tar–Pamlico river basins require
nutrient management plans for fertilized fields to
meet the new standard as well, a condition not
experienced in other states.
Because of the enormous diversity of situations
encountered within the state, it became apparent
that North Carolina needed to develop a new
method that allowed analysis of each loss pathway
separately for each site and that did not prejudge
the dominant loss mechanism. Based on this
generic approach and site-specific factors, the tool
uses only the appropriate source and transport
factors to calculate loss potential. Each loss
pathway is assigned a relative index for that factor
based on acceptable losses. The final results from
each pathway are summed to obtain the overall P
loss assessment for the site, as discussed below.
3. Subsurface Soluble P Losses Connected
with Surface Water. Direct movement of P from
soil to surface water is possible on sites with tile
drains and ditches that enter surface waters. Soils
with high P content and moderate or lower P
retention capacity may also contribute to surface
water through leaching and lateral flow from the field
since a high percentage of the near-surface
groundwater feeds into surface water channels.
LOSS PATHWAYS
Phosphorus loss occurs through four major
processes, any of which could be the dominant loss
pathway for a situation common in some part of the
state. One or more pathways may contribute to
significant P loss for a site.
ADVANTAGES OF THE N.C. PHOSPHORUS
LOSS ASSESSMENT TOOL
• Best professional judgment is minimized.
• One tool works for all situations. Multiple
worksheets with different ratings based on regions,
manure systems or cropping systems are
eliminated.
• Standard, routine inputs are used where
possible.
• Specific estimates are based on local conditions
and management.
• Implemented BMPs are integrated into the
assessment process. This allows PLAT to be used
as a planning tool as well as an assessment tool.
1. Sediment Carrying Soil-bound P. The largest
pool of P in a field is the soil itself. The sorting of
soil particles that naturally takes place during
erosion results in clays, which have the highest P
concentration, being carried with surface runoff: the
higher the soil test P level, the higher the P content
in eroded particles. Site-specific factors that reduce
sediment delivery to the stream (erosion control
practices, redeposition in the field, retention beyond
the edge of the field by buffers or other BMPs)
reduce P loss.
2. Runoff Carrying Soluble P. For a given soil,
the dissolved P concentrations in runoff increases
proportionally as the soil test P level increases. The
amount of P the soil releases to runoff at a given
soil test level also varies with soil texture, organic
matter content, and types of soil minerals. Very few
BMPs are effective in reducing runoff P losses.
4. Runoff Carrying Source P Applied to the
Surface. There is a strong relationship between P
application rate (as manure or fertilizer) and the
concentration of P in runoff following applications. In
manured or fertilized fields, the concentration of P in
surface runoff increases with the application rate,
the amount of applied P remaining on the soil
surface, and the solubility of the applied P.
PLAT RATINGS
Each pathway has a rating, and the ratings are
summed for the final rating. Rating ranges for PLAT
are low (0–25), medium (26–50), high (51–100), and
very high (>100). If the rating is high, then producers
can only apply the amount of P that will be used by
the crop. At a very high PLAT rating, no more P can
be applied, except in the case of starter fertilizer.
Description of Nitrogen Loss
Estimation Worksheet (NLEW)
In August 1998, the Neuse Rules became law.
These rules represented a series of regulations that
control point and nonpoint source discharges of N
into the Neuse. As a result of the local option that
was added to the agricultural BMP rules, producers
can join a local strategy rather than implementing
mandatory BMPs. As such, NLEW was developed.
15
OBJECTIVES
The purpose of the aggregate NLEW is to 1)
estimate a baseline N loading for agriculture for the
period 1991–1995, 2) allocate N goals to each
county within the Neuse basin, and 3) help county
advisory committees decide the distribution of
BMPs in their area.
In addition to the field-scale version of NLEW,
an aggregate version was developed. County-level
agency personnel used the aggregate version to
determine BMP scenarios to obtain the mandated
30% N reduction. After two years of implementation,
the actual BMPs that had been installed or used
were entered into NLEW to determine the percent N
reduction for each county. By May 2002, N reduction
by the agricultural community was 34%. As
additional counties continue to implement BMPs,
total N reduction will be even greater. Without
NLEW, this accounting process would have been
impossible.
ASSUMPTIONS ABOUT NLEW
• The majority of N lost in a cropping system
moves as soluble N.
• The majority of available N within the soil
system is either used by the crop or moved through
the soil system into the shallow groundwater.
• The agricultural system is at semi-steadystate.
• The tool is reflective of biophysical processes
occurring in the cropping system.
• Simplifying assumptions are used throughout
the worksheet.
• Inputs for the worksheet are readily available.
Acknowledgments
The interagency PLAT committee consisted of
Steve Hodges, Robert Evans, Wendell Gilliam, John
Havlin, Amy Johnson, Gene Kamprath, Nathan
Nelson, Deanna Osmond, John Parsons, Wayne
Skaggs & Phil Westerman (NCSU); Richard Reich &
David Hardy (NCDA&CS); Roger Hansard & Lane
Price (USDA–NRCS); and Carroll Pierce and Steve
Coffey (NCDENR). The interagency NLEW
committee consisted of Steve Hodges, Gene
Kamprath, Deanna Osmond & Noah Ranells
(NCSU); Richard Reich & Jim Cummings
(NCDA&CS); Roger Hansard (USDA–NRCS); Rich
Gannon, Lin Xu & Steve Coffey (NCDENR).
CONCEPTUAL FRAMEWORK FOR NLEW
Since NLEW will be applied to a minimum of
120,000 fields in the Neuse River Basin (average
field size in North Carolina is 10 acres or less), input
data need to be readily attainable. Inputs needed for
the accounting tool are soil type for the field, crop,
field size (acres), N fertilizer rate (lbs/acre), realistic
yield expectation (RYE) for the crop, cover crop type
(if grown), use of BMPs, and the area that the BMPs
affect. A diagram for the field-scale NLEW version
appears in Figure 1.
Figure 1. Field-scale NLEW.
SOIL MAP
UNIT
CROP
(acres)
SOIL
GROUP
OPTION:
Client RYE
CURRENT
N RATE
BMPS
BMP acres
affected
RYE N RATE
EXCESS
N
N PARTITION
CROP N
UPTAKE
TOTAL
SUBSURFACE N
SURFACE N
SUBSURFACE
N
CEREAL
COVER CROP
SUBSURFACE N
BMP
N SURFACE LOSS
N SUBSURFACE LOSS
ESTIMATED N LEAVING TARGETED
AREA
16
Response of Cotton to Soil P and K Gradients
in Long-term Fertility Plots
By Carl R. Crozier, F.R. (Bobby) Walls, David H. Hardy, Raymond D. Coltrain,
J. Steven Barnes, and John W. Smith
Abstract
This study characterizes the responses of
cotton to P and K gradients at three sites in North
Carolina and evaluates currently used soil and
plant tissue critical levels. Research was conducted
at the Peanut Belt Research Station on a Goldsboro
fine loamy sand (1999, 2002), the Piedmont
Research Station on a Hiwassee clay loam (2002),
and the Tidewater Research Station on a
Portsmouth fine sandy loam (1998, 1999). Standard
laboratory procedures of the N.C. Department of
Agriculture and Consumer Services (NCDA&CS)
were used for all analyses. Linear-plateau
regressions were used to identify the optimum soil
or plant nutrient concentration.
Optimum soil test K concentrations were found
to be lower than the soil test threshold (86 index
value), which was 1.2–2.2 times higher than the
optimum values in our study. Leaf P, leaf K, and
petiole K optimum concentrations were similar to
currently used critical levels; however, values are
sensitive to growth stage.
Optimum soil test P concentrations were also
found to be lower than the soil test threshold (62
index value) but similar to a previously published P
response function developed for corn based also on
soil clay content. Optimum values for the
Portsmouth (40) and Goldsboro (30) soils were
similar to those predicted for 5–10% clay soils, while
optimum for the Hiwassee soil was much lower
(<15), similar to values predicted for corn grown on
soils with 20–40% clay.
Introduction
Although P and K responses have been
characterized for numerous grain crops and Irish
potato, very little data are available for cotton in North
Carolina. A recent study investigated cotton, corn, and
peanut but only at a single site (Cox and Barnes,
2002). Response of corn to soil P gradients has been
shown to depend on soil clay content (Cox and Lins,
1984; Cox, 1994), which varies widely in cotton fields
across the state. Reexamination of K response data is
also warranted due to recent concerns about possible
K deficiencies in higher yielding varieties, more
continuous cotton, reports of deficiencies from other
states, and more leaf data in conjunction with samples
collected for petiole nitrate determination.
Current P and K management
recommendations for cotton in North Carolina are
based on soil test levels (Hardy et al., 2003;
Hodges, 2002). Plant tissue analysis can be used to
assess the status of a current crop and as a basis
for recommending either fertilization of the next
crop or, in some cases, in-season fertilization of the
current crop (Mitchell and Baker, 2000; Crozier et
al., 2002). The objectives of this paper are to
characterize responses of cotton to P and K
gradients at three sites and to evaluate currently
used soil and plant tissue critical levels.
Carl R. Crozier (corresponding author), Ext. Specialist, V.G. James Research & Extension Center, Plymouth, NC
F.R. (Bobby) Walls, Assistant Director, NCDA&CS Agronomic Division, Raleigh, NC
David H. Hardy, Soil Testing Section Chief, NCDA&CS Agronomic Div., 4300 Reedy Creek Rd., Raleigh, NC
Raymond D. Coltrain, Ag Research Superintendent, Piedmont Research Station, Salisbury, NC
J. Steven Barnes, Ag Research Superintendent, Peanut Belt Research Station, Lewiston-Woodville, NC
John W. Smith, Ag Research Superintendent, Tidewater Research Station, Plymouth, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
17
Materials and Methods
Tests were conducted on three sites that have
been in long-term crop production: a Goldsboro fine
loamy sand at the Peanut Belt Research Station in
Lewiston (1999, 2002), a Hiwassee clay loam at
the Piedmont Research Station in Salisbury
(2002), and a Portsmouth fine sandy loam at the
Tidewater Research Station in Plymouth (1998,
1999). Fertilizer treatments have been applied
intermittently since the establishment dates of
each test (Table 1). The Peanut Belt site is the
same one used by Cox and Barnes (2002), but
maximum K application rates have been raised to
increase the likelihood of attaining yield plateau
levels.
Soil test P treatments are present at all sites,
but K treatments are only present at the Peanut
Belt and Piedmont sites. Soil samples collected
from all sites were analyzed by the NCDA&CS
Agronomic Division Laboratory, using Mehlich-3
extractant with P and K reported as an index
value (Hardy et al., 2003). All field tests were
conducted with replications based on a
randomized complete block design (Table 1).
Fertilizers were applied preplant as broadcast
triple superphosphate (0-46-0) or muriate of potash
(0-0-60) at the specified rate. Standard agronomic
management practices were followed, including
lime, N, and micronutrient fertilizer applications.
Yield data were obtained either by mechanized
harvest of 100 feet of crop row (Peanut Belt), or by
hand harvest of 20 feet of crop row (Piedmont and
Tidewater). Total seed cotton weights were adjusted
based on a standard factor of 40% lint weight.
Leaf and petiole samples were collected on
multiple dates in the 1999 and 2002 trials at the
Peanut Belt and Piedmont Research Stations.
Statistical analyses were performed using linearplateau regression of the effect of soil or plant tissue
nutrient concentration on lint yield using the NLIN
procedure (SAS Institute Inc., 1990). Optimum
Table 1. Field sites and characteristics.
Research
Sta. (yrs)
Soil
Date
Established
#P
P-I
Trt4 Gradient
#K
Trt.5
K-I
Gradient
Reps
Plot
Size (ft)
Peanut Belt1 Goldsboro
(1999, 2002) fine loamy
sand
1982
4
7–79
3
16–80
4
24x50
Piedmont2
(2002)
1985
4
0–12
4
36–130
4
19x45
1966
5
17–91
0
----
6
21x174
Hiwassee
clay loam
Tidewater3
Portsmouth
(1998, 1999) fine sandy
loam
1
Additional treatments not discussed here include pH and poultry litter rates.
2
Uniform P and K applications have been made in some years when not designated for research use.
3
Initially K treatments were present but have been discontinued. In addition to annual rates of application, initial P
level subplots were established in 1966, which are no longer detectable based on either crop yield or soil or tissue
P concentration.
4
P2O5 application rates: Peanut Belt — 0, 20, 40, and 80 pounds per acre annually from 1999–2002, with these
same rates applied intermittently from 1982–1998; Piedmont — 0, 20, 40, and 80 pounds per acre in 2002, with
intermittent application from 1985–1995 and some uniform applications from 1995–2001; Tidewater — 0, 20, 40,
80, and 120 pounds per acre 1998 and 1999, with intermittent application from 1966–1997.
5
K2O application rates: Peanut Belt — 0, 50, and 100 pounds per acre annually from 1999–2002, but only 0, 33,
and 66 pounds per acre applied intermittently from 1982–1998; Piedmont — 0, 20, 40, and 80 pounds per acre in
2002, with intermittent application from 1985–1995 and some uniform applications from 1995–2001.
18
nutrient concentration was considered to be the
lower limit of the plateau portion of the function.
Data were compiled across site-years by calculating
the mean estimated optimum x-axis value.
Results and Discussion
Fertilizer treatments resulted in gradients of soil
and leaf tissue concentrations across the plots. Yield
responses to the soil K gradient and plateaus were
observed for all three site-years (Figures 1, 2).
Likewise, yield increases and plateaus were
identified as leaf K and petiole K concentrations
increased for all site-years (Figures 1, 2).
The mean optimum soil K-index value for the
Peanut Belt and Piedmont sites was 51, which is
lower than the soil test threshold value of 86 (Figure
3) but higher than the value of 20 recently reported
by Cox and Barnes (2002). Cox and Barnes
observed a critical soil test K level only one of three
years, suggesting that the soil test levels achieved
in their study were not sufficiently high.
Annual fertilizer application rates were
increased for our study, and maximum soil test K
levels have increased from values of 24–30 index
scale reported by Cox and Barnes to values of 55–
75 reported here. Optimum leaf K concentrations of
our study (0.98%) and by Cox and Barnes (0.9%)
were between the lower limits of the currently used
sufficiency ranges for the vegetative/early bloom
stage (1.5–3.0%) and the late bloom stage (0.75–
2.5%).
Samples in our study were collected one week
after first bloom, while Cox and Barnes sampled at
mid-bloom (approximately three weeks after first
bloom). Since the total bloom period lasts about
seven weeks, our calculated optimum leaf K
concentration reasonably fits between the critical
levels based on data from the vegetative/early
bloom stage and the late bloom stage. Optimum
petiole K concentration from our study was 3.35%,
which is similar to the lower limit of the sufficiency
range (4.0–5.5%) at first bloom in California (Basset
and MacKenzie, 1976).
Yield responses to the soil P gradient were
observed for all five site-years (Figures 4–6), with
plateaus identifiable for all cases except the
Piedmont (Figure 6). Likewise, yield increased as
leaf P concentration increased, with plateaus
identified for all 5 site-years (Figures 4–6).
Considering that a yield plateau was reached at the
Piedmont site with respect to leaf P concentration
data, the soil test range shown is probably very near
the plateau level for this site. Although not possible
to specify an optimum soil P-index value, the best
estimate appears to be 15 on the index scale.
The mean optimum soil P-index value for the
Tidewater and Peanut Belt sites was 35, which is
lower than the soil test threshold value of 62 but
higher than the value of 13 recently reported by Cox
and Barnes (2002). Since fertilizer K rates did not
appear sufficient during the Cox and Barnes study,
this may have reduced the ability of the crop to
respond to P increases. Optimum values for these
two sites are similar to values projected for corn
grown on soils with 5–10% clay (Figure 7, based on
Cox and Lins, 1984).
Our estimate of the optimum P-index value for
the Piedmont site is similar to values projected for
soils with 20–40% clay. Although we did not analyze
our soils for clay, standard soil survey data suggest
the Hiwassee, particularly if eroded to expose the Bt
horizon, has a higher clay content than the
Goldsboro and Portsmouth soils. Our field
observations noted the clayey nature of the
Piedmont site, the loamy sand of the Peanut Belt
site, and the sandy loam of the Tidewater site.
Optimum leaf P concentrations of our study (0.26%)
and by Cox and Barnes (0.21%) were similar to the
lower limit of the currently used sufficiency range
(0.2–0.65%) for the vegetative/early bloom stage.
Conclusions
Based on data from our study and work by Cox
and Barnes (2002), yield responses to P and K are
not likely if soil test indexes are high enough so that
no fertilizer is recommended (>62 soil P-index, >86
soil K-index). The safety margin for P is especially
large for soils with high clay content. Leaf P, leaf K,
and petiole K critical levels appear to provide a
useful verification of sufficiency when adjusted to
the appropriate growth stage.
Acknowledgments
Funding has been provided by Cotton
Incorporated, Project #01-992NC. Several farmers
allowed use of their fields for experimental plots.
Additional plot management assistance was
provided by D. Davenport and the staffs of the
Tidewater, Piedmont, and Peanut Belt Research
Stations.
19
Peanut Belt Research Station, 1999
a)
Tissue K (%)
0
1
2
3
4
5
Lint Yield (lb/acre)
1000
leaf +1wk
y = -479 + 775 x
if x < 1.28, R2 = 0.95
800
soil
y = -202 + 16.6 x
if x < 43, R2 = 0.93
600
400
petiole +1wk
y = -357 + 215 x
if x < 4.06, R2 = 0.95
200
0
0
20
40
60
80
100
Soil K Index (M-3 meq/100cm3 x 200)
Peanut Belt Research Station, 2002
b)
Tissue K (%)
0
1
2
3
4
5
Lint Yield (lb/acre)
1400
leaf +1wk
y = -345 + 1442 x
if x < 0.83, R2 = 0.88
1200
petiole +1wk
y = -2 + 309 x
if x < 2.68, R2 = 0.84
1000
800
600
400
soil
y = -380 + 33 x
if x < 37, R2 = 0.85
200
0
0
20
40
60
80
100
Soil K Index (M-3 meq/100cm3 x 200)
Figure 1. Yield response of cotton to soil, leaf, and petiole K levels at the Peanut Belt Research
Station: a) 1999, b) 2002. Vertical lines indicate optimum soil K-index and leaf and petiole K
concentrations.
20
Piedmont Research Station, 2002
Tissue K (%)
0
1
2
3
4
5
Lint Yield (lb/acre)
1000
800
leaf +1wk
y = -402 + 1074 x
if x < 0.82, R2 = 0.52
petiole +1wk
y = -45 + 193 x
if x < 3.31, R2 = 0.62
600
400
soil
y = -167 + 7.9 x
if x < 72, R2 = 0.36
200
0
0
20
40
60
80
100
120
140
Soil K Index (M-3 meq/100cm3 x 200)
Figure 2. Yield response of cotton to soil, leaf, and petiole K levels at the Piedmont Research Station,
2002. Vertical lines indicate optimum soil K-index and leaf and petiole K concentrations.
Potassium Recommendations
250
General NCDA&CS relationship for Cotton
y = 0.012 x 2- 2.9 x + 165
K2O (lb/ac)
200
150
Peanut Belt [40]
100
Piedmont [72]
50
0
0
20
40
60
80
100
120
Soil K Index (M-3 meq/100cm3 x 200)
Figure 3. Potassium fertilizer recommendations based on soil K-index.
140
21
Tidewater Research Station, 1998
a)
Leaf P (%)
Lint Yield (lb/acre)
0.0
1400
0.1
0.2
0.3
0.4
0.5
1200
1000
800
soil
y = 366 + 19.6 x
if x < 42, R2 = 0.64
600
400
leaf +1wk
y = 104 + 4594 x
if x < 0.24, R2 = 0.84
200
0
0
20
40
60
80
100
Soil P Index (M-3 ppm/1.2)
Tidewater Research Station, 1999
b)
Leaf P (%)
Lint Yield (lb/acre)
0.0
1000
0.1
0.2
0.3
0.4
0.5
soil
y = -44 + 16.6 x
if x < 39, R2 = 0.60
800
600
400
leaf +1wk
y = -506 + 5308 x
if x < 0.21, R2 = 0.61
200
0
0
20
40
60
80
100
Soil P Index (M-3 ppm/1.2)
Figure 4. Yield response of cotton to soil and leaf P levels at the Tidewater Research Station: a) 1998,
b) 1999. Vertical lines indicate optimum soil P-index and leaf P concentrations.
22
Peanut Belt Research Station, 1999
a)
Leaf P (%)
Lint Yield (lb/acre)
0.0
1000
0.1
0.2
0.3
0.4
0.5
soil
y = 204 + 10.3 x
if x < 30, R2 = 0.55
800
600
400
leaf +1wk
y = -70 + 1952 x
if x < 0.29, R2 = 0.65
200
0
0
20
40
60
80
100
Soil P Index (M-3 ppm/1.2)
Peanut Belt Research Station, 2002
b)
Leaf P (%)
Lint Yield (lb/acre)
0.0
1400
0.1
0.2
0.3
0.4
0.5
soil
y = 122 + 25.4 x
if x < 29, R2 = 0.73
1200
1000
800
600
400
leaf -1 wk
y = -682 + 4758 x
if x < 0.31, R2 = 0.76
200
0
0
20
40
60
80
100
Soil P Index (M-3 ppm/1.2)
Figure 5. Yield response of cotton to soil and leaf P levels at the Peanut Belt Research Station: a)
1999, b) 2002. Vertical lines indicate optimum soil P-index and leaf P concentrations.
23
Piedmont Research Station, 2002
Leaf P (%)
Lint Yield (lb/acre)
0.0
1000
0.1
0.2
soil
y = 233 + 27.9 x
R2 = 0.33
800
0.3
0.4
0.5
leaf -1wk
y = -1079 + 5982 x
if x < 0.24, R2 = 0.32
600
400
200
0
0
20
40
60
80
100
Soil P Index (M-3 ppm/1.2)
Figure 6. Yield response of cotton to soil and leaf P levels at the Piedmont Research Station, 2002.
Vertical lines indicate optimum soil P-index and leaf P concentrations.
Phosphorus Recommendations
200
General NCDA&CS relationship for Cotton
(& corn, soybean, small grains on min. soils)
P2O5 (lb/ac)
y=150-(3.2x)+(0.014x2 )
150
Based on Cox & Lins, 1984
y=218-(3.43x)+( 0.147 clay 2)-(0.357x clay )2
1%
100
Piedmont [15?]
(Hiwassee Bt 35-60%)
5%
10%
Peanut Belt [30]
(Goldsboro 5-15%)
50
20%
Tidewater [40]
(Portsmouth 5-25%)
40%
0
0
20
40
60
80
100
Soil P Index (M-3 ppm/1.2)
Figure 7. Phosphorus fertilizer recommendations based on soil P-index alone, or based on a function
including both P-index and clay content.
24
References
support of potassium recommendations for cotton.
Soil Sci. Soc. N.C., Proc. 45: 23–27.
Bassett, D.M., and A.J. MacKenzie. 1976. Plant
analysis as a guide to cotton fertilization. p. 16–17.
In H.M. Reisenauer (ed.) Soil and plant-tissue
testing in California. Coop. Ext. Serv. Bull. 1879.
Univ. of California, Davis, CA.
Hardy, D.H., M.R. Tucker, and C.E. Stokes. 2003.
Crop fertilization based on North Carolina soil tests.
Circ. No. 1. North Carolina Dep. Agric. and
Consumer Serv. Agron. Div., Raleigh.
Cox, F.R. 1994. Current phosphorus availability
indices: characteristics and shortcomings. p. 101–
113. In Soil testing: prospects for improving nutrient
recommendations. SSSA, Madison, WI.
Cox, F.R., and J.S. Barnes. 2002. Peanut, corn,
and cotton critical levels for phosphorus and
potassium on Goldsboro soil. Commun. Soil Sci.
Plant Anal. 33:1173–1186.
Cox, F.R., and I.D.G. Lins. 1984. A phosphorus soil
test interpretation for corn grown on acid soils
varying in crystalline clay content. Commun.
Soil Sci. Plant Anal. 15:1481–1491.
Crozier, C.R., F.R. Walls, L.G. Ambrose, and W.
Nixon. 2002. Soil, leaf and petiole analysis data in
Hodges, S.C. 2002. Fertilization. p. 40–54. In 2002
Cotton information. Publ. AG-417. North Carolina
Coop. Ext. Serv., Raleigh.
Mitchell, C.C., and W.H. Baker. 2000. Plant nutrient
sufficiency levels and critical values for cotton in
the southeastern U.S. [Online]. In C.R. Campbell
(ed.) Reference sufficiency ranges for plant analysis
in the southern region of the United States. S.
Coop. Ser. Bull. 394. North Carolina Dep. Agric.
and Consumer Serv., Raleigh. Available at http://
www.ncagr.com/agronomi/saaesd/cotton.htm
(posted Jul. 2000; verified 21 Oct. 2003)
SAS Institute, Inc. 1990. SAS/STAT user’s guide,
version 6, fourth edition. SAS Institute, Cary, NC.
25
Comparison of Bucket-wheel Spoil and
Phosphogypsum/Clay Blend
as Substrates for
Nonriverine Wet Hardwood Forest
Restoration
By Ross L. Andrews and Stephen W. Broome
Phosphate mining in Beaufort County, NC,
impacts a rare plant community type—nonriverine
wet hardwood forest (NRWHF). Reclamation of land
after mining uses three byproducts of mining: high
pH dolomitic clay tailings and low pH
phosphogypsum combined to create the neutral
“blend,” and the top 20–30 feet of material removed
by the bucket wheel (bucket-wheel spoil). The
objective of this study was to determine the
feasibility of using these byproducts as substrates
for restoring NRWHF.
A field study measured survival and growth of
11 trees and 4 shrubs planted in replicated plots of
bucket-wheel spoil and phosphogypsum–clay blend.
A greenhouse experiment compared growth of four
oak species on bucket-wheel spoil,
phosphogypsum–clay blend, native topsoil
(sterilized and unsterilized), and a commercial
potting mix. Half of the pots in each treatment were
fertilized using a complete nutrient solution with a
nitrogen concentration of 100 ppm.
Tree height on topsoil was significantly greater
than on both phosphogypsum–clay blend and
bucket-wheel spoil. There was no significant tree
height difference between phosphogypsum–clay
blend and bucket-wheel spoil. Among oak species,
Quercus pagodafolia showed significantly greater
height than Q. michauxii, Q. nigra, and Q. laurifolia
on all substrates. Field data from one growing
season showed greater plant growth and survival on
bucket-wheel spoil than on the phosphogypsum–
clay blend.
Ross Lester Andrews (corresponding author), Graduate Student, NCSU Soil Science Dept., Raleigh, NC
Stephen W. Broome, Professor, NCSU Soil Science Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
26
Nutrient Application Uniformity
with Wastewater Irrigation Systems
By Karl A. Shaffer and Graham F. Aldridge
Abstract
Crop land and pasture land in North Carolina
are irrigated at agronomic rates with many millions
of gallons of wastewater. Proper application
involves the need to understand
1) crop nutrient demands and application
windows,
2) soil and site limitations for wastewater
irrigation, and
3) irrigation equipment capabilities and
limitations.
The design and operation of the wastewater
application system is crucial in ensuring the
environmental sustainability and public acceptance
of this form of wastewater treatment and re-use.
Several types of irrigation systems are used to
apply wastewater. System selection is often a
function of the size of the facility, the layout of the
fields used for irrigation, and owner and designer
preferences. Some irrigation systems are inherently
more uniform in their application, theoretically
reducing the potential for environmental risks. This
paper provides data on the major types of systems
used in North Carolina and discuss the implications
of these systems in terms of cropping system
management, irrigation system management, and
potential environmental benefits or liabilities.
Introduction
Wastewater irrigation is used extensively for
application of liquid animal manures and
wastewaters from industrial and municipal sources.
Some wastewater types, such as municipal
wastewater, are very dilute and often have relatively
little odor. Other wastewaters, such as those from
concentrated animal feeding operations, may be
very concentrated due to the waste management
system employed. Food processing wastewater may
also have relatively high concentrations of organic
components, salts, and odors.
All wastewater must be handled appropriately
when using a land application system. However,
some of the high strength or high odor wastewaters
must be handled with additional oversight to ensure
minimal odor concerns and to ensure adequate
application uniformity for agronomic and
environmental concerns.
In the southeastern United States, a variety of
irrigation system types are used to apply
wastewater. Equipment selection is often based on
cost and the site features (area, topography) that
may favor one type of equipment over another.
Other selection factors include life expectancy,
maintenance requirements, tolerance to wastewater
constituents, ease of operation, types of crops to be
grown, and regulatory requirements.
Irrigation System Types Monitored
This study monitored four types of irrigation
systems used for wastewater application. These
systems types are
• center pivot,
• boom sprayer,
• hard-hose traveler with big gun, and
• solid-set impact (model 70) sprinklers.
Further, several sprinkler or nozzle types and
variable pressures were used. The purpose was to
monitor both application uniformity and the potential
Karl A. Shaffer, Extension Associate / Waste Management, NCSU Soil Science Dept., Raleigh, NC
Graham F. Aldridge, Field Site Manager, Land Application Training and Demonstration Center, NCSU Soil
Science Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
27
for drift of wastewater. Several factors influence drift
of irrigated water, including
• nozzle type,
• nozzle size,
• pressure at discharge point,
• droplet size,
• nozzle height (height of discharge),
• wind speed, and
• site and topographic conditions (proximity to
woods or windbreaks, slope, etc.).
The first five factors can be controlled either
through the design stage or the operational
management of the system. Site conditions such as
windbreak installations can be used, and site
selection can have a bearing on potential drift.
These factors, however, were not addressed in this
study.
The factors that were used as variables include
operating pressure and droplet size, which is a
function of the sprinkler/nozzle type. Not all nozzles
are interchangeable on the four systems used.
Further, it was not the intent of this study to evaluate
all possible settings of nozzle type, pressure, and
discharge height; but rather to evaluate several
system types that are commonly used for
wastewater application.
Site Conditions
All systems were operated in light winds. Wind
speed was measured with two instruments. Winds
varied from 3 to 5.4 miles per hour. All systems were
run at sufficient length to make measurements that
accounted for the upper wind velocities. Therefore, it
is assumed that all measurements for drift are based
on the maximum wind speed. The uniformity
determinations were made over several days under
similar wind conditions. Uniformity measurements
should be assumed to be for average wind
conditions as opposed to maximum measurements.
Materials and Methods
The following list of equipment was used in this
evaluation. Where trade names are used, no
endorsement is implied. Equipment brands were
used based on the availability for the study and the
relevance to wastewater irrigation. Many other
products exist for irrigating wastewater, and it was
not the intent of the study to do an exhaustive
search over the range of products.
• A boom sprayer was attached to an ABI
hard-hose traveler. The boom was adapted from one
used in chemigation. The boom span was 135 ft. Two
nozzles were used for the study. A brass nozzle with a
2.5-mm orifice was originally installed on the boom.
The nozzle spacing was 30 inches. This system was
operated at inlet pressure to the boom of 14 and 35
psi. The second nozzle selection was a Nelson
trashbuster 10 GPM nozzle. This nozzle works on the
principle of varying orifice size based on pressure.
Nozzle spacing was 90 inches. This particular nozzle
was selected because it projects water as a stream
rather than creating small droplets. This nozzle was
also operated at 14 and 35 psi.
• A Valley center pivot was used. One span
was outfitted with three nozzle packages. These
packages were 1) Nelson trashbuster (same as
above) operated at 15 psi; 2) Senninger superspray
(a nozzle that also projects water in a stream vs. a
droplet discharge) with varying nozzle sizes
specifically adapted to the pivot for uniformity and
operated at 15 psi; and 3) Senninger model 50
impact sprinklers operated on the top of the boom
span and operated at 35 psi. Note that the discharge
height for the trashbuster and superspray were
approximately 40 inches (height varies with terrain),
and the height of the impact sprinklers was 13 ft.
• A Cadman hard-hose traveler model 2625
mounted with a Rainbird model 100 gun was
operated at 60 psi. Nozzle height was 54 inches,
and the nozzle was a taper-bore style with 0.55-inch
orifice.
• A solid-set sprinkler system with lateral
spacing of 80 feet and sprinkler spacing of 80 feet
(square pattern) using Senninger model 70
sprinklers with 9/32-inch nozzles was operated at 50
psi. Discharge height was 18 inches.
FIELD SETUP
All irrigation options were run at typical
operating pressures designed for normal wastewater
application settings, including design features for
overlap to obtain what is considered to be acceptable
application uniformity. Each system was run
independently under similar field conditions with winds
ranging from 3 to 5.4 miles per hour. Occasionally, the
wind speed would slow to less than 2 miles per hour
for very brief periods. These conditions are typical of
field operation in the southeastern United States.
Conditions such as humidity and barometric
pressure—while possibly having some influence
over drift, uniformity, and odor—were considered to
be much less significant and thus not measured.
For each system type, uniformity was
determined based on a minimum of three irrigation
cycles for the system. An explanation of how
uniformity was measured follows.
28
For each system type, three measurements
were taken. The first was the actual wetted diameter
of the selected sprinkler at the varying pressures
used. The second measurement—and the most
subjective—is referred to as “visual” mist. This is
where a bystander can actually see and feel mist
from the sprinkler system. This measurement was the
average distance at which 2 to 12 individuals sensed
the mist. Individuals started on the windward side of
the sprinkler and walked toward the sprinkler, directly
into the prevailing wind, until mist was noticed.
The third measurement used moisture sensor
cards (TeeJet cards), which are designed to monitor
chemical spray for drift. The cards are sensitive and
can detect extremely fine moisture particles that
humans cannot. A series of cards was posted at
10-foot intervals on the downwind side of the
sprinklers, and measurement to the last card that
received drift is the measured drift figure.
UNIFORMITY
The uniformity of application was measured for
each sprinkler setup. The uniformity measurements
were not used to support the potential for drift of
wastewater. Rather, they determined the uniformity
achieved as related to application of wastewater
with particularly high concentrations of nutrients or
some other parameter that may affect crop growth
or environmental hazard.
Application uniformity was measured using
guidelines obtained in N.C. Cooperative Extension
Bulletins AG-553-1, AG-553-2, and AG-553-3.
Methods vary somewhat depending on the type of
system being operated, but the general premise is
that a representative area is evaluated by collecting
irrigated water discharge with collection containers.
The variability of the collected catch is reviewed and
a uniformity coefficient is obtained. For example, if
collection containers were set and all containers
received 0.5 inch of wastewater from an irrigation
system, that system would be determined to be
100% uniform, as there was no variance across the
entire system. A uniformity coefficient is calculated
as follows:
Uniformity = Average catch – Average deviation × 100%
Average catch
where Average catch is the average of containers
within the effective wetted area and Average
deviation is the average of all deviations from
average within the effective wetted area.
System uniformity can be changed substantially
based on design specifications. The systems used in
this study were designed to obtain an acceptable
level of uniformity while being practical in terms of
installation simplicity and cost. A uniformity of 70%
or higher can be consistently achieved with many
types of irrigation systems and, for purpose of this
study, is determined to offer adequate uniformity for
most types of wastewater. Of course, as mentioned
above, if specific wastewater constituents warrant,
uniformities of a higher degree may need to be
considered. Likewise, wastewater that is very dilute
in its constituents, such as typical municipal
wastewater, does not require such a high level of
application uniformity.
Results and Discussion
WASTEWATER DRIFT
Wastewater drift is significantly higher when
wastewater is discharged causing tiny water
droplets. Tiny droplets can be caused by either the
type of sprinkler, nozzle design, or the operating
pressure. Table 1 summarizes the results from the
field study for wastewater drift. Examples of high
drift from Table 1 include the sprinklers operated
above 50 psi (solid set and hard-hose traveler),
sprinklers with high discharge heights and moderate
pressure (center pivot impact sprinklers), and
nozzles that are designed to discharge the water
into fine droplets (pesticide brass nozzles).
Sprinklers that are designed to discharge water in a
stream or into large droplets as opposed to a fine
spray are much more effective at reducing drift than
other nozzles.
Lower pressure also allows for less drift;
however, pressure and adequate water distribution
are a function of the nozzle, so many nozzles do not
perform well at pressures below 35 psi. Nozzles that
do perform well at ranges of 10–15 psi are typically
designed for drop fittings on a center pivot, linear
move, or boom sprayer system.
SYSTEM UNIFORMITY
System uniformity is somewhat related to drift.
However, the purpose of discussing uniformity here
is to relate the system types as they would apply
wastewater that may have high constituents of
particular concern for crop growth or environmental
sensitivity. It is important to note that uniformity of a
particular system depends on the nozzle selected,
the nozzle or sprinkler spacing, the operating
pressure, and age of the equipment. This was not an
exhaustive study on uniformity for various irrigation
systems. The systems were operated as designed,
for practical, economic wastewater application.
29
Table 1. Wetted radius, visual drift, and measured drift from various nozzles and pressures used in
wastewater application.
Equipment
type
Nozzle
type
Nozzle
size
Operating
pressure
(psi)
Wetted
radius
(feet)
Visual
drift1
(feet)
Measured
drift1
(feet)
Boom sprayer
Pesticide brass
2.5 mm
14
8
105
240
Boom sprayer
Pesticide brass
2.5 mm
35
9
185
300
Boom sprayer
Nelson trashbuster
variable
14
14
10
20
Boom sprayer
Nelson trashbuster
variable
35
16
45
90
Solid set
Senninger model 70
9/32 in
50
65
95
260
Hard-hose traveler
Rainbird model 100
0.55 in
60
121
360
520
Center pivot
Senninger model 50
7/32 in
35
42
170
360
Center pivot
Nelson trashbuster
variable
15
14
14
20
Center pivot
Senninger superspray
variable
15
14
18
30
1
Measured from edge of wetted radius
Table 2. Uniformity data for Cadman 2625 hard-hose traveler with Rainbird 100 model gun at 60 psi.
Uniformity Coefficient = 88.
Rain gauge #
Distance from
center (feet)
Initial Catch
(inches)
L8
112.5
0.02
L7
97.5
0.15
L6
82.5
0.34
0.46
0.098
L5
67.5
0.35
0.42
0.058
L4
52.5
0.34
0.34
0.022
L3
37.5
0.36
0.36
0.002
L2
22.5
0.32
0.32
0.042
L1
7.5
0.30
0.30
0.062
R1
7.5
0.31
0.31
0.052
R2
22.5
0.34
0.34
0.022
R3
37.5
0.33
0.33
0.032
R4
52.5
0.36
0.36
0.002
R5
67.5
0.32
0.34
0.022
R6
82.5
0.31
0.46
0.098
R7
97.5
0.16
R8
112.5
0.07
NA
NA
0.362
0.043
Average
Corrected volume
(inches)
Deviation from
from average
Uniformity is calculated as follows: [(0.362 – 0.043) ÷ 0.362] × 100% = 88.12%
30
The center pivot, boom sprayer, and hard-hose
traveler systems all have comparable uniformity.
Table 2 shows data from the hard-hose traveler.
When the systems are operated in light wind (less
than 3 miles per hour), uniformity of 80 to 92%
efficiency was obtained. The solid-set system
consistently has less uniformity, with 60 to 70%
efficiencies being the most common. However, with
the solid-set system, uniformity over time in the
same field actually increases if one considers the
sum total of variability over several irrigation events.
The result is that uniformity of wastewater and its
constituents for a solid-set system approaches that
of other systems.
All uniformity calibrations described in this paper
are based on a design overlap of sprinklers from 20
to 40%, which is based on manufacturer’s
recommendations for proper spacing and overlap.
Where spacing of sprinklers is outside these design
conditions, uniformity is much less than the above
figures, and crop and environmental consequences
are much more likely.
Acknowledgments
Information used in this paper was partially
supported by the U.S. Environmental Protection
Agency via a 319 grant. The authors wish to
acknowledge the Land Application Training and
Demonstration Center of NCSU and its supporters
and contributors for use if its facility for this and
other related wastewater application programs. The
authors also wish to thank the particular vendors
who donated equipment used at the Land
Application Training and Demonstration Center of
NCSU for training, demonstration, and research
programs.
References
Evans, R.O., J.C. Barker, J.T. Smith, and R.E.
Sheffield. 1997. Field calibration procedures for
animal wastewater application equipment—
stationary sprinkler irrigation systems. Publ. AG553-1. North Carolina Coop. Ext. Serv., Raleigh.
Conclusions
The ability to reduce drift of wastewater from an
irrigation system depends on the ability to reduce
operating pressure and/or use sprinklers or nozzles
that deliver large droplets or streams of wastewater.
Equipment that allows for creation of fine droplets
allows wind drift of a significant nature. The volume
of wastewater lost due to wind drift is not always
substantial, but it carries odors and negative public
perception of wastewater irrigation.
Uniformity of wastewater irrigation application is
a function of the system type, design, and operating
parameters. Some system types are more efficient
at uniform application than others. Wastewater that
has high constituents of agronomic concern—which
may affect crop growth or environmentally sensitive
areas—may require highly uniform application to
maintain the environmental integrity of the system.
Evans, R.O., J.C. Barker, J.T. Smith, and R.E.
Sheffield. 1997. Field calibration procedures for
animal wastewater application equipment—hard
hose and cable tow traveler irrigation systems. Publ.
AG-553-2. North Carolina Coop. Ext. Serv.,
Raleigh.
Evans, R.O., J.C. Barker, J.T. Smith, and R.E.
Sheffield. 1997. Field calibration procedures for
animal wastewater application equipment—center
pivot and linear move sprinkler irrigation systems.
Publ. AG-553-3. North Carolina Coop. Ext. Serv.,
Raleigh.
Sopher, C.D., and J.V. Baird. 1982. Soils and soil
management, second edition. Reston Pub. Co.,
Reston, VA. 312 p.
31
Effective Sodium Management
for
Industrial Waste Land Application
By Steve A. Stadelman
Abstract
Land application of industrial wastes in general
has a higher risk of Na injury to soils due to the
common industrial use of Na-containing and highpH chemicals. The risk of Na damage to soils is
typically evaluated by calculating the sodium
absorption ratio (SAR) of the waste prior to land
application. For industrial wastes the SAR is not an
accurate measure when the waste is Ca poor and
high in alkalinity, and Na damage can occur at
otherwise low SAR values. Carbonate (CO3-2) and
bicarbonate (HCO3-) alkalinity are commonly high in
industrial wastes streams and must be accounted
for by adjusting the SAR calculation. Calcium
addition to the soil is the most common method of
repairing soils with Na damage and should be
calculated based on an appropriate depth of soil
sampling. Soil extract testing of soils is a
supplemental tool that provides valuable
information on Ca application rates and overall
management decisions for control of Na.
Introduction
Agricultural reuse of municipal and industrial
wastes by land application is a widespread practice
in North Carolina that reduces the direct discharge
of nutrients and pollutants to streams. For waste
reuse to be sustainable, nutrients, metals, and other
constituents must be properly controlled and the
health of the soil–crop system adequately
maintained. One of the problems inherent to the
reuse of industrial wastes is higher dissolved salt
and Na content, which can require intensive
management in order to sustain soil and crop
health. These problems are more pronounced for
industrial wastewater spray irrigation than for
industrial residual land application due to generally
higher loading rates associated with spray irrigation.
This paper addresses management of Na in
industrial wastewaster spray irrigation.
Sodium Impact
Sodium is of concern for several reasons. Like
salts such as chloride, it can cause leaf burn in
sensitive crops if the concentration is too high.
Damage occurs from either leaf contact or
absorption by roots and translocation to leaves in
toxic concentrations. Sodium also contributes to
total salinity and osmotic wilting (Rhoades et al.,
1992).
Sodium is more frequently of concern because
of the dispersive effects it has on soil clays and the
subsequent physical alteration of soil structure and
reduction in soil infiltration and permeability (Bohn
et al., 1985; Tanji, 1996). Sodium is monovalent and
can displace divalent cations from exchange sites
on soil clays.
The cation exchange capacity (CEC) is a
measure of the capacity of the soil clays to absorb
and exchange cations. The amount of Na occupying
the CEC is referred to as the exchangeable sodium
percentage (ESP). In general, when the ESP
exceeds 15%, it commonly results in dispersion of
clays into pores, and water movement through the
soil is greatly reduced (Tanji, 1996). This leads to
sealing of the soil surface, saturation of plant roots,
and plant die off. Dispersion of clays can also
dramatically decrease subsoil permeability resulting
in severely decreased irrigation capacity.
SAR is a common measure on wastewater to
assess its potential for Na damage to soils. This
Steve A. Stadelman, Novozymes North America, Inc., Franklinton, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
32
ratio accounts for the negative effects of
monovalent Na+ and positive effects of divalent
Ca++ and Mg++ as follows:
SAR =
Na+ eq.
———————————————
sq. rt. {(Ca++ eq. + Mg++ eq.)/2}
Wastewater used for irrigation should be kept
below an SAR of 5 although higher SARs can be
tolerated (Rhoades et al., 1992; Tanji, 1996). Soils
with higher organic matter content will generally
tolerate a higher SAR in wastewater. For
wastewaters with high alkalinity and relatively low
Ca content, the SAR can severely underestimate
the potential for Na damage.
Effect of Alkalinity on SAR
Bicarbonate and CO3-2 alkalinity can strongly
influence the impact of Na+ on soils, especially if the
wastewater is Ca poor and alkalinity is very high.
When alkalinity greatly exceeds Ca++ and Mg++, it
increases the effectiveness of Na to disperse clays,
and soil pH typically will increase to 9 or more. This
high pH often results in nutrient deficiencies (e.g.,
Fe). Sodium will dominate the exchange sites
resulting in dispersion of clays and reduction in soil
infiltration and permeability. When alkalinity is high
and Ca is low, it takes less Na to cause soil damage
than predicated by the SAR.
Chemicals used in industrial processes can
result in excessive accumulation of HCO3- and CO3-2
in wastewater. Bicarbonate is produced by the
interaction of water and carbon dioxide as follows:
H2O + CO2 Ù H2CO3 Ù H+ + HCO3- Ù H+ + CO32The H+ is consumed by bases used in many
industrial processes (e.g., NaOH, KOH), which
drives the accumulation of HCO3-. At equilibrium in
water, pH will approach 8.4 with HCO3- as the
dominant form of alkalinity.
After wastewater is irrigated and enters the soil,
the pH can increase as the soil begins to dry out.
Calcium (and Mg) carbonate minerals will
precipitate as follows:
Ca++ + 2HCO3- Ù CaCO3 + H2O + CO2
As a result Na + and excess HCO3- are left in
solution and Na + can dominate the clay exchange
sites. The interaction of Na+ and HCO3- will
increase soil pH as will the hydrolysis of Na+ on
clay exchange sites, resulting in increases in pH
above 9 (Brady, 1984).
Effective Monitoring
There are two criteria that can be used to
effectively assess the Na and alkalinity effect. The
first is the Residual Sodium Carbonate (RSC), which
is calculated in units of meq L-1 as follows:
RSC = (HCO3- + CO3-2) - (Ca++ + Mg++).
The RSC calculates the residual alkalinity remains
after Ca++ and Mg++ have been consumed by
precipitation of carbonate minerals. The excess
alkalinity is then available to react with Na. This
measure is conservative because it does not
account for leaching losses of alkalinity.
The second assessment method involves
recalculating the SAR and accounting for Ca that is
consumed by alkalinity due to precipitation of
calcium carbonate (CaCO3) and is unavailable to
occupy soil clay exchange sites. The concentration
of Ca is adjusted downward in the SAR equation,
which causes the SAR to increase. This is referred
to as the adjusted SAR (Suarez, 1981). In this
method, the ratio of HCO3-/Ca++ calculated to obtain
an adjusted Ca concentration (Cax) to use in SAR
calculation. The Cax can be obtained from tabulated
data (Rhoades and Loveday, 1990). The value of
Cax is always lower than the original Ca, resulting in
the adjusted SAR > initial SAR.
adjusted SAR =
Na eq.
——————————————
sq. rt. {(Cax eq. + Mg eq.)/2}
The effect of alkalinity on the SAR can be quite
dramatic. As the following data indicate, wastewater
with an apparently adequate SAR (<10) has an
adjusted SAR of 14, and Na-related problems on
spray irrigation fields would be expected.
Ca++ (meq)
Mg++
Na+
HCO3CO2HCO3-/Ca++
Cax
RSC
SAR
Adj. SAR
5.0
0.46
14.0
10.4
0.21
2.08
1.5
5.2
8.5
14.1
33
Soil Testing
Sodium, Ca, Mg, and CEC are among the
parameters typically tested for soil samples in the
eastern USA. However, the data need to be
evaluated carefully because results typically reflect
whole soil analysis. As such, test results will not
allow distinction between Ca in CaCO3 that is
unavailable to exchange sites and Ca in soil water
that is available. In arid and semi-arid regions,
saturated paste extractions are routinely used for
soil salinity assessment and can provide more
reliable measure of the Na, alkalinity, and SAR
status of the soil. The use of whole soil and
saturated paste extracts together provides a more
complete assessment of the impact of Na and
alkalinity on the health of the soil–crop system.
Remediation of Sodium and
Alkalinity
There are several ways to reduce the impact of
Na and alkalinity on soils receiving wastewater. The
most common method is to add gypsum to the soil
to displace Na+ with Ca++ on the cation exchange
sites. Other methods of remediation include
reducing the amount of Na and high pH chemicals in
the industrial facility, but this may not be feasible
due to process requirements or economy. Soluble
Ca can be added to the wastewater prior to or during
irrigation. However, if alkalinity is high, it can require
a significant amount of Ca addition that may not be
economical. Likewise, acids can be added to the
wastewater to lower the alkalinity, but if alkalinity is
high acid addition will be expensive and most likely
prohibitive.
The most common method of remediating soils
is by the addition of Ca to the spray field, typically in
the form of gypsum (CaSO4 • 2H2O). The amount of
gypsum to be added is estimated by calculating the
amount of Na+ to be displaced by Ca++ from the clay
exchange sites by using the existing and target
ESPs as a specified depth using a given soil bulk
density (Tanji, 1996). This calculation is typically
provided in a condensed form to determine the
gypsum requirement for a 6-inch acre slice of soil
with an average bulk density (e.g., Wallace, 1995):
application rate exceeds a few tons per acre,
application should be spread out over several years.
If the intent of gypsum addition is to correct a
reduction in subsoil permeability, subsoiling or
another means of disrupting the dispersed clays
may be needed in conjunction with gypsum
additions. If the problem to be corrected is reduced
infiltration capacity due to surface sealing, broadcast
applications of gypsum may be sufficient.
Summary
Industrial wastewater spray irrigation facilities in
North Carolina are susceptible to Na problems on
spray fields due to the common use of Nacontaining chemicals and high-pH chemicals. The
use of high pH-chemicals can drive the
accumulation of HCO3- and CO3-2, which can result
in underestimation of the potential for Na to reduce
soil infiltration and permeability. The SAR
calculation can be adjusted for the effects of high
alkalinity on Ca availability to provide a more
accurate assessment of the potential for Na
damage. Testing of soils by whole soil and saturated
paste extracts can provide a more accurate
assessment of soils and potential for Na damage.
Gypsum addition is the most common method of
remediating soils with Na problems.
References
Bohn, H.L., B.L. McNeal, and G.A. O’Connor. 1985.
Soil chemistry. 2nd ed. Wiley-Interscience, New York.
Brady, N.C. 1984. The nature and properties of soils.
9th ed. Macmillan publishing, New York. 767 p.
Rhoades, J.D., A. Kandiah, and A.M. Mashali. 1992.
The use of saline waters for crop production. FAO
Irrigation and Drainage Paper 48. Food and
Agriculture Organization of the United Nations,
Rome. Available at http://www.fao.org/docrep/
T0667E/T0667E00.htm (posted Jul. 2000; verified
23 Oct. 2003)
= tons of pure gypsum/acre per 6-inch depth
Rhoades, J.D., and J. Loveday. 1990. Salinity in
irrigated agriculture. p. 1089–1142. In B. A. Stewart
and D. R. Nielsen (ed.) Irrigation of agricultural
crops. Agron. Monogr. 30. ASA, CSSA, and SSSA,
Madison, WI.
Rates of gypsum addition can range from a few
tons per acre to over 100 tons per acre. When the
Suarez, D.L. 1981. Relationship between pHc and
sodium absorption ratio (SAR) and an alternative
Gypsum Requirement = (ESPinitial- ESPfinal) × CEC × 0.172
34
method of estimating SAR of soil and drainage
waters. Soil Sci. Soc. Amer. J. 45:469–475.
Tanji, K.K. (ed.). 1996. Agricultural salinity
assessment and management. Manuals and
Reports on Engineering Practice No. 71. American
Society of Civil Engineers, New York. 619 p.
Wallace, A. 1995. Soil conditioners and amendment
technologies, volume 1: soil amendments. Wallace
Laboratories, El Segundo, CA.
35
Phosphorus Leaching in Acid Sandy Soils Following
Long-term Waste Applications:
Background Information and Preliminary Data
By Nathan O. Nelson and Robert L. Mikkelsen
Introduction
Poultry litter and anaerobic swine lagoon
effluent are common agricultural wastes that have
been historically applied to soils immediately
surrounding the animal production facilities to meet
N requirements of growing crops. In so doing, P has
been over applied by two to three times, resulting in
P accumulation and high soil P levels (Mikkelsen,
1997; Sharpley et al., 1996). The excess P in these
waste-amended soils can potentially be transported
from the field to adjacent surface water through
rainfall runoff, soil erosion, and leaching (Hansen et
al., 2002).
Studies have shown that the increased soil P
levels from long-term waste applications have
increased the risk of P loss to surface water
(McDowell and Sharpley, 2001; Sharpley, 1995).
Phosphorus additions to surface waters promote
eutrophication, or the excessive growth of algae and
aquatic plants, which leads to low dissolved oxygen
concentrations, fish kills, and general water quality
degradation (Correll, 1998). Because of the primary
role of P in the eutrophication of freshwater lakes
and rivers, it is advantageous to reduce P inputs to
water resources.
To assist in controlling P losses from wasteamended soils, the USDA Natural Resources
Conservation Service (NRCS) recently revised their
policy for nutrient management technical assistance
to include P-based waste application
recommendations (NRCS, 1999a). The revised
guidelines state that waste-based P applications
should not exceed crop P removal if the P index
rating is high or very high, if soil P levels exceed a
threshold value, or if soil test recommendations do
not recommend P additions (NRCS, 1999b). In
compliance with the updated NRCS standards, an
interagency committee headed by the N.C. State
University Soil Science Department has developed
the Phosphorus Loss Assessment Tool, which will be
used to determine the risk of P loss from agricultural
fields in North Carolina. This tool will be used to
evaluate the risk of P loss from four major
pathways: particulate P loss through erosion,
desorption from soil into runoff, release from applied
P sources (such as animal waste) into runoff, and
subsurface loss through leaching.
Because P adsorbs to soil colloids, much of the
research on P loss from agricultural fields has been
focused on surface transport of P via erosion,
desorption into runoff, and P release from applied P
sources. Phosphorus applied to soils with low or
medium soil test P will generally bind to the soil
through adsorption processes, thus inhibiting P
leaching. However, soils have a finite capacity to
adsorb P, referred to as the P adsorption capacity.
The amount of P adsorbed on soil surfaces relative
to the soil’s P adsorption capacity is referred to as
the degree of P saturation (DPS) (Schoumans and
Groenendijk, 2000). As soil test P increases, the
DPS also increases and a larger proportion of P
remains in solution, thus allowing for P to leach to
lower soil horizons (Figure 1). Underlying soil
horizons can gradually accumulate P to the point
where P leaching extends below the rooting zone.
The occurrence of P leaching is becoming more
widely observed now that it was previously.
Heckrath et al. (1995) found P concentrations in
excess of 2.5 mg L-1 in drainage water below soils
with a long-term history of fertilizer P applications.
Because organic soils and very sandy soils have low
P-sorption capacities (Fox and Kamprath, 1971;
Marconi and Nelson, 1984), P leaching on these
soils is of greater concern. Izuno et al. (1991) found
Nathan O. Nelson, Graduate Research Fellow, NCSU Soil Science Dept., Raleigh, NC
Robert L. Mikkelsen, Adjunct Professor, NCSU Soil Science Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
36
average P concentrations in excess of 1 mg L-1 in
drainage water leaving the Everglades Agricultural
Area, a region dominated by Histosols. Other studies
have found lower, yet still elevated, P concentrations
in drainage water from large lysimeters or tile-drained
fields (Turner and Haygarth, 2000; Leinweber et al.,
1999; Sims et al., 1998).
Phosphorus leaching is of particular concern
when waste is applied to acid sandy soils of the North
Carolina Coastal Plain. Rainfall and liquid waste
applications to these soils infiltrates rapidly, resulting
in little to no runoff or erosion, and as previously
mentioned, sandy soils have low P-adsorption
capacities. This combination of factors (high Papplication rates, high infiltration and percolation
rates, and low P-adsorption capacities) can lead to P
leaching and potential loss to shallow groundwater.
A recent survey of several animal production
facilities in the North Carolina Coastal Plain revealed
P leaching at depths greater than 120 cm (Ham,
1999). It is unlikely that P leaching in wasteapplication fields of this region is an isolated
occurrence. For example, over 25% of the soils
mapped in Sampson and Duplin counties have very
low P-adsorption capacities and are, therefore,
susceptible to P leaching (Figure 2). These same two
counties contain 7.2 million broilers, 3.9 million swine,
and 5.8 million turkeys, which produce an estimated
4,950 tonnes of excess P each year (NCSU Spatial
Information Research Lab, 2000).
Measuring the concentration of P in leachate
water is not always practical, and the amount can
depend more on past management than current
management strategies. Therefore, computer models
and relationships like that in Figure 1 can be used to
predict the P concentration in leachate based on
extractable soil P and other soil properties. Because
changes in P management may not be reflected in
soil or leachate P concentrations for several years,
computer models can also be used to predict the longterm effects of current changes in P management.
GLEAMS (groundwater-loading effects of agricultural
management systems) is a field-scale computer
simulation model that can be used to simulate P
movement in different agricultural systems over longterm simulation periods.
GLEAMS simulates the chemical and physical
processes in the soil system on a daily time-step,
including the simulation of hydrology and P flux. For
each day in the model simulation, both the water
balance and the flux between different P pools are
computed. By coupling the water movement with the
P flux, the model can simulate leaching of P.
Although a description of the water flux is beyond
the scope of this paper, the inorganic P flux will be
briefly described.
Figure 1. Relationship between degree of phosphorus saturation (DPS) and leachate P concentration as
described by Schoumans and Groenendijk (2000): where c is the concentration of P in leachate, and α, β,
and K are constants 0.5, 0.167, and 35, respectively, as determined for a non-calcarous sand.
37
Inorganic P in GLEAMS is divided into three
pools—stable P, active P, and labile P. Plantavailable and mobile P is represented by the labileP pool, which is in a relatively fast equilibrium with
the active-P pool. The stable-P pool represents the
soil P that is slowly available for crop uptake and or
leaching. In highly weathered soils, flux between the
stable- and active-P pools is a function of the
relative size of the pools and the clay content.
The flux between the active- and labile-P pools
is a function of the soil water content, temperature,
clay content, and the relative size of the two pools.
In general, increasing the clay content will decrease
the size of the labile-P pool and increase the sizes
of the active- and stable-P pools. Also, increasing
the clay content will increase the flux from labile to
active and from active to stable pools while
decreasing fluxes in the opposite direction (i.e.,
when labile P is being replenished due to depletion
from crop uptake).
The labile-P pool is fractionated into dissolved P
(available for leaching) and particulate P, as shown
in equations 1 and 2:
Equation 1
Equation 2
Cw = Cs(1/kd)
kd = 100 + 2.5 (%clay)
where Cw is the P concentration in the water (mg
L-1), Cs is the adsorbed P concentration (mg kg-1),
and kd is the partitioning coefficient. As can be seen
in the above equations, the relationship between Cw
and Cs is a straight line with slope of 1 kd-1.
Furthermore, the relationship between labile P and
active P is a straight line as is the relationship
between the active- and stable-P pools.
Boundary
Figure 2. Geographic relationship between swine farms and sandy soils (Arenic Udults, Grosarenic
Udults, and Psamments) in Sampson and Duplin counties in North Carolina.
38
The end result of the these combinations of
equations is a straight-line relationship between
adsorbed-P and solution-P concentrations, as
opposed to the nonlinear relationship typical of Padsorption isotherms (Figure 3). Although this
relationship may be suitable at low soil-P
concentrations, it can potentially underpredict the P
concentrations at high soil-P levels.
Objectives
The objectives of this research are to
i. determine leachate-P concentrations
below an agricultural waste application field,
ii. determine relationships between
leachate-P concentrations and soil chemical
properties, and
iii. validate leachate-P concentrations
predicted with the GLEAMS model.
Methods
Leachate was collected from Blanton (loamy,
siliceous, semiactive, thermic Grossarenic
Paleudults) and Autryville (loamy, siliceous,
subactive, thermic Arenic Paleudults) soils that had
received long-term swine lagoon effluent
applications. Soils were planted in bermudagrass
pasture and grazed with occasional harvest of hay.
Leachate was collected at 45, 90, and 135 cm with
suction lysimeters constructed of modified Nalgene
polysulfone membrane filter holders equipped with
0.45-mm polyethersulfone membranes.
Membranes had a bubble point >200 kPa and,
therefore, would hold a vacuum when moist. A
vacuum of –10 kPa was continuously applied to the
samplers. Samplers were emptied approximately
every two weeks; therefore, each sample is a
composite sample of the leachate collected over the
two-week period. Pastures remained under the
current management practices of grazing and swine
lagoon effluent applications during the sampling
period. Leachate samples were analyzed for
dissolved reactive P with the ascorbic-acid–
molybdate-blue method.
Soil samples were taken at 5- to 15-cm
increments from the surface down to 140 cm in the
vicinity of the lysimeters. These soil samples were
extracted for Mehlich 3 P (M3-P). Future analyses
include total P, total C, total N, and water-soluble P.
Figure 3. Figure 3. Comparison between a Frendlich adsorption isotherm for a Norfolk sandy loam A
horizon and the predictions for leachate P concentration made with the GLEAMS P equations at 15,
50, and 150 days following P application and the predicted equilibrium concentration.
39
Also, intact soil samples were taken for determination
of bulk density, hydraulic conductivity, and moisturerelease curves.
Preliminary Results
P leaching is apparent in both the Autryville and
Blanton soils as is indicated by the elevated M3-P
concentration with depth (Figure 4). The M3-P
concentration in the Blanton soil is between 100 and
150 mg kg-1 M3-P in the upper 100 cm and gradually
decreases below 100 cm. This trend indicates that
the soil is near the P-sorption capacity. The P
distribution in the Autryville soil is very different than
that in the Blanton soil, where it decreases in the
region of the E horizon (20–50 cm), increases
sharply in the B horizon (55–75 cm), and then
decreases to near-background levels thereafter.
Although the clay only increases from 7 to 15% in
the B horizon of the Autryville soil, it has a large
effect on the P-retention capacity of the soil.
Changes in other soil properties, such as increased
Fe content, may accompany the clay increase and
result in increased P-sorption capacity.
From August to mid-November, the P
concentration in the leachate from the Blanton soil
at 45 cm remained between 3 and 7 mg L-1, after
which it increased dramatically to 14–18 mg L-1
(Figure 5). This increase could be due to reduced
plant growth with correspondingly reduced P uptake
or a flush of P released from microbial death due to
colder temperatures. Phosphorus concentration in
leachate at 45 cm in the Autryville soil tended to
decrease from August to December and show a
slight increase afterwards. Although seasonal trends
in leachate P concentrations seem to be apparent in
the shallower depths, more data must be collected
to make accurate conclusions.
Leachate-P concentrations at 90 cm were much
higher in the Blanton soil than in the Autryville soil
(Figures 5, 6). This agrees with the M3-P
distribution in the soil, where the Blanton soil
showed P leaching to depths greater than 100 cm
and the Autryville soil showed a sharp decline in P
leaching at depths greater than 80 cm. These data
support the hypothesis that a small increase in clay
content can have a large impact on P leaching.
Phosphorus concentration in the leachate at 135 cm
deep were below the detection limit (0.028 mg L-1 P)
for both soils (Figure 6).
Leachate P concentrations predicted by GLEAMS
simulations were less than 0.1 mg L-1 P for all depths
(data not shown), indicating that the GLEAMS model
will need some adjustments prior to being used to
predict P leaching.
Figure 4. M3-P distribution with depth in Blanton and Autryville soils with a long-term history of swine
lagoon effluent application. M3-P distribution of a tobacco field is given as a comparison. *Data from
Ham (1999).
40
Figure 5. Leachate P concentrations for leachate collected at 45 and 90 cm in a Blanton soil and 45
cm in an Autryville soil.
Figure 6. Phosphorus concentration in leachate collected at 135 cm in a Blanton soil and 90 and 135
cm in an Autryville soil.
.
41
Preliminary Conclusions
These results show that P leaching can result in
elevated P concentrations in leachate below waste
application fields. However, increases in clay
content to more than 15% increases the capacity of
the soil to hold the P and greatly reduces the P
concentration in the leachate. Further data
collection is necessary to determine the seasonal
fluctuation in leachate P concentrations and
possible effects of changing weather patterns.
Preliminary results indicate that GLEAMS
underpredicts leachate-P concentrations in
situations of high soil-P levels. Improvements in the
GLEAMS algorithms are necessary before
GLEAMS can be used to estimate long-term
impacts of P leaching.
References
Correll, D.L. 1998. The role of phosphorus in the
eutrophication of receiving waters: a review. J.
Environ. Qual. 27:261–266.
Fox, R.L., and E.J. Kamprath. 1971. Adsorption and
leaching of P in acid organic soils and high organic
matter sand. Soil Sci. Soc. Am. Proc. 35:154–155.
Ham, R.J. 1999. Phosphorus movement in poultry,
swine, and tobacco farm soils in the North Carolina
Coastal Plain. M.S. thesis. N.C. State Univ., Raleigh.
Hansen, N.C., T.C. Daniel, A.N. Sharpley, and J.L.
Lemunyon. 2002. The fate and transport of
phosphorus in agricultural systems. J. Soil Water
Conserv. 57:408–417.
Heckrath, G., P.C. Brookes, P.R. Poulton, and
K.W.T. Goulding. 1995. Phosphorus leaching from
soils containing different phosphorus concentrations
in the Broadbank experiment. J. Environ. Qual.
24:904–910.
Marconi, D.J., and P.V. Nelson. 1984. Leaching of
applied phosphorus in container media. Sci. Hortic.
(Canterbury, Engl.) 22:275-285.
McDowell, R.W., and A.N. Sharpley. 2001.
Approximating phosphorus release from soils to
surface runoff and sub-surface drainage. J. Environ.
Qual. 30:508–520.
Mikkelsen, R.L. 1997. Agricultural and environmental
issues in the management of swine waste. p. 110–
119. In J.E. Rechcigl and H.C. MacKinnon (ed.)
Agricultural uses of by-products and wastes. American
Chemical Society, Washington, DC.
North Carolina State University Spatial Information
Research Lab. 2000. North Carolina nutrient
management database project [Online]. Available at
http://www.spatiallab.ncsu.edu/nutman/ (verified 9
Aug. 2001).
Natural Resources Conservation Service (NRCS).
1999a. Nutrient management technical assistance
activities policy; Revision. U.S. Federal Register 64
(74): 19122–19123, 19 April 1999. FR Doc. 999704. Available at http://frwebgate.access.gpo.gov/
cgi-bin/getdoc.cgi?dbname=1999_register&docid
=99-9704-filed (verified 27 Oct. 2003).
Natural Resources Conservation Service (NRCS).
1999b. Conservation practice standard: nutrient
management. Code 590. USDA-NRCS, Raleigh, NC.
Schoumans, O.F., and P. Groenendijk. 2000.
Modeling soil phosphorus levels and phosphorus
leaching from agricultural land in the Netherlands.
J. Environ. Qual. 29:111–116.
Sharpley, A.N. 1995. Dependence of runoff
phosphorus on extractable soil phosphorus. J.
Environ. Qual. 24:920–926.
Sharpley, A.N., T.C. Daniel, J.T. Sims, and D.H.
Pote. 1996. Determining environmentally sound soil
phosphorus levels. J. Soil Water Conserv. 51:160–
166.
Izuno, F.T., C.A. Sanchez, F.J. Coale, A.B. Bottcher,
and D.B. Jones. 1991. Phosphorus concentrations in
drainage water in the Everglades Agricultural Area.
J. Environ. Qual. 20:608–619.
Sims, J.T., R.R. Simard, and B.C. Joern. 1998.
Phosphorus loss in agricultural drainage: Historical
perspective and current research. J. Environ. Qual.
27:277–293.
Leinweber, P., R. Meissner, K.-U. Eckhardt, and J.
Seeger. 1999. Management effects on forms of
phosphorus in soil and leaching losses. Eur. J. Soil
Sci. 50:413–424.
Turner, B.L., and P.M. Haygarth. 2000. Phosphorus
forms and concentrations in leachate under four
grassland soil types. Soil Sci. Soc. Am. J. 64:1090–
1099.
42
Application of Soil Water Budgets to
Landscape Hydrology Analysis
By Gary S. Kreiser, Michael J. Vepraskas, and Rodney L. Huffman
Introduction
Carolina Bays
The N.C. Department of Transportation
(NCDOT) is in the process of a wetland mitigation
project of a drained Carolina Bay in Robeson
County. The project will provide compensatory
wetland mitigation in the Lumber River Basin of
southeastern North Carolina, which will offset
wetland impacts from road construction projects in
the river basin (Hauser, 2001). The site, known as
Juniper Bay, is composed of 750 acres of an
extensively drained Carolina Bay that was used for
agricultural production. The goal of the project is to
restore the functions and values of a Carolina Bay.
N.C. State University is investigating the hydrologic,
soil, and vegetative changes that occur in Juniper
Bay as a result of this restoration project.
The success of a restoration project is
dependent on meeting three criteria necessary for a
jurisdictional wetland: wetland hydrology, hydric
soils, and hydrophytic plants. Wetland hydrology
requires saturation of the soil at or near the surface
for at least 12% of the growing season. Hydric soils
are soils that have been saturated long enough to
develop anaerobic conditions. Hydrophytic
vegetation are plants that are adapted to saturated
and anaerobic soils. Of the three criteria, wetland
hydrology is the most important. Without the proper
wetland hydrology, conditions favorable for hydric
soils and hydrophytic vegetation will not be met and
the restoration project will not be successful.
The objectives of this research are to establish
a water budget, compute the magnitude of water
inflow and outflow into the bay, and discuss possible
implications of the restoration impact.
Carolina Bays are oval-shaped depressions of
unknown origin that lie in a northwest to southeast
orientation (Johnson, 1942). An estimated 500,000
bays are found along the Atlantic Coastal Plain from
Maryland to northern Florida (Knight et. al., 1985).
The maximum concentration of bays occurs in
southeastern North Carolina and northeastern South
Carolina, where the bays may account for more than
50% of the ground surface (May and Warne, 1999).
There have been numerous studies on Carolina
Bays in order to determine their origin. To this day,
there has been no universally accepted theory, and
the debate still continues.
Hydrology is the most important variable in the
creation and maintenance of different types of
wetlands and wetland processes (Mitsch and
Gosselink, 1993). For the classification,
assessment, and restoration of wetlands, there
increasingly is a need to know the sources of water
as well as their amounts and timing (Owen, 1995).
Even though hydrology is known to be important, it
is often overlooked and the least understood aspect
of wetlands. This may be due to the fact that
measuring hydrology is a complex and timeconsuming process.
Hydrologic studies must be well planned to
quantify the temporal and spatial distribution of
water and must consider all possible inputs and
outputs into a wetland. This process for accounting
for all of the water sources and sinks within a
defined site is commonly called a water budget
(Roig, 2000). Water-budget equations are often
used in detailed hydrologic assessment of wetlands
Gary S. Kreiser, Graduate Student, NCSU Soil Science Dept., Raleigh, NC
Michael J. Vepraskas, Professor, NCSU Soil Science Dept., Raleigh, NC
Rodney L. Huffman, Associate Professor, NCSU Biological & Agricultural Engineering Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
43
(Rykiel, 1984; Hyatt and Brook, 1984). Water
budgets are also useful for the calculation of nutrient
budgets. In addition, they can be used to estimate
unknown hydrologic components such as
groundwater flow and predict the effects of natural
and anthological changes on water inputs and
outputs (Carter, 1986; Roig, 2000).
The general components of a water-budget
equation showing the water storage, inflows, and
outflows of a wetland as shown by Mitsch and
Gosselink (1993) may be expressed as
ÄV/Ät = Pn + Si + Gi – ET – So – Go ± T
[1]
where
ÄV/Ät = change in volume of water storage in
wetland per unit time, t
Pn = net precipitation
Si = surface inflows, including flooding streams
Gi = groundwater inflows
ET = evapotranspiration
So = surface outflows
Go = groundwater outflows
T = tidal inflow or outflow
All variables may not occur in all wetlands. There are
many different forms of this equation, all of which are
essentially the same (Carter et. al., 1978; Roig, 2000).
For most hydrologic studies, it is desirable to
measure or estimate all of the components when
calculating a water budget (Dooge, 1972; Hyatt and
Brook, 1984; Carter, 1986). However, this is not
always possible due to the difficulties in making
hydrologic measurements, and one component is
calculated as the residual of the water-budget
equation.
The inherent problem with the residual
component is that it contains the sum of all errors
from the other terms in the budget. These errors can
have a significant effect on the calculations of a
water budget. However, error analysis is not
commonly used, and the residual term is given a
great deal of interpretation and importance, even
though it has little meaning. Winter (1981)
recommends that any hydrologic budget, however
derived, include error analysis to allow for realistic
use of water budgets. By including error analysis,
Equation 1 becomes
ÄV/Ät = Inputs – Outputs ± error
[2]
The inputs and outputs are the same as in Equation 1.
Error is calculated from the standard deviations of
measurement and the known instrument error and
then is summed up in the final water-budget
equation (Owen, 1995).
Methods and Materials
Juniper Bay is located approximately ten miles
southeast of Lumberton, NC, and is 750 acres in
size. The components of the water budget that were
either measured or estimated included precipitation,
evapotranspiration, change in storage, surface
outflow, and groundwater. There was no surface
inflow into the bay.
The hydrology of Juniper Bay was determined
based on the water-budget equation of Inputs –
Outputs = Change in storage. All components
except groundwater were measured to get monthly
totals. Precipitation was measured with tippingbucket rain gauges. Evapotranspiration was
estimated by the Penman–Monteith equation with
data collected by weather station at Juniper Bay.
Change in storage was estimated by taking the
difference in the change in water-table levels in the
bay and multiplying it by the drainable porosity.
Surface outflow was estimated by use of dual
compound weirs located at the main outflow point.
Groundwater was estimated as the residual of
the water-budget equation. Based on the waterbudget equation, groundwater was calculated where
Inputs – Outputs = ÄStorage
ÄStorage = (Precip + Gi) – (ET + Go + So)
Precip + Gi = ET + Go +So + ÄStorage
Gi – Go = ET + So + ÄStorage – Precip
The groundwater component of the water budget is
the net groundwater movement in the bay, and it
was estimated for each month.
Results and Discussion
A water budget for Juniper Bay was estimated
for February 2002 to February 2003. Table 1 lists all
the components of the water budget and their
monthly totals. As seen in Table 1, precipitation and
evapotranspiration are the major input and output
into Juniper Bay. Also note, that the groundwater is
quite a large component at Juniper Bay.
Groundwater
The net groundwater was calculated as being
543 mm for this year. Months that had a positive net
groundwater component represent when Juniper
Bay was acting as a discharge wetland. This means
that more groundwater was entering the bay than
leaving and the excess groundwater was leaving as
surface outflow. When the groundwater component
44
Table 1. Monthly totals for all water budget components
Month
Feb
March
April
May
June
July
August
Sept
Oct
Nov
Dec
Jan
Feb
Total
Change in
Storage (mm)
ET
(mm)
So
(mm)
Precip
(mm)
Gi-Go
(mm)
-9.52
12.89
-60.38
-12.25
-9.42
-12.17
87.26
-55.19
43.60
3.55
16.89
-35.70
36.50
23.10
32.70
58.80
93.00
164.00
169.00
133.00
66.64
29.86
18.91
17.14
19.93
18.43
32.00
60.00
44.50
22.20
3.40
0.06
4.90
19.30
97.38
239.74
59.71
43.10
80.33
52.96
106.17
39.54
43.05
70.10
59.94
171.07
33.91
147.20
79.12
83.30
25.02
103.13
-7.38
-0.58
3.38
59.90
87.88
96.95
54.09
-3.16
23.64
183.08
10.43
2.31
32.13
6.06
844.50
706.60
1014.51
542.65
was negative, more groundwater was leaving the
bay than entering and Juniper Bay was acting as a
recharge wetland. Most of the year Juniper Bay had
a positive net groundwater movement and was
acting in a discharge situation. The net groundwater
component accounts for 35% of the total water
inputs into Juniper Bay. The groundwater
component is large and indicates that Juniper Bay
has a significant groundwater input.
Error Analysis
All components in the water budget that were
measured do contain errors that are propagated
through the water-budget equation and are
contained within the residual term—in this case,
groundwater. Significant errors in interpretation can
occur if the residual term is used without respect to
errors that are inherent to it. Table 2 lists all the
associated errors for each component and their
range.
Errors were taken from the literature (Winter,
1981; Owen, 1995). All the errors combined equal to
171 mm. If all the errors are either additive or
subtractive, the range for groundwater is 371 mm to
713 mm. Even with all the errors associated with
using the residual, the groundwater component is
still positive indicating net groundwater movement
into Juniper Bay.
The ET calculation has by far the largest
potential for error and could have the biggest effect
on our estimate of groundwater input. Based on that
consideration, ET was calculated with different
percent error and graphed with the assumption that
all other components remained the same. Figure 1
shows that if ET calculations were off by 50%, there
would still be a net-positive groundwater component
of 137 mm for the year.
Groundwater Flow into Juniper Bay
After one considers all of the errors associated
with the water budget, even in the worst-case
situation of being off by 50% in the ET calculation,
there still is a net-positive groundwater component.
This raises the question of where the groundwater
comes from. To determine the possible source areas
of groundwater, one must look at the topography of
Juniper Bay and the surrounding area.
Figure 2 shows that Juniper Bay is about 36 m
above sea level. Uplands occur to the east and west
of Juniper Bay with elevations of about 38 to 40 m.
45
Table 2. Water budget components and associated error.
Component
Estimate (mm)
% Error
Error (mm)
Range (mm)
Precip
1014
5
± 50.7
963–1065
Change in Storage
6.1
5
± 0.305
5.8–6.4
Surface Outflow
707
5
± 35.4
672–742
ET
845
10
± 84.5
761–930
25
± 171
Total error
600
542
550
500
450
Gi-Go
400
350
300
250
200
150
137.3
100
50
0
50
55
60
65
70
75
80
85
90
95
100
ET( %P ET)
Figure 1. Evapotranspiration (ET) as a fraction of potential evapotranspiration (PET). Estimates of ET
are needed to compute water budget, but PET was estimated from meteorological data. The expected
range of ET is shown.
Figure 2. Map of Juniper Bay and surrounding area-showing elevation in meters above sea level.
Higher elevations to east and west and lower elevations to north and south.
46
Lowlands occur to the south and north of Juniper
Bay with elevations around 34 m. These differences
in elevation create a hydraulic gradient that might
account for possible groundwater inputs into the
bay. The higher elevations or uplands are possible
sources for groundwater inputs, and the lower
elevations are possible sources for groundwater
outputs.
It is thought that the stratigraphy of Juniper Bay
is such that there are multiple aquifers below the
bay. Throughout Juniper Bay there is a
discontinuous clay layer that is acting as an
aquitard. However, in areas where there are breaks
in the clay, it is possible there is groundwater
upwelling.
Figure 3 shows a schematic diagram of Juniper
Bay with the possible sources of groundwater input.
Aquifer 1 is the shallow subsurface region that is
above the clay layer. It is thought that the shallow
groundwater from the adjacent uplands is entering
into the bay and being intercepted as surface
outflow by the perimeter ditch.
Aquifer 2 is the area below the clay layer and is
contained by the Black Creek Formation. It is
thought that the more distant groundwater is moving
through Aquifer 2. The clay breaks in Juniper Bay
are thought to be possible areas where there is deep
groundwater from Aquifer 2 coming up into the bay.
Implications
The water-budget analysis reveals that Juniper
Bay is acting as a discharge wetland, with
groundwater entering the bay and leaving as
surface outflow. Topographically, Juniper Bay lies at
an intermediate elevation. In a natural setting, it
should be acting as a flow-through wetland.
There are two possible scenarios for the effect
groundwater will have on restoration. If the main
ditch is plugged with the perimeter ditched left
open, then wetland hydrology can be restored, and
the excess water will be taken away as surface
outflow (Figure 4). However, if the perimeter ditch is
closed, then there will be no outlet for the
groundwater, and the water levels might rise above
the present soil surface (Figure 5).
In the second scenario, water levels may rise
because it has been estimated that the subsidence
of organic soils could be as great as 80 cm (Ewing,
2003)—which means that the soil surface at Juniper
Bay was, at one time, higher. Restoration of Juniper
Bay with the perimeter ditch closed could raise the
water table above the surface and might also cause
groundwater outflow, which might raise the water
table in the surrounding area. Such instances of
hydrological trespass could be a potential problem
for the restoration project.
Black Creek-Regional Aquitard
Figure 3. Schematic diagram of Juniper Bay showing discontinuous clay layer and possible aquifer.
Arrows indicate possible groundwater movement into Juniper Bay.
47
Figure 4. Schematic diagram representing scenario after restoration with perimeter ditch left open.
Arrows represent groundwater inflow.
Figure 5. Schematic diagram representing scenario after restoration if perimeter ditch closes. Arrows
indicate groundwater movement. Groundwater flows offsite through Aquifer 1.
48
Conclusion
This study used a water budget to determine the
potential of restoring a drained Carolina Bay into a
wetland. Measured components of the water budget
included precipitation, ET, surface outflow, and
change in storage. Groundwater was estimated as
the residual from the water-budget equation.
A water budget for Juniper Bay was estimated
during 2002–2003. These findings indicate that
Juniper Bay has a significant groundwater
component and that this groundwater inflow could
possibly influence the restoration project.
Two possible scenarios upon restoration of
Juniper Bay must be evaluated in light of this
information. In Scenario 1, the main ditch is plugged
while the perimeter ditch would remain open. Under
this scenario, wetland restoration would occur, and
the perimeter ditch would intercept the excess
groundwater.
In Scenario 2, the perimeter ditch would be
closed resulting in groundwater entering the bay and
possibly raising the water table about the soil
surface. This excess water might cause groundwater
outflow into the lower surrounding areas. The
movement of groundwater outflow into neighboring
areas could possibly cause hydrologic trespass.
Upon restoration, it appears that Juniper Bay
will function as a flow-through wetland. Groundwater
will enter the bay and then will leave as groundwater
outflow. Our findings indicate the restoration project
must take into account the groundwater component
of the site.
References
Carter, V. 1986. An overview of the hydrologic
concerns related to wetlands in the United States.
Can. J. Bot. 64:364–374.
Carter, V., M.S. Bedinger, R.P. Novitzki, and W.O.
Wilen. 1978. Water resources and wetlands. p. 344–
376. In P.E. Greeson et al. (ed.) Wetland functions
and values: the state of our understanding. Am.
Water Resour. Assoc., Minneapolis, MN.
Dooge, J. 1972. The water balance of bogs and fens
(review report). p. 233–271. In Hydrology of marshridden areas. Proc. Minsk Symp., 1972. UNESCO
Press, Paris.
Ewing, J.M. 2003. Characterization of soils in a
drained Carolina Bay wetland prior to restoration.
Ph.D. diss. North Carolina State University, Raleigh.
(Available online at http://www.lib.ncsu.edu/theses/
available/etd-10162003-142921/.) (Verified 21 Nov
2003.)
Hauser, J. 2001. NCDOT develops Juniper Bay
mitigation site. Centerline (an environmental news
quarterly from NCDOT Natural Systems Unit)
January 2001, Issue No. 4: 1.
Hyatt, R.A., and G.A. Brook. 1984. Ground water
flow in the Okefenokee Swamp and the hydrologic
and nutrient budgets for the period August 1981
through July 1982. p. 229–245. In A.D. Cohen et al.
(ed.) The Okefenokee Swamp. Wetland Surveys,
Los Alamos, NM.
Johnson, D.W. 1942. The origin of the Carolina
bays. Columbia University Press, New York.
Knight, R.L., B.H. Winchestor, and J.C. Higman.
1985. Carolina bays—feasibility for effluent
advanced treatment and disposal. Wetlands 4: 177–
203.
May, J.H., and A.G. Warne. 1999. Hydrogeologic
and geochemical factors required for the
development of Carolina bays along the Atlantic and
Gulf of Mexico Coastal Plain, USA. Environ. Eng.
Geosci. 5(3): 261–270.
Mitsch, W.J., and J.G. Gosselink. 1993. Wetlands.
2nd ed. Van Nostrand Reinhold, New York.
Owen, C.R. 1995. Water budget and flow patterns in
an urban wetland. J. Hydrol. 169:171–187.
Roig, L.C. 2000. Determining existing hydrologic
conditions. p. 2–46. In Wetlands engineering
handbook. U.S. Army Corps of Engineers,
Washington, DC.
Rykiel, E.J., Jr. 1984. General hydrology and
mineral budgets for Okefenokee Swamp. p 212–
228. In A.D. Cohen et al. (ed.) The Okefenokee
Swamp. Wetland Surveys, Los Alamos, NM.
Winter, T.C. 1981. Uncertainties in estimating the
water balance of lakes. Water Resour. Bull. 17:82–
115.
49
Modeling Construction Site Impacts on Watersheds
By Amber D. Moore, Rich A. McLaughlin, and Helena Mitasova
Introduction
Sediment from erosion processes is considered
to be the most widespread pollutant in streams
today. Unfortunately, it is also one of the most
difficult pollutants to control because many
industries depend on the movement and exposure
of soil. Construction practices would be obsolete
without manipulation of the soil surface.
Soil erosion can be greatly reduced by
controlling raindrop, sheet, and rill erosion (Beasley,
1972). Vegetation can control erosion losses by
forming a barrier to rainfall impact, slowing flow
velocities by increasing surface roughness, and
holding the soil in place with plant roots. Removal of
vegetation during construction increases
concentration of sediment in streams.
Large sediment loads can clog channels,
destroy suitable aquatic habitats, and reduce
reservoir storage. Land developers depend on
sediment and erosion controls—such as sediment
basins, vegetated stream buffers, and silt fences—
to retain sediment on construction sites. Undersized
basins, poor placement of silt fences, ineffective
stream buffers, and other similar problems often
occur during the design of sediment and erosion
control plans, greatly reducing the effectiveness of
the erosion controls.
Models may be used to predict the movement
of water and sediment on watersheds, allowing
developers to optimize the effectiveness of
sediment controls before they are installed. Erosion
prediction models can provide information on a
various number of scenarios without labor-intensive
field studies and have been used to predict effects
based on changes in land use (Rodda et al., 2001).
The objectives of this study are 1) to calibrate
the WEPP model by comparing our predicted results
to field data, 2) to predict the impact of land cover
during and after construction, and 3) to evaluate the
effectiveness of stream buffers as sediment controls
through the use of computer models.
Materials and Methods
SITE DESCRIPTION
A watershed within N.C. State University’s future
Centennial Campus golf course in Raleigh, NC, was
used for monitoring and modeling. The 27-acre
watershed drains from a well-vegetated area (Table
1) into a first-order intermittent channel. The site
elevation ranges from 317 to 417 feet above sea
level and receives an average rainfall of 41 inches
per year.
SAMPLING PROCEDURE
Flow measurements and samples were
extracted from the watershed stream outlet. A Vnotch weir was placed in the stream outlet for flow
measurements, which were taken in 1-minute
intervals with an ISCO 730 Flow Bubbler Module.
For sediment-load estimation, four sample events
were composited into each of 24 1000-ml bottles
through use of the ISCO 6712 Sampler. The
sampler was triggered to retrieve samples based on
a specific flow rate.
Samples were analyzed for turbidity with an
Analite 152 Nephlometer Probe. Turbidity values
were used to estimate total suspended solids (TSS)
based on a previously established relationship
between the two variables for that site. Flow rates
and TSS data were compiled to estimate sediment
A.D. Moore, Graduate Student, NCSU Soil Science Dept., Raleigh, NC
R.A. McLaughlin, Associate Professor, NCSU Soil Science Dept., Raleigh, NC
H. Mitasova, Associate Adjunct Professor, NCSU Marine, Earth, and Atmospheric Sciences Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
50
simulated with the Water Erosion Prediction Project
(WEPP) model, a one-dimensional, process-based
model that applies input parameters based on the
Universal Soil Loss Equation (Flanagan and
Nearing, 1995). GIS data layers were imported into
WEPP with GeoWEPP. GeoWEPP is a program
that allows WEPP simulations based on GIS data
layers (Renschler, 2003).
A storm event that delivered 4.0 inches of rain
to the site on 11 Oct. 2002 was used for model
simulations (Figure 2). This event was selected due
to similar rainfall patterns to a two-year return period
for Raleigh (3.5 inches in a 24-hour period), which
most sediment and erosion control plans are
designed to handle.
yield from the watershed. Rainfall data were
retrieved from an ISCO 674 Tipping Bucket Rain
Gauge placed in an adjacent watershed.
MODEL APPLICATION
Topographic data layers were constructed and
manipulated with ArcView GIS 3.2a and GRASS
5.0. Soils information, scaled at 1:24,000, was
downloaded from the National SSURGO Database.
The initial landcover map was extrapolated from
aerial photos of the site. Design plans for the golf
course layout from the Palmer Group were used to
produce GIS data for the other land-cover scenarios
(Figure 1).
The original digital elevation model was created
by converting contour topographic maps to a grid
format using a D-infinity spline algorithm. For
modeling purposes, all data layers were converted
to 6m-cell-size ASCII raster files, projected in zone
17N UTM. Erosion processes on the site were
Results and Discussion
Predicted runoff volume from the watershed was
eight times greater than the actual discharge, while
Table 1. Watershed landcover percentages.
Scenario
Land cover percent
Forest
Tall grass
Golf course
grass
Sand
traps
Impermeable
surfaces
Exposed
soil
Water
Initial Conditions
(measured)*
58
40
—
—
1
—
1
Initial Conditions
58
40
—
—
1
—
1
Construction,
with 50-foot
forested buffers
(Based on
developer’s
design plans)
10
15
—
—
1
73
1
Construction,
with 25-foot
forested and
25-foot grass
buffers
6
19
—
—
1
73
1
Construction,
with no buffers
—
22
—
—
1
76
1
Final golf
course
10
15
70
2
1
—
1
51
Figure 1. Rainfall event used for erosion prediction, which occurred on 10/11/02 at the watershed site.
Figure 2. Landcover for the final golf course.
52
Table 2. Runoff volumes and soil loss estimates for the entire watershed as predicted by WEPP.
Scenario
Runoff volume
volume (m3)
Soil loss
(tonne)
Initial Conditions (measured)*
537
0.34
Initial Conditions
4230
23
Construction, with 50 ft forested buffers
4890
280
Construction,
with 25-foot forested and 25-foot grass buffers
8270
370
Construction, with no buffers
8340
390
Final golf course
4770
15
predicted soil loss was 68 times greater than the
actual sediment yield (Table 2, Figure 3-a).
Eventually we hope to determine discharge and
sediment yield values from the model, making the
comparison between measured and modeled
conditions more reasonable. Although we are not yet
able to predict discharge and sediment yield from
this site using WEPP, we can still make
comparisons between landcover scenarios to
evaluate erosion control effectiveness.
Based on predicted WEPP values, soil loss
increased 12-fold during construction conditions with
the forested buffers created by the golf course
designers, while runoff volume only increased by
16% (Table 2). Sediment loss could be greatly
reduced by extending the buffer to entire extent of
the stream, since the greatest erosion occurs in the
areas surrounding nonbuffered stream reaches
(Figure 3-d). The use of the forested buffers during
construction did decrease sediment loss by 28%,
showing that they were somewhat effective for
reducing soil loss (Table 2, Figure 3-b).
The replacement of the outer 25 feet of forested
buffer with grass buffer increased runoff volume by
96% and soil loss by 16-fold, as compared to initial
forested conditions (Table 2, Figure 3-c). It is likely
that the model predicts greater infiltration and
rainfall interception from leave cover for trees than
for grass, explaining the increased runoff rates.
However, research has shown that the use of grass
and/or forest buffers decreases soil loss (Lowrance
et al., 1995), indicating that a specific category for
riparian buffer grass should be added to the model
so there is an option other than the “Bromegrasstall” category from the WEPP land management
menu.
Conclusions
From this study, we can conclude that WEPP
and GeoWEPP are useful tools for reducing
sediment losses from construction sites that allow
the user to manipulate land-management scenarios
to produce the least amount of soil loss.
Comparisons between measured and modeled
sediment yield predictions of sites during and after
construction need to be made to validate predictions
made by the WEPP model.
References
Beasley, R.P. 1972. Erosion and sediment pollution
control. The Iowa State University Press, Ames, IA.
Flanagan, D.C., and M.A. Nearing (ed.). 1995.
USDA-Water Erosion Prediction project: hillslope
profile and watershed model documentation. NSERL
Rep. No. 10. USDA-ARS National Soil Erosion
Research Laboratory, West Lafayette, IN.
Lowrance, R.L., L.S. Altier, J.D. Newbold, R.R.
Schnabel, P.M. Groffman, J.M. Denver, D.L. Correll,
J.W. Gilliam, J.L. Robinson, R.B. Brinsfield, K.W.
Staver, W. Lucas, and A.H. Todd. 1995. Water
quality functions of riparian forest buffer systems in
53
the Chesapeake Bay Watershed. USEPA Rep. 903R-95-004/CBP/TRS 134/95. U.S. Gov. Print. Office,
Washington, DC.
Rodda, H.J.E., M.J. Stroud, U. Shankar, and B.S.
Thorrold. 2001. A GIS based approach to modeling
the effects of land-use change on soil erosion in
New Zealand. Soil Use Manage. 17:30–40.
Renschler, C.S. 2003. Designing geo-spatial
interfaces to scale process models: the GeoWEPP
approach. Hydrol. Process. 17:1005–1017.
Figure 3. Deposition and erosion patterns during test rainfall event: a) Initial conditions, b) Construction
with no buffers, c) Construction with 25-foot forested and 25-foot grass buffers, d) Construction with
50-foot forested buffers, e) Final established golf course.
54
Field Assessment of Water Flow
from Trenches of Septic Systems
By Aziz Amoozegar, Christopher P. Niewoehner, and David Lindbo
Introduction
For approximately 50% of the housing units in
North Carolina, domestic sewage is commonly
managed on-site by septic systems. The most
common type of septic system is a conventional, or
gravity-fed, system. In general, a conventional
system is composed of a septic tank (also known as
interceptor tank) and a drainfield (also known as
leachfield and nitrification field) (Figure 1A).
The septic tank is a relatively large container
(tank) where sewage from the respective dwelling
enters and receives primary treatment before being
applied to the drainfield. The drainfield, in most
cases, is composed of a series of trenches that are
dug into the soil and are connected in parallel or in
series. The trenches of conventional septic systems
in North Carolina are typically 90 cm (3 feet) wide
and 90 cm (3 feet) deep with 270-cm (9-foot)
spacing between the centerline of the trenches. For
parallel trenches, wastewater is distributed to all the
trenches through a distribution box or another
distribution mechanism (Figure 1A). For a properly
designed septic system, the soil in the drainfield
area treats wastewater and renders it harmless
before it enters ground or surface water resources.
Not all the soils and locations are suitable for
conventional septic systems. Other technologies—
such as low-pressure pipe (LPP) distribution
(Cogger et al., 1982) and drip systems (Oron et al.,
1991)—can be used for areas where the soils have
some type of limitations for a conventional system.
The basic components of LPP (also drip) systems
are a septic tank, a pump tank (reservoir), and a
drainfield (Figure 1B). The drainfield of a typical
LPP system in North Carolina is composed of a
series of trenches with a perforated PVC pipe
installed in a gravel bed in each trench. The width of
the trenches is generally between 20 and 30 cm (8
to 12 inches); the depth of trenches varies with soil
and location; and the spacing between the centerline
of the neighboring trenches is 150 cm (5 feet). In
these systems, wastewater from the septic tank is
stored in the pump tank before being intermittently
applied to the drainfield.
For a septic system to function properly, all the
wastewater applied to the drainfield of the system
must infiltrate the soil and move away from the
drainfield area without surfacing. Water applied to
the trenches in a septic system can enter the soil
through the bottom and sidewalls (up to the level of
wastewater) of each trench. Since soils are
heterogeneous and anisotropic, wastewater
infiltration and water flow away from the trenches of
a septic system are not symmetrical and may occur
through macropores and special features in the soil
(Vepraskas et al., 1991). Furthermore, movement of
wastewater away from the trenches is related to the
depth of the trenches, position of the drainfield on
the landscape, as well as depth to an impermeable
layer or water table below the bottom of the
trenches. On sloping grounds, lateral movement of
water from upper trenches may have an impact on
the infiltration of wastewater from the lower trenches
and lateral movement of wastewater from the area.
The goal of this study was to assess water
movement from a series of parallel trenches
installed in three different soils.
MATERIALS AND METHODS
Four separate experiments were conducted at
three sites with different soils to assess the
movement of water and dissolved solutes from
trenches installed on contour lines on a side slope.
Aziz Amoozegar, Professor, NCSU Soil Science Dept., Raleigh, NC
Christopher P. Niewoehner, Agricultural Research Technician II, NCSU Soil Science Dept., Raleigh, NC
David Lindbo, Assistant Professor, NCSU Soil Science Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
55
Figure 1. Schematic diagram of the areal view of conventional septic system (A) and low-pressure
pipe distribution system (B) showing the septic tank, the pump tank, and the drainlines in the drainfield
area of each system.
The sites were located on the N.C. State University
Field Research Laboratory in Clayton and at the
Reedy Creek and Lake Wheeler Stations in Raleigh.
At the Clayton and Lake Wheeler sites, a 10-m2
area and an 8-m2 area, respectively, were selected
for conducting the experiment. At the Reedy Creek
site, two 8-m2 areas were delineated for two
separate experiments.
The soils in the general area at the Clayton site
had been mapped as Appling sandy clay loam, with
6 to 10% slope (Kleiss et al., 1981). The soil at the
study area was composed of a coarse-textured
topsoil with a clayey subsoil. The soils in the general
area at the Reedy Creek site had been mapped as
Appling gravelly sandy loam and Appling sandy
loam with 10–15% slope (Cawthorn, 1970). Two
shallow pits were dug in the area to determine the
depth and the thickness of the Bt horizon. At this
site, the soil had a 36-cm thick A/E horizon underlain
by a clayey Bt horizon. The soil at the Lake Wheeler
site had been mapped as Appling sandy loam with 6–
10% slope and as Wedowee sandy loam with 15–25%
slope (Cawthorn et al., 1970).
At each site, a series of soil samples from
various depths and locations was collected for
particle size analysis by the pipet method (Gee and
Bauder, 1986). Saturated hydraulic conductivity
(Ksat) of various depth intervals was determined in
situ by the constant-head well permeameter
technique (Amoozegar and Wilson, 1999) and use
of the Compact Constant Head Permeameter
(Amoozegar, 1992). Selected characteristics of the
soils in the study areas are presented in Table 1.
To simulate an LPP system, we installed four
parallel trenches—4.5 m (15 feet) long, 30 cm wide,
and 30 cm deep—on the contour lines at a linear
landscape position (Daniels et al., 1999) at the
Clayton site. The distance between the trenches was
150 cm, and the elevation difference between the
neighboring trenches was approximately 15 cm (the
slope of the land in the study area was 10%). The
relative positions of the trenches are shown in
Figure 2.
At the Reedy Creek site, two sets of
experiments were conducted. In the first, four
parallel trenches—4.5 m long, 30 cm wide, and 40
cm deep—were dug into the Bt horizon. In the
second, the four drainline trenches were dug in the
upper part of the soil such that the bottom of the
trenches was above the clayey Bt horizon.
56
Table 1. Selected properties of the soil at the study sites.
Site
Sand
Clay
- - - - - - -% - - - - - -
Ksat (cm d-1)
Depth (cm)
Horizon
Clayton
0-30
30-47
47-80
80-100
A
E
Bt
B/C
80
70
24
29
5
7
65
53
19.2
ND
7.2
ND
Reedy Creek
0-25
25-36
36-85
85-114
105-120
A
E
Bt
B/C
—
74
78
18
38
—
8
10
68
43
—
19.2
ND
4.8
ND
2.9
Lake Wheeler
0-15
15-21
21-68
68+
A
E
Bt
C
57
58
38
71
22
22
49
10
ND
ND
4.8
ND
Figure 2. Schematic diagram of the areal view of the field trench experiment at the study sites
showing the relative locations of the trenches. Also shown is the position of the observation/sampling
pit dug perpendicular to middle of the drainlines (trenches).
57
At the Lake Wheeler site, four trenches—4.5 m
long, 30 cm wide, and 45 cm deep—were dug on
contour on the side slope for installing the
drainlines. The distance between the center lines of
the neighboring trenches was 150 cm (5 feet) for all
the experimental systems. These LPP systems were
constructed by digging the trenches with a small
backhoe. After most of the loose soil was removed
from the bottom of the trenches at each site, a
section of a 1-inch PVC pipe—with five 1/8-inch
holes drilled at approximately 45, 135, 225, 315, and
405 cm from the end of the pipe with a turn up—was
placed in a section of 4-inch corrugated drainage
pipe installed inside a 20-cm thick gravel envelope
in each trench. The gravel selected for the study
was similar to the gravel commonly used for septic
systems in the Piedmont region. To prevent
migration of soil particles into the gravel envelop,
the gravel in each trench was covered with a layer
of newspaper, and the trench was back filled with
soil that was removed during its construction.
Hereafter, these trenches will be referred to as
drainlines.
Water or tracer solution was applied to each
drainline by attachment of an individual dosing
system to the open end of the PVC pipe in each of
the four trenches. A portable reservoir, placed above
the study area, supplied water and tracing solution
to each dosing device.
With the use of a timer, a total of 50 L of well
water from the Clayton Station was applied through
a dosing device to each drainline at this site once a
day (in one dose) for 74 consecutive days. After the
74-day applications of water, 50 L of a solution
containing 5 mmol L-1 (645 mg L-1) potassium
bromide (KBr) and 500 mg L-1 Brilliant Blue FCF
(Erioglaucine) as tracers were applied to each
drainline once a day for 15 days. The amount of
water or solution applied to the trenches was
equivalent to an areal loading rate of 7.16 L m-2 d-1
[equivalent to approximately 0.18 gallon per square
foot per day] for a comparable LPP system.
For the first experiment at the Reedy Creek site,
50 L of tap water from the City of Raleigh was applied
once a day to each trench for 27 consecutive days (a
total of 1350 L per trench). Immediately after water
application, a solution containing 5 mmol L-1 KBr and
500 mg L-1 Brilliant Blue FCF (Erioglaucine) was
applied at the same rate of 50 L d-1, once a day, for 14
days (a total of 700 L per trench). For the second
experiment, 50 L of water was applied once a day to
each trench for 30 days, followed by the application of
50 L of the tracer solution (containing Br and dye) for
an additional 14 days.
At the Lake Wheeler site, 50 L of water was
applied once a day to each trench for 17 days, and
50 L of the tracer solution was applied daily for 14
days (a total of 700 L per trench). Similar to Clayton
site, the amount of water or solution applied to the
trenches of these systems was equivalent to an
areal loading rate of 7.16 L m-2 d-1. All the water and
tracer solution applied daily to the drainlines
infiltrated the soil, and the system was allowed to
drain between the dosing cycles.
At the termination of tracer solution application,
a 1-m wide and more than 120-cm deep pit was dug
perpendicular to the middle part of the four
drainlines at each site. The relative position of this
sampling pit is shown in Figure 2. The walls on both
sides of each pit were photographed and the stained
areas on the walls (around and between the
drainlines) were inspected visually. Soil samples
were then collected from both sides and below each
of the drainlines on a 15-cm2 grid. These samples
were transported to the laboratory, extracted with
water, and analyzed for Br by the flow injection
analysis procedure (Lachat QuickChem Method No.
10-135-21-2-A), which is an adaptation of the
method described by Greenberg et al. (1992).
A mass balance was conducted for each site to
estimate how much Br was retained by the soil
volume around each trench. For this, we assumed
that the soil had a dry bulk density of 1.35 g cm-3
and that the Br distribution in the drainfield was
reflected by the amount found in individual samples
from the grids around the trenches. Based on these
assumptions, the total mass of Br detected at the
termination of the experiment around each trench
was compared with the amount of Br that was
applied to each trench in the drainfield.
RESULTS AND DISCUSSION
Due to the large volume of data for each site,
only the results for the two experiments at the
Reedy Creek site will be presented in detail.
Comparable results were obtained for the other two
sites.
For the first experiment at the Reedy Creek site,
the trenches were dug into the Bt horizon. The
pattern of dye distribution on the two walls of the pit
for this experiment indicated that the dyed-stained
areas were limited to the immediate vicinity of each
trench and that the majority of water flow through
the Bt horizon of this soil was through tubular and
planar voids. For the second experiment, where the
trenches were in the layers above the Bt horizon, on
the other hand, a relatively large volume of the
coarse-textured soil around the trenches was stained
to a limited extent in the Bt horizon. As examples,
photographs showing the stained areas around the
58
second lateral line on the left transect in the first
experiment and the third lateral line on the left
transect in the second experiment are presented in
Figure 3. Note the lack of stained areas in the
vicinity of the trench and scattered stained areas in
the Bt horizon in the first experiment (Figure 3A).
Note the lack of stained areas in the Bt with a
greater movement of the dye solution in the
horizontal as opposed to the vertical direction for the
second experiment where the trenches were placed
above the clayey Bt horizon (Figure 3B).
For the first experiment where trenches were
installed in the Bt horizon, Br concentrations greater
than 100 mg kg-1 were observed mainly below the
trenches and at some isolated locations away from
the trenches on both transects. These isolated, highconcentration locations indicate preferential
movement of the solution applied from the trenches
through the Bt horizon. Although there were more
areas on the left transect (data not shown) that had
little to no Br as compared to the right transect
(Figure 4), Br was detected in a majority of grids
around each of the four transects. On the right
transect, more Br was detected at deeper depths
than on the left transect. The pattern of Br
distribution indicated that water moved diagonally
toward the down-slope side of the site with Br being
detected at more than 150 cm from the trenches. As
was indicated before, the dyed-stained areas for the
first experiment were mainly around the trenches
and large tubular pores, indicating preferential
movement. The lack of Br distribution uniformity
around the trenches (Figure 4) also indicates that
water moves through the well-structured Bt horizon
of this soil mainly through planar and tubular
macropores rather than through the soil matrix.
Although the soil has a clayey texture, it
appears that most of the solution applied to the
trenches moved into and through the Bt horizon.
The mass balance analysis that was conducted for
individual trenches indicated that more than 90% of
the applied Br in this experiment was found in the Bt
horizon.
For the second experiment installed above the
Bt horizon, the solution moved to both sides of each
trench in the coarse textured materials above the Bt
horizon. As an example, the Br distributions around
the four trenches along the right transect are
presented in Figure 5. Relatively high concentrations
of Br were observed mainly around the trench bottom
and sides on both transects. The highest Br
concentration, 58 mg kg-1, was for the sample
collected from a location around the first trench on
the left transect. For the right transect (Figure 5), the
top five highest Br concentrations were observed
around the first trench. Overall, little to no Br was
Figure 3. Photographs showing the dye-stained
areas around the 2nd lateral on the right
transect for the system installed in the Bt
horizon (A) and around lateral 3 on the right
transect for the system installed above the Bt
horizon at the Reedy Creek site (B). Note the
preferential movement of the tracer dye
through the macropores for system installed in
the Bt horizon and the stained areas in the
coarse textured materials and lack of stained
areas in the underlying clayey Bt horizon for
the system installed above the Bt horizon.
detected in a majority of the samples collected from
40 cm below the trenches. Lower Br concentration in
the soil around and below the trenches in this
experiment (where trenches were installed above
the Bt horizon) than the previous experiment (where
trenches were in the Bt horizon) indicates that most
of the solution applied to the trenches moved
laterally above the Bt horizon. The mass balance
analysis also showed that approximately 18% of the
Br applied to the trenches remained in the soil, with
recovery ranging between 11 and 26% for all
trenches.
59
Figure 4. Distribution of bromide (Br) concentrations (mg/kg) in soil samples collected from around the
four trenches along the right transect in the drainfield installed within the Bt horizon at the Reedy
Creek site.
Figure 5. Distribution of bromide (Br) concentrations (mg/kg) in soil samples collected from around the
four trenches along the right transect in the drainfield installed above the Bt horizon at the Reedy
Creek site.
60
Overall, the pattern of dye-stained areas and Br
concentration distributions around the trenches in
both experiments at this site indicates that most of
the solution infiltrated and moved through the Bt
horizon when the trenches were installed in the
clayey Bt horizon. On the other hand, little water
percolated through the Bt horizon when the trenches
were installed in the coarse-textured materials
above the Bt. In the later case, lateral movement of
water above the Bt horizon is the only plausible
explanation for hydraulic functioning of the
experimental system.
The assessment of the dye-stained areas
around the trenches along two transects (walls of the
pit) perpendicular to the trenches at the Clayton site
(data not shown) indicates that water infiltrated the
soil from the bottom and sidewalls of the trenches.
The stained areas around individual trenches,
however, were not symmetric or similar for all
trenches. In the fine-textured Bt horizon under the
coarse-textured A and E horizons, stained areas
were discontinuous and represented preferential
water flow through macropores.
Lack of uniformity of the dye-stained locations
was confirmed by the Br concentration around the
trenches. Although Br was detected in all the
samples that were collected from the sides and
bottom next to each of the four trenches along the
two transects, the concentrations were not uniform.
Detection of Br away from the trenches and the
isolated stained areas away from the trenches
indicate that preferential movement through
macropores is the way water and pollutants move
from trenches, particularly in the clayey horizons in
this type of soils.
For the last trench, Br concentrations of as high
as 37 mg kg-1 of soil were detected at more than 180
cm downslope from the trench. The Br recovery for
the four trenches varied considerably. Overall, less
than 50% of the total amount of Br that was applied
to the trenches was recovered. Based on the
recovery rate and the pattern of Br distribution
downslope of the system, it appears that lateral
movement and deep percolation are the main
mechanism for water movement through the soil at
this site.
For the Lake Wheeler site, the dye-stained
areas on the walls of the pit dug perpendicular to the
trenches were limited to a very close volume around
each trench. In general, the concentration of Br was
higher in the samples collected from below the
bottom of the trenches than the trench sides. As
expected, water movement through the bottom of
the trenches was not uniform but was mainly
through certain features of the materials. Although
we cannot prove it by our experimental data, we
believe water movement in the unsaturated zone
under the drainfield in the soil at this site is mainly
vertical with little lateral movement. We base the
conclusion on the fact that we did not observe any
restrictive layer to a depth of more than 150 cm
below the soil surface and that Br distribution was
limited to the drainfield area in the direction
perpendicular to the trenches. Almost all the Br
applied to the trenches was accounted for in the soil
samples that were collected from the site after
termination of tracer solution application.
CONCLUSIONS
This study has shown the following.
Water flow from septic system trenches is not
uniform.
• Water flow in the sandy-textured soils is through
interparticle pores.
• Water flow in clayey-textured soil is through
macropores (e.g., tubular root channels).
• In cases where trenches are installed in coarsetextured materials underlain by fine-textured Bt
horizon, lateral water flow above the Bt horizon may
be the primary mechanism for water movement
away from the drainfield.
• There is a great deal of soil variability with
respect to water flow.
• Soil variability and nature of water flow from the
trenches into and through the soil must be
considered when designing septic systems (or any
other waste dispersal system).
•
ACKNOWLEDGMENT
This study was supported by the N.C. Agricultural
Research Service and by a grant from the Water
Resources Research Institute of the University of
North Carolina.
REFERENCES
Amoozegar, A. 1992. Compact constant head
permeameter: a convenient device for
measuring hydraulic conductivity. p. 31–42. In G.C.
Topp, et al. (ed.) Advances in measurement of soil
physical properties: bringing theory into practice.
Spec. Publ. No. 30. SSSA, Madison, WI.
61
Amoozegar, A., and G.V. Wilson. 1999. Methods for
measuring hydraulic conductivity and drainable
porosity. p. 1149–1205. In R.W. Skaggs and J. van
Schilfgaarde (ed.) Agricultural drainage. ASA-SSSA
Monogr. SSSA, Madison, WI.
Cawthorn, J.W., V.S. Jenkins, R.B. Stephens, W.I.
Shope, R.C. Pleasants, D.G. Spangler, G.H.
Roberson, C.F. Eby, O.R. Demo, J.R. Woodruff,
J.H. Lane, J.P. Bryant, R.M. Craig, P.D. Sopher, and
D.W. Gross. 1970. Soil survey of Wake County,
North Carolina. USDA Soil Conservation Service,
Washington, DC.
Cogger, C., B.L. Carlile, D. Osborne, and E.
Holland. 1982. Design and installation of
low-pressure pipe waste treatment systems. UNC
Sea Grant College Publ. UNC-SG-82-03. North
Carolina State Univ., Raleigh.
Daniels, R., S.W. Buol, H.J. Kleiss, and C.A. Ditzler.
1999. Soil systems in North Carolina. Tech. Bull.
314. N.C. State Univ., Raleigh.
Gee, G.W., and J.W. Bauder. 1986. Particle-size
analysis. p. 383–411. In A. Klute (ed.) Methods of
soil analysis, part 1. Physical and mineralogical
methods. Agron. Monogr. 9. ASA and SSSA,
Madison, WI.
Greenberg, A.E., L.S. Clesceri, and A.D. Eaton.
1992. Standard methods for examination of water
and wastewater. 18th ed. American Public Health
Association, Washington, DC.
Kleiss, H.J., L.E. Aull, F.G. Averette, R.E. Horton,
and W.G. Woltz. 1981. Soils of the Central Crops
Research Station, Clayton, North Carolina, their
technical and useability classification. N.C. Agric.
Res. Serv., NCDA, and USDA, Raleigh.
Oron, G., J. DeMalach, Z. Hoffman, and R.
Cibotaru. 1991. Subsurface microirrigation with
effluent. J. Irrig. Drain. Div. Am. Soc. Civ. Eng.
117:25–36.
Vepraskas, M.J., Jongmans, A.G., Hoover, M.T., and
Bouma, J. 1991. Hydraulic conductivity of saprolite
as determined by channels and porous groundmass.
Soil Sci. Soc. Am. J. 55:932–938.
62
Potential Nitrogen Contribution from Septic Systems to
North Carolina’s River Basins
By Sushama Pradhan, Michael T. Hoover, Robert Austin, and Hugh A. Devine
Abstract
Little is known quantitatively about the extent of
nitrate-N (NO3 -–N) pollution from septic systems to
river basins. As a result, existing models and
nutrient management plans for North Carolina’s
river basins have typically ignored these potential
inputs (NCDENR, 1997). In an attempt to address
this, a Geographic Information System (GIS) based
on an area-driven normalization procedure was
developed and implemented to estimate potential N
loading from septic systems for each N.C. river
basin. This was accomplished by first aggregating
into watersheds the number of homes using septic
systems from 1990 census block information. This
number was then combined with the total population
of the river basin to produce a potential N loading
per year. A loading factor of 10 pounds per person
per year was assumed (Alhajjar et al., 1989;
Buetow, 2002).
Septic system usage ranged from 39% of the
population in the Catawba River basin to 82% in the
Hiwassee River basin. The septic system density
ranged from 14 septic systems per square mile in the
Chowan River basin to 53 septic systems per square
mile in the Catawba River basin. The Yadkin River
basin had the highest potential N loading (6,349,093
pounds per year), and the Savannah River basin had
the lowest (30,875 pounds per year).
Aggregations were also done on a sub-basin level
and 9 of the 17 watersheds had at least one sub-basin
with more than 40 septic systems per square mile.
The lowest potential N loading by sub-basin was
found in the Neuse14 sub-basin (7,366 pounds per
year), and the largest potential loading was found in
Yadkin4 sub-basin (1,206,880 pounds per year).
Results obtained from this study can be compared
with the potential N loading obtained from other
nonpoint sources such as agriculture, forestry, and
urban land use. For example, the potential N
contribution from septic systems in the Neuse River
basin exceeded 4 million pounds per year, which is
significant compared to urban lawn fertilization (3
million pounds per year) and substantially less than
that attributed to agriculture (84 million pounds per
year) (D.L. Osmond, personal communication, 2002).
Introduction
The N in household wastewater flowing into
septic tanks is primarily organic N. Mineralization
processes by microbes in the septic tank convert
organic N into ammonium-N (NH4–N). The N in
effluent leaving the septic tank is about 75–95%
NH4–N (NCDENR, 2003a). These compounds
become oxidized to NO3- as the sewage effluent
flows down through well-aerated soils.
Nitrate-N causes most of the primary adverse
impacts from septic systems according to Wilhelm
et al. (1994). Groundwater contamination with N
from septic systems is due to poor purification of the
effluent as a result of insufficient biochemical and
physical attenuation processes: e.g., denitrification
and ammonium adsorption (Andreoli et al., 1981).
Nitrate, a highly mobile anion, leaches through the
soil profile to the water table and into the
groundwater. In the absence of denitrification, the
nitrate can flow with the groundwater into adjacent
surface waters that serve as groundwater discharge
zones and can result in N contamination of surface
waters from septic systems (Buetow, 2002).
Sushama Pradhan, Graduate Student, NCSU Soil Science Dept., Raleigh, NC
Michael T. Hoover, Professor and Extension Specialist, NCSU Soil Science Dept., Raleigh, NC
Robert Austin, Extension/Research Associate, NCSU Soil Science Dept., Raleigh, NC
Hugh A. Devine; Professor; NCSU Parks, Recreation and Tourism Management Dept.; Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
63
Groundwater is an important national drinking
water resource. Ninety percent of rural households
and more than 75% of U.S. cities depend on
groundwater as a main source of drinking water
(Goodrich et al., 1991), whereas 52% of North
Carolinians rely on groundwater for their drinking
water supply. Levels of nitrate seldom exceed 0.1
-1
mg L as NO3 -–N under natural conditions. NO3 -–N
-1
levels in excess of 5 mg L usually are an indication
of human or animal waste or fertilizer runoff
(Chapman and Kimstach, 1992). High levels of NO3in drinking water are a potential health hazard; both
the World Health Organization and the U.S.
Environmental Protection Agency (1995) have set
their standards for NO3 -–N in drinking water supply
-1
at a maximum contaminant level of 10 mg L .
North Carolina has one of the highest rural,
nonfarm populations on a per-capita basis in the
country (Hoover et al., unpublished data, 1998).
People living in rural nonfarm residences depend
almost exclusively upon individual on-site septic
systems for treatment of household wastewaters.
On-site systems are the primary domestic
wastewater treatment system for approximately 50%
of the North Carolina’s population with an additional
40,000 to 50,000 new systems being installed
annually (Hoover, 1994).
Although on-site systems are extensively used
in the state, existing sub-basin nutrient models have
typically ignored the N inputs from septic systems to
North Carolina river basins. There are a number of
nutrient-sensitive rivers in state. Many have
regulated reduction of N originating from urban,
agriculture, and suburban land uses. However, due
to lack of knowledge regarding N loading from septic
systems, no reduction has been implemented for
this source within any river basin in the state. For
instance, the Neuse River basinwide nutrient
reduction plan (Neuse River Rapid Response Team,
1998) has no component to address nutrients from
septic systems. Therefore, the objective of this study
was to estimate potential N loading from septic
systems on both the river basin and sub-basin scales.
Materials and Methods
Census data were aggregated for each of North
Carolina’s 17 river basins as well as for 134 major
sub-basins. The 1990 census data included
information on method of wastewater disposal
whereas 2000 census data did not. Hence the 1990
data set was used for the analysis.
To estimate the potential N contribution from
septic systems on North Carolina River basins, an
area-driven normalization procedure was
implemented within GIS. The normalization
procedure was developed to provide a best estimate
for data with uncommon spatial boundaries. This
procedure was based on the assumptions that the
distribution of housing units using septic systems
and the corresponding population are spatially
uniform across the census block groups and that the
housing units using septic systems have only one
septic system per house. While these assumptions
are not always true, they provided a method suitable
for large-area analysis. Before the census block
group coverage and watershed–subwatershed
coverages were overlain, density values for
population and septic systems were calculated for
each census block group polygon. These normalized
values were used to re-aggregate the census data
by the major watershed–subwatershed boundaries.
A union operation within the GIS was used to
calculate common areas within the census block
groups and watersheds (Pradhan et al., 2002). This
combined coverage contained polygons for every
bisected block group and sub-basin across North
Carolina. In addition, each individual polygon
maintained as an attribute an identifier for both its
census block group membership and its sub-basin
membership. Through identifiers, it was possible to
sum both population and housing units using septic
systems by common identifiers (e.g., sub-basin id’s).
A value for total population and septic systems was
determined by multiplying these densities with the
area of each polygon. These numbers were then
summed by unique sub-basin identifier, and values
were calculated that represented the total population
and total number of septic systems per sub-basin.
Figure 1 illustrates the steps involved in this
procedure.
The population using septic systems for this
study was the total population in a subwatershed
multiplied by the proportion of housing units using
septic systems in that subwatershed. The total
amount of potential N that septic systems may be
discharging into the North Carolina’s River basins
was calculated by multiplying the number of people
that use septic systems with the average amount of
total N discharged (in septic tank effluent) per
person per year. The amount of N in septic tank
effluent was estimated to be 10 lbs per person per
year (Alhajjar et al., 1989; Buetow, 2002). It is
important to note that this analysis represented only
the potential N loading to each sub-basin, not the
actual loading. The estimates provided here did not
account for any N losses due to denitrification or
plant uptake prior to groundwater discharge into
rivers, streams, or other water bodies.
64
DATA SETS USED
The GIS census block boundary layer for NC was
obtained from the Topologically Integrated
Geographic Encoding and Referencing (TIGER) line
files that were developed by U.S. Department of
Commerce, Bureau of the Census data. TIGER-line
files are based predominantly on the U.S.
Geological Survey 1:100,000 scale digital line graph
files with state plane coordinate system and NAD83
datum.
The watershed boundary layer was obtained
from the N.C. Center for Geographic and
Information Analysis (NCCGIA). The watershed
boundary layer, 1: 24,000 scale, has a state plane
coordinate system and NAD83 datum.
Results and Discussions
There are 17 river basins, 134 major sub-basins
and 5,696 census block groups within NC. Sizes of
river basins vary substantially (e.g., 171–9,202
square miles). Similarly, size ranges significantly at
the sub-basin level. The smallest sub-basin was
WOK5 (15 square miles) of the White Oak River
basin, and the largest sub-basin was LTN2 (1,023
square miles) of the Little Tennessee River basin
(see Table 1).
The number of housing units using septic
systems ranged from 3,198 housing units
(Savannah River basin) to 263,299 housing units
(Yadkin River basin). Sub-basin SAV1 of the
Savannah River basin has the lowest (79) number
of the housing unit using septic system whereas
sub-basin YAD4 of the Yadkin River basin had the
highest (52,742) number of housing units using
septic systems. Density distribution of septic
systems and potential N loading for each of the 17
river basins in NC is discussed in following
paragraphs.
10 acres
5 septic systems
10 acres
15 septic systems
Census block
group
coverage
Normalization of census data
by land area
0.5 septic systems / ac.
1.5 septic systems / ac.
Census block group coverage with
normalized value of density of septic
systems and density of population
River basin coverage
Union operation
>
>
>
>
>
Total systems = 2.0 acres* 1.5 sys/ac
Total systems = 5.0 acres* 0.5 sys/ac
>
Total systems = 5.0 acres* 1.5 sys/ac
Total systems = 2.0 acres* 0.5 sys/ac
>
Total systems = 1.5 acres* 1.5 sys/ac
>
Total systems = 1.5 acres* 0.5 sys/ac
Figure 2. Flow chart showing the steps involved in union procedure.
Total systems = 1.5 acres* 0.5 sys/ac
Total systems = 1.5 acres* 1.5 sys/ac
65
STATEWIDE USE OF SEPTIC SYSTEMS
Septic systems as well as public or community
sewer systems were the primary means of
household wastewater treatment systems in NC.
According to the 1990 census, 48% of the total
housing units and population in N.C.’s watersheds
used septic systems. Other systems such as privies,
outhouses and straight pipes discharging directly to
streams were used by approximately 2% of the
population (Figure 2). Hence, 50% of the state’s
population and housing in the state depend on onsite wastewater technologies.
Septic system usage for N.C.’s 17 watersheds
ranged from 82% to 39% of the population,
Table 1. Septic system usage, density, and potential nitrogen contributions in N.C.’s river basins.
River basin
Basin
(mi2)
Septic density
(per mi2)
N-loading
(lbs/yr)
Broad
1,508
72,940
49,622
114,254
33
1,142,540
Cape Fear
9,202
612,703
245,162
588,930
27
5,889,304
Catawba
3,198
436,538
168,636
406,797
53
4,067,971
Chowan
1,301
25,710
16,141
39,121
14
391,208
French Broad
2,820
169,052
95,163
201,250
34
2,012,498
626
14,145
11,606
21,867
19
218,667
Little Tennessee 1,770
38,577
31,009
53,666
18
536,664
Hiwassee
Total housing
units
Total
septic
Population
using septic
Lumber
3,312
117,002
76,612
164,882
23
1,648,819
Neuse
5,621
417,132
161,500
396,589
29
3,965,894
752
25,874
17,729
36,905
24
369,049
Pasquotank
2,156
54,558
39,642
67,311
18
673,107
Roanoke
3,421
110,853
67,078
158,928
20
1,589,278
171
4,159
3,198
3,088
19
30,875
4,518
147,570
72,052
175,887
16
1,758,866
205
10,248
7,018
10,945
34
109,453
White Oak
1,045
77,858
40,069
91,337
38
913,369
Yadkin
7,159
483,142
263,299
634,909
37
6,349,093
48,786
2,818,063
1,365,536
3,166,665
28
31,666,655
New
Savannah
Tar Pamlico
Watauga
sum/wt. avg
66
depending upon the specific river basin. More than
50% of the population used septic systems in 12 of
the 17 river basins in NC. The Hiwassee, Little
Tennessee, and Savannah river basins had the
greatest use of septic systems on a percentage
basis with nearly 80% of the population using septic
systems. These river basins are located in the
mountainous and rural areas of the state. However,
these same river basins also had the lowest overall
population densities in the state. Therefore, the total
number of septic systems was relatively low in each
of these watersheds. On the other hand, more than
55% of the housing units used public sewers in the
Cape Fear, Catawba, and Neuse river basins. These
river basins are located at the central part of the
state and had relatively high densities of
development.
There were 1,365,536 septic systems serving
over 3 million people in NC as of the 1990 census.
Obviously, as of 2002, we would expect that number
to be substantially larger. The number of new
system operation permits or certificates of
completion typically ranged between 36,715 and
54,575 new systems (excluding repair permits for
existing systems) installed each year during the
1990s and early 2000s (NCDENR, 2003b). These
new systems were not reflected in the 2000 census
data since method-of-wastewater-treatment data
were not collected during that census.
As an example, if an average of 45,000 septic
systems were installed each year and 10,000
existing septic systems per year were connected to
public sewers (the actual number connected to
sewer is unknown), then there would be
approximately 1,800,000 septic systems in use by
the end of 2002. If, as estimated from the 1990
census data, each system serves an average of 2.3
people, then 41,400,000 pounds N were potentially
generated statewide by 2002.
SEPTIC SYSTEM DENSITY
The distribution of septic systems on both a
river basin scale (Figure 3) and a sub-basin scale
(Figure 4) illustrates substantial variability
throughout the state. The Catawba River basin had
the highest septic system density with 53 septic
systems per square mile. This can be explained by
development along major highways, like I-85 and
I-77, that pass through this basin. In addition, there
are substantial water bodies that serve as
recreational resources that encourage development.
There are several cities and their associated
urban fringe areas located along highways including
the city of Charlotte in the Catawba River basin.
Figure 2. Distribution of housing units using septic systems, sewer systems and other means for North
Carolina’s river basins.
67
Figure 3. Density distribution of septic systems river basin scale in North Carolina.
Figure 4. Density distribution of septic systems in sub-basin scale in North Carolina.
68
Additionally, major water bodies such as Lake
Norman occur in this watershed. The population
density of this river basin (326 people per square
mile) was by far the highest among all the river
basins of NC.
Both the Catawba and White Oak river basins
were in the top three watersheds in the state
regarding septic system density, population density,
and potential N-loading rate (pounds per square
mile) from septic systems. Hence, the septic system
nutrient loadings may be more substantial in these
watersheds than in other watersheds. The Yadkin
River basin also had a relatively high septic system
density and potential N-loading rate as well as the
largest total potential N loading of any watershed.
In contrast, the Chowan River basin had the
lowest septic system density and was mostly rural,
with few major highways and limited numbers of
cities, waterfronts, or recreational areas that were
not served by public sewers. Most of the land, about
89%, was in forest or agriculture. The population
density was only 48 people per square mile in
comparison to state average of 136 people per
square mile in 1990.
The actual impacts of septic systems on
groundwater and surface water will depend upon
more than the potential loading. Soil conditions,
groundwater aquifer characteristics, geochemistry,
and other conditions will influence the fate and
transport of a contaminant such as N. However, the
U.S. Environmental Protection Agency (USEPA,
1977) suggested that septic system density was
related to groundwater contamination problems
when observed on a regional scale. It categorized
density into three groups based on the number of
septic systems per square mile: low (<10), medium
(10–40), and high (>40).
In 1990, only the Catawba River basin had a
septic system density in excess of the 40 systems
per square miles, which according to USEPA (1977)
might indicate a high likelihood of regional
groundwater contamination problems. In the same
year, the White Oak, Yadkin, Watauga, Broad, and
French Broad watersheds had 30–40 septic systems
per square mile and may soon, if not already,
exceed 40 systems per square mile. EPA’s 40septic-systems-per-square-mile value is not
necessarily an indicator that regional contamination
is imminent since factors such as soils, geology,
groundwater dynamics, and denitrification potential
must be considered. However, these six river basins
were the most susceptible of N.C.’s 17 river basins
to pollution problems from septic systems when
considered strictly on a density basis. Further
assessment of soils, geology, and other factors
should be considered for these watersheds so as to
determine the actual loadings as well as the true
impacts of septic-system-derived N.
Individual sub-basins within five of these six
watersheds had high septic system densities. There
were also individual sub-basins in the Cape Fear,
Neuse, and Pasquotank river basins with high
densities. As is often the case, these high-density
sub-basins typically adjoin shellfish-harvesting
waters, water-supply watershed reservoirs, beaches,
swimming waters, or important groundwater
aquifers.
Extensive variation in density occurred on a
sub-basin level within individual watersheds. The
sub-basins with the highest and the lowest septicsystem densities were both located within the
Pasquotank River basin. Pasquotank sub-basin
PAS56 had the highest in the state with 299 septic
systems per square mile, whereas Pasquotank subbasin PAS51 had only five septic systems per
square mile. Sub-basin PAS56 contains major
recreational areas like Kitty Hawk and Wright
Brothers Memorial and cities like Nags Head and
Kill Devil Hills. On the other hand, sub-basin PAS51
is mostly public land with very little urban area or
development. The population density of sub-basin
PAS56 was more than 23 times that of sub-basin
PAS51.
Sub-basin WOK3 of the White Oak had the 2nd
highest septic system density (97 septic systems per
square mile). This sub-basin was spread across the
Atlantic Ocean coastline and included numerous
beach cities like Atlantic Beach, Beaufort, Morehead
City, and Newport. It had an overall population
density of 187 people per square mile. The next
highest septic-system densities were in sub-basins
CTB37 and CTB36 of the Catawba, with 96 and 93
septic systems per square mile, respectively. Subbasin CTB37 contains portions of Bessemer City
and South Gastonia and had a population density of
620 people per square mile. Sub-basin CTB36
contains part of Gastonia and Bessemer City and
had a population density of 618 people per square
mile. These cities are located along highway I-85.
Septic-system density was higher in basins and
sub-basins with more urbanized areas than in those
with less urbanized area. Sub-basin CTB34 of the
Catawba contains the city of Charlotte and had a
population density of 1385 people per square mile,
many of whom were served by public sewers but
still had a septic system density of 60 systems per
square mile. Similarly sub-basin NEU2 of the Neuse
contains the cities of Raleigh, Durham, and Cary
with a population density of 571 people per square
mile but still had a septic system density of 48
systems per square mile. Even though most of the
population in these cities had access to public
69
sewers, substantial densities of septic systems
occurred in their urban fringes. In general, basins
and sub-basins that included major highways,
waterfronts, and/or recreational areas had higher
septic densities. In such areas, cities were spread
out along the highways or waterfronts; and public
sewer systems had not been developed to cover the
intervening areas.
POTENTIAL NITROGEN CONTRIBUTIONS FROM
SEPTIC SYSTEMS STATEWIDE
Total potential N loading from septic systems in
NC was approximately 32 million pounds per year
based upon 1990 census data. As indicated earlier,
this may have increased to over 41 million pounds
per year by 2002. The total potential N loading from
septic system on a statewide basis seems
numerically large (32 million pounds per year based
upon 1990 data). However, when compared to other
potential N sources—such as agriculture, lawn
fertilization, atmospheric deposition, and
stormwater, this number seems relatively small on a
statewide basis. Even so, there may be individual
basins or sub-basins in which septic-system
potential N contributions may be large relative to
these other sources. Therefore, it may be useful to
use septic system density and/or potential N loading
on a basinwide or sub-basin scale as a screening
tool to identify where further more-detailed
assessment of loading is targeted.
The highest potential N contributors based upon
the 1990 census data were the Cape Fear, Catawba,
Neuse, and Yadkin river basins in the central and
eastern parts of the state (Figure 5). Septic systems
in just two of the basins—the Yadkin and Cape
Fear—may have contributed over 40% (>12 million
pounds per year) of the septic-system-derived N in
the state. The lowest contribution was from the
Savannah River basin with potential N loading of
only 30,875 pounds per year.
Nitrogen loading on a river basin scale was the
result of the size of the river basin, the septic
system density, or the population using septic
systems in that river basin. The Yadkin River basin
is the second largest in NC but has higher potential
N loading than the Cape Fear, which is the largest
river basin in NC. This is the case because the
Yadkin has a higher septic system density and
population using septic systems than the Cape Fear.
Septic systems in each of these basins potentially
contribute nearly 6 million pounds per year of N to
these watersheds based upon 1990 census
population data. Septic systems in the Catawba and
Neuse river basins each potentially contribute nearly
4 million pounds per year of N to these watersheds.
The potential N-loading rates (pounds N per square
Figure 5. Cumulative potential nitrogen loading in North Carolina’s River basins.
70
mile per year) on a river-basin basis are greatest in
the Catawba, Yadkin, and White Oak river basins,
respectively.
Figure 6 illustrates potential N contribution from
septic systems on a sub-basin basis for the 134 subbasins in North Carolina. The highest potential N
loading at a sub-basin level was from Yadkin subbasin YAD4, at over 1 million pounds of N per year.
Also, river basins that did not have the largest
potential N loading on a complete watershed basis
could still have sub-basins with substantial N
contributions. For instance, the French Broad River
basin potentially contributes 2,012,498 pounds N per
year, but at the sub-basin level, sub-basin FRB2
potentially contributes nearly half of that or
1,087,065 pounds N per year. This is the second
highest potential N loading in the state at the subbasin level.
The Cape Fear, Catawba, French Broad, Neuse,
White Oak, and Yadkin river basins each had at
least one sub-basin that potentially contributed more
than 450,000 pounds N per year. These sub-basins
are primarily located in developing areas, along
major highway corridors, in beach communities, and
in areas surrounding surface waters such as large
lakes, sounds, rivers, and beaches. For example,
sub-basin YAD4 contains Winston-Salem and other
small cities located along highway I-40. Sub-basin
FRB2 contains Asheville and Hendersonville as well
as highways I-40 and I-26.
Many of the beach communities along N.C.’s
Barrier Islands had very high densities of septic
systems (Figure 4) and high potential N-loading
rates on a pounds-of-N-per-square-mile basis but
did not have high total potential N loadings (Figure
6). The aerial extent of these sub-basins was
generally so small that the cumulative potential N
loading was not as great as within larger sub-basins
despite the high densities of septic systems.
Conclusions
1. Potential N loading was mainly influenced by
density of population using septic systems (or
density of septic systems) and the size of the
watershed.
2. Sub-basins with potential high N contributions
were primarily located in developing areas, along
major highway corridors, in beach communities, and
in areas surrounding surface waters—such as lakes,
sounds, rivers, and beaches.
3. Statewide, the overall potential N contribution
due to septic systems did not seem substantial when
compared to other potential N sources.
4. Density distribution of septic systems and
potential N-loading results from this study can be
Figure 6. Cumulative potential nitrogen loading for North Carolina’s sub-basins.
71
used as a screening tool to identify the most critical
areas for further study of N pollution from septic
systems in river basin and sub-basin levels.
5. Sub-basins with high septic system densities
and/or large potential N loadings are areas where
further investigation is recommended to assess the
actual N loadings due to septic systems.
6. Results from this study can be compared with
potential N loading obtained from other nonpoint
sources such as agriculture, forestry, and urban land
use: e.g., the potential N contribution from septic
systems in the Neuse River basin exceeded 4
million pounds per year, which is significant
compared to urban lawn fertilization (3 million
pounds per year) yet substantially less than that
attributed to agriculture (84 million pounds per year).
References
Alhajjar, B.J., J.M. Harkin, and G. Chesters. 1989.
Detergent formula and characteristics of wastewater
in septic tanks. J. Water Pollut. Control Fed.
61:605–613.
Andreoli, A., R. Reynolds, N. Bartilucci, and R.
Forgione. 1981. Nitrogen removal in a subsurface
disposal system. Water Sci. Technol. 13:967–976.
Buetow, W.S. 2002. On-site wastewater nitrogen
contributions to a shallow aquifer and adjacent
stream. M.S. thesis. North Carolina State University,
Raleigh. 155 p.
Chapman, D., and V. Kimstach. 1992. The selection
of water quality variables. p. 51–119. In D. Chapman
(ed.) Water quality assessments. Chapman and
Hall, London.
Goodrich, J.A., B.W. Lykins, Jr., and R.M. Clark.
1991. Drinking water from agriculturally
contaminated groundwater. J. Environ. Qual.
20:707–717.
Hoover, M.T. 1994. Septic tank systems. Soil
Science Facts. Dept. of Soil Science, NCSU Agric.
Ext. Serv., Raleigh, NC.
Neuse River Rapid Response Team. 1998. Nitrogen
reduction plan for Neuse River approved, along
with immediate buffer protection [Online]. Available
at http://www.enr.state.nc.us/neuse/newsrels/
reduce.htm (posted 24 Jun. 1997; verified 29 Oct.
2003).
N.C. Department of Environment and Natural
Resources (NCDENR). 1997. Report of proceedings
on the proposed Neuse River Basin nutrient
sensitive waters (NSW) management strategy;
Environmental Management Commission meeting,
June 12, 1997. NCDENR Division of Water Quality,
Raleigh, NC.
N.C. Department of Environment and Natural
Resources (NCDENR). 2003a. NPS pollution from
nitrogen [Online]. Available at http://
www.deh.enr.state.nc.us/oww/nonpointsource/
NPSseptic/npsnitrog.htm (verified 4 Dec. 2003).
N.C. Department of Environment and Natural
Resources (NCDENR). 2003b. On-site activity
reports [Online]. Available at http://
www.deh.enr.state.nc.us/oww/
Program_improvement_team/Pit_Index.htm
(verified 4 Dec. 2003).
Pradhan, S., M.T. Hoover, and R. Austin. 2002.
Enhanced GIS procedures for assessment of
potential nitrogen loading from on-site septic
systems to the Neuse River basin [abstract]. Soil
Sci. Soc. N.C., Proc. 45: 57.
U.S. Environmental Protection Agency (USEPA).
1977. The report to Congress — waste disposal
practices and their effects on groundwater. USEPA
Office of Water Supply, Washington, DC.
U.S. Environmental Protection Agency (USEPA).
1995. Drinking water regulations and health
advisories. USEPA Office of Water Supply,
Washington, DC.
Wilhelm, S.R., S.L. Schiff, and J.A. Cherry. 1994.
Biogeochemical evolution of domestic wastewater in
septic systems. 1. A conceptual model. Ground
Water 32:905–916.
72
Analysis of Tire Chips as a Substitute for Stone Aggregate
in Nitrification Trenches of On-site Septic Systems:
Status and Notes on the Comparative Macrobiology
of Tire Chip vs. Stone Aggregate Trenches
By Barbara Hartley Grimes, Steve Steinbeck, and Aziz Amoozegar
Introduction
It is estimated that 242 million tires (about one
tire per person) are discarded annually in the United
States (USEPA, 1999). This high number of used
tires presents a significant problem for disposal and
has led to intense research and development for
reusing and recycling tires. In 1999–2000, counties
in NC reported receiving 9.5 million tires (136,536
tons in monolandfills) (NCDENR, 2001). Because of
the high volume of waste tires, problems associated
with their disposal, and aesthetic problems,
expansion and innovation of reuse of used tire
products is being addressed aggressively. Chipped
or shredded tires, are being used for a wide variety
of products, including playground covers, doormats,
roadbed, fill, shoes, and aggregate substitute in
septic system drainfields. This paper will describe
and analyze the current available information on the
use of tire chips as a substitute for stone aggregate
in septic system drainfields.
In more than 17 states, tire chips/shreds are
currently permitted for use or are under
experimental evaluation as a substitute for stone
aggregate in septic system drainfields. Some of the
scrap tires in NC are being chipped and exported to
South Carolina for use in septic systems. Tire chips
have recently been approved as an aggregate for
septic systems in NC (NCDENR, 2003).
The number of discarded tires used in on-site
systems can be significant. For example,
approximately 2.3 million passenger tire equivalents
in Georgia, 300 tons of tire chips in Iowa, 100
million tires in Florida, and about 30% of used tires
in Oklahoma are being used in septic systems.
Specifications and Definitions :
General Description
Tires can be cut into small pieces called tire
chips or tire shreds by various techniques. The State
of New York (2000) roundtable defines chips as “a
classified scrap tire . . . which is generally two
inches (50.8 mm) or smaller and has most of the
wire removed . . .” and shreds as “pieces of scrap
tires that . . . are generally between 50 mm (1.97
inches) and 305 mm (12.02 inches) in size.”
Physical characteristics of tire chips—such as size,
wire protrusion, and fines—are controllable factors
in the processing of tire chips. Based on this, the
term tire chips is more suitable as a substitute for
stone aggregate than the term tire shreds.
According to the Texas Natural Resource
Council Commission (TNRCC), although passenger
tires may vary in size and shape, they have similar
general physical and chemical characteristics and
are composed approximately of 85% carbon, 10–
15% ferric material, and 0.9–1.25% sulfur (TNRCC,
1999b). More specific information on rubber, metals,
and other compounds in tires can be obtained from
the Texas Natural Resource Conservation
Commission (TNRCC, 1999a). For example, studies
have shown that new versus used tire chips have
similar performance when used as aggregate in
septic systems (Spagnoli et al., 2001).
The relatively stable structure of tire chips
makes them a suitable substitute for stone
aggregate in the septic system. In addition, tire
chips are three times lighter than stone aggregate
(e.g., a cubic yard of stone aggregate is 2,800
pounds and a cubic yard of tire shreds is 800
Barbara Hartley Grimes, NonPoint Source Pollution Program Coordinator, NCDENR, Raleigh, NC
Steve Steinbeck, NonPoint Source Pollution Program Team Leader, NCDENR, Raleigh, NC
Aziz Amoozegar, Professor, NCSU Soil Science Dept., Raleigh, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
73
pounds). Also, in many cases, tire chips have shown
to be 1/3 the cost of stone aggregate for use in
septic systems (Spagnoli et al., 2001).
Regulations in states where tire chips are
approved as a substitute for stone aggregate in onsite systems require them to be of similar size as
stone aggregate (approximately 2 inches), with wire
protrusion of ½ inch or less. These regulations also
require a “no fines limit” and geotextile fabric to
cover the tire chips before ground covering. The
major differences in state regulations are in the
percent of tire chips meeting specification required
(80%, 90%, etc.) and the oversight, inspection, and/
or certification of the tire chip specifications. Few
states address the bead wires, cleanup, and any
limits on depth to groundwater—other than standard
installations.
Main Issues in Tire Chip
Substitution —
Demonstration / Experimental
Projects
Concerns for tire chip use include storage,
handling of chips with protruding wires, postinstallation cleanup of stray tire chips, potential for
compression or compaction, and durability of the
chips. In storage, the accumulation of dirt and stray
materials need to be prevented. Persons handling
the chips should use care, wear thick gloves and
appropriate clothing (including thick-soled shoes),
and have current tetanus protection. The cleanup
must be addressed in the post installation
inspection.
Research has shown that compaction is not a
significant problem, and our inspection of tire chips
in the trenches of a number of 8-year-old drainfields
in SC revealed that the tire chips were not degraded
or damaged by wear. These demonstrate the
durability of tire chips in septic systems.
Recommendations have been made from several
research/demonstrations projects that tire chips
should be firmly compacted prior to covering with
geotextile fabric.
One field survey conducted in SC did not show
a significant number of failures in tire chip systems
that were greater than 10 years old or evidence of
settling problems over the drainfields. Porosity was
found to be higher with tire chips than stone (60%
for tire chips; 40% for stone) (Robinson, 2000;
Sengupta and Miller, 1999, 2000; Spagnoli et al.,
2001).
Sewage Distribution, Performance,
and Biomat Formation
Performance studies comparing stone
aggregate drainlines and tire chip aggregate
drainlines in various combinations of alternating
drainfields and alternating drainlines, show in all
cases equivalent or similar wastewater dispersal to
the soils within the trenches filled with stone
aggregate and tire chips drainfields (Amoozegar and
Robarge, 1999; Robinson, 2000; Sengupta and
Miller, 1999, 2000; Spagnoli et al., 2001).
Permeability of tire chips was found to be equal to
that of stone aggregate. In some cases, less
ponding was recorded in the tire chip systems than
systems that were constructed using stone
aggregate (Robinson, 2000; Sengupta and Miller,
1999, 2000; Spagnoli et al., 2001).
Waste treatment efficiency in all studies using
tire chips was equivalent to that achieved in stoneaggregate drainfields. Wastewater treatment testing
in more than one project examined BOD5, COD,
TSS, ammonia-nitrogen, nitrate, fecal coliforms, and
pH, and showed equivalent treatment, except the
wastewater treatment efficiency in tire-chip
trenches, sometime took several months to reach
the same rates. Conductivity profiles demonstrated
little precipitation in either type of aggregate
(Robinson, 2000; Sengupta and Miller, 1999, 2000;
Spagnoli et al., 2001).
Biomat formation and macrobiology of tire chips
in comparison to stone aggregate systems
examined in NC and SC (Appendix I) demonstrated
a thicker biomat and a surprising level of supported
invertebrates in the tire chip trenches (Appendix I).
Only nematodes were found in a two-year-old
system in NC, demonstrating an aerated system that
allows them to provide an additional treatment of
waste constituents. In the S.C. systems (> 8 years),
we found more trophic levels (feeding types) of
micro- and macro-organisms, which indicate a
stable ecological wastewater treatment community
(Ali et al., 1991; Feachem et al., 1977; Scott, 1961;
Steinhaus and Brinley, 1957; Usinger and Kellen,
1955). The organisms included grazers, saprophytic
feeders, and filter feeders.
The complexity and diversity of organisms
demonstrates the potential for additional levels of
wastewater treatment in tire-chip aggregate, keeps
the biomat pores open, promotes healthy biomat
regrowth by grazing, and indicates a healthy and
diverse ecosystem in the tire chip trenches (Ali et
al., 1991; Feachem et al., 1977; Scott, 1961;
74
Steinhaus and Brinley, 1957; Usinger and Kellen,
1955). In comparison, only a few protozoa were
found in a stone-aggregate system in SC.
Evaluation of both stone-aggregate and tire-chip
systems that were overloaded (i.e., high level of
ponding) showed that that the healthy ecosystem
was not present in tire-chip trenches when
overloaded.
A Question of Leachates
Major in-depth studies of leachate from tire-chip
versus stone-aggregate drainfields include
Amoozegar and Robarge (1999) in NC; Burnell and
McOmber (1997); Envirologic, Inc. (1990); Liu et al.
(1998); Robinson (2000); Sengupta and Miller
(1999, 2000); and Spagnoli et al. (2001). One of the
major questions raised in using tire chips as a
substitution for stone aggregate is the potential
leaching of various constituents from the tire chips.
Bench studies and field testing have examined tire
chip leachate under normal and worst-case-scenario
conditions (Amoozegar and Robarge, 1999; Burnell
and McOmber, 1997; Envirologic, Inc., 1990; Liu et
al. (1998); Robinson (2000); Sengupta and Miller
(1999, 2000); Spagnoli et al., 2001). The pollutants
of interest in these studies indicate that volatile and
semi-volatile compounds do not enter the leachate.
Other studies have demonstrated that ground rubber
and tire chips actually remove some of the organic
compounds from fluids percolating through them
(Gunasekara et al., 2000; Spagnoli et al., 2001).
Studies under typical septic system conditions
have shown that tire-chip leachate contains high
concentrations of iron. The levels of iron, which is a
secondary drinking water contaminant (aesthetic),
however, does not seem to pose a health problem.
The studies at the Chelsea Center showed that tire
chips were actually a sink for iron when compared to
the influent concentration (Sengupta and Miller,
1999, 2000). In many studies, manganese
(secondary drinking water standards) was also
higher in the tire chip leachate than in the aggregate
leachate (Spagnoli et al., 2001). In the Chelsea
studies, on the other hand, manganese
concentration was higher in the effluent in the D-box
but was of equivalent concentrations in stone
aggregate and tire chips in the trenches (Sengupta
and Miller, 1999, 2000). In the Chelsea studies, zinc
was lower than secondary drinking water standards;
in both trenches zinc concentrations were lower than
in the distribution box while paralleling D-box
fluctuations (Sengupta and Miller, 2000).
As for the effluent macrobiology in the trenches,
it appears that the iron in the presence of some
unknown factor(s) in tire chips enhances
macrobiological growth. Accumulation of harmful
trace metals does not appear to occur as evident by
the biological growth in the S.C. systems (Appendix I).
Overall, it appears that tire chip substitution for
stone aggregate is an excellent alternative for stone
aggregate for on-site systems in regard to
wastewater treatment, durability, and economics.
Using tire chips aggregate in septic systems also
provides a viable solution to recycling used tire
wastes. From the data, it is recommended a 1:1
substitution can be used in NC. Due to biological
studies and other researchers’ recommendations
(Spagnoli et al., 2001), we do not recommend that
tire chips be used in areas with seasonal high water
tables, using less than one foot separation for Group
1 (sand, loamy sand) (1.5 feet in sandy soils) or
conditions (e.g., undersizing) that result in
overloading the drainfields. Additionally, physical
hazards, worker safety, and compliance with the
specifications must be addressed.
References
Ali, A., Moh Leng Kok-Yokomi, and J.B. Alexander.
1991. Vertical distribution of Psychoda alternata
(Diptera:Psychodidae) in soil receiving wastewater
utilized for turf cultivation. J. Mosquito Control
Assoc. 12(2):287–289.
Amoozegar, A., and W.P. Robarge. 1999. Evaluation
of tire chips as a substitute for gravel in the trenches
of septic systems [final report submitted to the
Division of Pollution Prevention and Environmental
Assistance, N.C. Department of Environment and
Natural Resources, and Chatham County Board of
Commissioners]. N.C State Univ., Raleigh. 133 p.
[Available online http://www.p2pays.org/ref/03/
02627.pdf].
Burnell, B.N., and G. McOmber. 1997. Used tires as
a substitute for drainfield aggregate. In M.S.
Bedinger, et al. (ed.) Site characterization and
design of on-site septic systems. Am. Soc. Test.
Mater. (ASTM) Spec. Tech. Publ. 1324. ASTM,
Philadelphia, PA.
Daniels, J., and B. Bird. 1993 . A report on the use
of scrap tire shreds as soil absorption media.
Prepared for the Kansas Department of Health and
Environment Local Protection Plan Grant. 8 p.
Feachem, R.G.A., M.G. McGarry, and D.D. Mara
(ed.). 1977. Water wastes and health in hot
climates. John Wiley, New York.
75
Envirologic, Inc. 1990. A report on the use of
shredded scrap tires in on-site sewage disposal
systems. Envirologic, Inc., Brattleboro, VE. 9 p.
12 p. (Available online with updates at http://
www.chelseacenter.org/pdfs/TechReport12.PDF.)
(Verified 20 Nov 2003.)
Gunasekara, A.S., J.A. Donovan, and B. Xing. 2000.
Ground discarded tires remove naphthalene,
toluene, and mercury from water. Chemosphere
41(8):1155–1160.
Sengupta, S., and H. Miller. 2000. Investigation of
tire shreds for use in residential subsurface leaching
field systems: a field scale study. Tech. Rep. 32.
Chelsea Center for Recycling and Economic
Development, Univ. of Mass., Lowell. 33 p.
(Available online with updates at http://
www.chelseacenter.org/pdfs/TechReport32.pdf.)
(Verified 20 Nov 2003.)
Liu, H.S., J.L. Mead, and R.G. Stacer. 1998.
Environmental impacts of recycled rubber in light fill
applications: summary and evaluation of existing
literature. Tech. Rep. 2. Plastics Conversion Project,
Chelsea Center for Recycling and Economic
Development, Univ. of Mass., Lowell. 18 p.
(Available online with updates at http://
www.chelseacenter.org/pdfs/TechReport2.pdf.)
(Verified 20 Nov 2003.)
N.C. Department of Environment and Natural
Resources (NCDENR), Division of Waste
Management. 1998. N.C. solid waste management
annual report (1996–June 1997). NCDENR, Raleigh.
25 p.
N.C. Department of Environment and Natural
Resources (NCDENR), Division of Waste
Management. 2001. N.C. solid waste management
annual report (1999–June 2000). NCDENR, Raleigh.
25 p.
N.C. Department of Environment and Natural
Resources (NCDENR). 2003. NCDENR Division of
Environmental Health, On-site Wastewater Section
web site [Online]. Available at http://
www.deh.enr.state.nc.us/oww/ (verified 20 Nov
2003).
Robinson, S.J. 2000. The use of chipped tires as
alternate aggregate in septic system leach fields.
M.S. thesis. State Univ. of New York, Syracuse.
234p.
Scott, H.G. 1961. Filter fly control at sewage plants.
The Sanitarian 24(1):14–17.
Sengupta, S., and H. Miller. 1999. Preliminary
investigation of tire shred for use in residential
subsurface leaching field systems: a field scale
study. Tech. Rep. 12. Chelsea Center for Recycling
and Economic Development, Univ. of Mass., Lowell.
Spagnoli, J., A.S. Weber, and L.P. Zicari. 2001. The
use of tire chips in septic system leachfields. Center
for Integrated Waste Management, Univ. of Buffalo,
Buffalo. 92 p.
State of New York. 2000. NYS roundtable consensus
on tire management parameters for legislative
development [Online]. Available at http://
www.rma.org/scrap_tires/state_issues/
nys_roundtable.pdf. (Verified 20 Nov 2003.)
Steinhaus, E.H., and F.J. Brinley. 1957. Some
relationships between bacteria and certain sewageinhabiting insects. Mosquito News 17:299–302.
Texas Natural Resource Conservation Commission
(TNRCC). 1999a. TNRCC information: the
composition of a tire. TNRCC, Austin, TX.
Texas Natural Resource Conservation Commission
(TNRCC). 1999b. TNRCC information: using tire
shreds in on-site sewage facilities (septic systems).
TNRCC, Austin, TX.
U.S. Environmental Protection Agency (USEPA).
1999. A quick reference guide. USEPA Rep. 530-B99-002. U.S. Gov. Print. Office, Washington, DC.
Usinger, R.L., and W.R. Kellen. 1955. The role of
insects in sewage disposal beds. Hilgardia
23(10):263–321.
Selected Additional References and Web Resources
http://www.rose-hulman.edu/~sutterer/
WASTErefs.html. REFERENCES ON USE OF
WASTE OR OTHER UNCONVENTIONAL
MATERIALS IN EARTHWORK
76
APPENDIX I. MACROBIOLOGY
(Barbara Hartley Grimes, Ph.D., OSWS NPS
Coordinator: DEH : NCDENR)
MACROBIOLOGY METHODOLOGY: 2–8 years
post-installation: hand digging in trenches; Evian
water to wash out organisms from biomat.
Dissecting microscope used to examine the biomat
and tire chips. Identification to taxonomic class.
RESULTS:
A. N.C. Experimental Wastewater System:
N.C. rules of conventional installation. (Approval
online OSWS) Dr. Aziz Amoozegar Soil Science
NCSU System with alternating stone aggregate
trenches and tire chip trenches. Results of sampling
the biomat for protozoa and metazoa (higher forms)
EXCAVATION:
Tire chips: well-structured “honeycomb”; does not
collapse on excavation
Stone aggregate: no structure; collapses on
excavation
APPEARANCE OF AGGREGATE:
of systems and soils — systems were at least eight
years old. Results of sampling the biomats for
protozoa and metazoa (higher forms) (as always —
other factors involved — heavy rains days before
our trip)
EXCAVATION:
Tire chips: well-structured “honeycomb”; does not
collapse on excavation; After eight years, drainfield
was not collapsed – well structured
Stone aggregate: no structure ; collapses on
excavation
APPEARANCE OF AGGREGATE:
Tire chips: intact, not pitted; covered in a “ fuzzy
beige biofilm”; Wires oxidized, almost gone.
Stone aggregate: fairly clean — no attached biofilm
BIOMAT UNDERNEATH THE AGGREGATE:
Tire chip trenches: well-formed biomat trench
bottom — thick (several mm) black sheet of biofilm;
somewhat intact
Tire chips: intact, good separations, covered in a “
fuzzy beige biofilm”, Wires oxidized and mostly
gone.
Stone aggregate: fairly clean — no attached biofilm
Stone aggregate trenches: well-formed biomat —
very thin (mm) dark beige/black
BIOMAT UNDERNEATH THE AGGREGATE:
Stone aggregate systems:
I . Normal trenches — no protozoa or metazoa
Normal trenches small protozoa — later in cultures
System with effluent in trenches — no protozoa or
metazoa
Tire chip trenches: well-formed biomat trench
bottom — black
Stone aggregate trenches: well-formed biomat —
dark
MACROBIOLOGY:
Tire chip trenches: No protozoa; Nematodes in
abundance
Stone aggregate trenches: No protozoa or
nematodes
B. South Carolina Septic Systems
(installed according to S.C. rules):
Drain line installed directly on soil, then aggregate,
covered geotextile fabric. Tire chip systems are
widely used in Horry County, SC. Sampled near
Conway, SC. — Mobile Home Park with both types
MACROBIOLOGY:
Tire chip systems sampled —
System with effluent in trenches — no protozoa or
metazoa
Normal System : Abundant forms:
protozoa — three types of ciliates
metazoa — oligochaetes (aquatic /segmented
worms)
(three types at least — maybe some parts . . .)
metazoa — nematoda (roundworms) somewhat
abundant
metazoa — insect larva (Psychodidae — filter fly/
drain fly)
77
The Role of Soil Scientists
in
On-Site System Permitting
By Milton S. Heath, Jr.
Introduction
Last year, John Williams asked me to talk to
you about your interest in a larger role for soil
scientists in the permitting process for on-site
systems. He was kind enough to renew the
invitation this year, and I am glad to be able to be
here today. What I am going to do now, as you wind
up this convention, is this:
a) review the current North Carolina permitting
system for on-site systems,
b) review the role that private soil scientists
now play in this field in North Carolina,
c) summarize the ways in which some other
states allow private soil scientists to play a larger
role in this area, and finally
d) leave you a few thoughts for your
information as you consider whether to try to lead
North Carolina towards the kind of privatization that
is underway in some other states.
With respect to the situation in other states, I
owe all I know about this subject to John Williams,
who kindly assembled for me a large package of
samples from other states — of their changing laws
and regulations. This saved me hours in the library.
Thank you, John!
The Existing N.C. Permit System
Many of you are at least as familiar as I am with
the existing North Carolina on-site permit system,
but let me summarize it briefly so that we can all
start from the same page. North Carolina has a
classic, three-step permitting system, largely locally
administered: 1) the improvement permit, 2) the
authorization, and 3) the operating permit, at the
end of the process. The role of the local
environmental health specialist (or sanitarian) is
central to the process.
The only person who has legal authority to make
permit decisions and issue permits is a specialist
authorized by the state to administer the on-site
permit. Of course, the specialist, along with soil
scientists, are also keys to the inspection process.
Neither the local health director, the local
environmental health supervisor, nor any of the
state people has a role here (other than general
supervision). In the final analysis, anything that is
done to expand the private soil scientist’s role is
going to affect local specialists more than anyone
else — I know you won’t forget that or discount it.
In North Carolina, there is a State Supreme
Court decision verifying that North Carolina defines
the on-site permitting process to exclude preliminary
evaluations — anything preliminary to the original
improvement permit decision and the inspections
that feed in to that decision. That means that
preliminary evaluations, or whatever you choose to
call them, are not part of the official local
government decision-making process. (We know of
exceptions, but that’s the general rule.)
It is good news for health departments and for
private soil scientists that most local health
departments are not into the preliminary evaluation
because this opens up business for private soil
scientists. It enables you to focus on making that
site evaluation for your landowner or developer
client.
Granted, you may have some frustration with
duplication of efforts, but that kind of goes with the
territory. You have done your duty if you focus on
your obligation to your client. Every effort should be
made to encourage local health departments to
respect the legitimate preliminary work of the
Milton S. Heath, Jr., Assistant Director, Institute of Government, UNC, Chapel Hill, NC
Published in Soil Science Society of North Carolina Proceedings, Vol. XLVI (2003)
78
private soil scientist, and that should be an ongoing
objective of this process of rethinking the overall
picture. Enough of that!
The Current Work of Private Soil
Scientists in North Carolina
In addition to consulting with landowners and
developers in the preliminary evaluation phase of
siting systems, private soil scientists in North
Carolina currently are called upon to apply their
skills in a variety of other circumstances. A group of
experts consulting the N.C. Division of
Environmental Health recently compiled a list of
these activities that includes among other things
•
•
•
•
preliminaries and large systems,
water table determinations,
innovative systems, and
permit processing and appeals.
Of course, there is more (such as texture
analysis, referrals from local health departments,
laboratory analysis, and identifying rights of way),
but this gives us a good start — you can fill in other
activities from your own experience. The overall
message is obvious — there is a lot of work for soil
scientists, working independently or together with
engineers and other professionals.
The Role of the Soil Scientist in
Other States
I haven’t surveyed the literature, but it is
apparent to me from the package that John Williams
gave me that the dividing line drawn by North
Carolina between the usual activities of private soil
scientists and local environmental health specialists
is not unusual. Obviously, a number of states follow
the N.C. pattern.
There is, however, activity underway in some
states to enlarge the role of private soil scientists
and other professionals in on-site work. From the
material that John gave me, I can see that in one or
more states, there are recent statutes or rules that
expand the role of private professionals on the
review and evaluation of sites for on-site systems.
• In some states, this group of private
professionals includes soil scientists, and in others,
the group is limited to engineers and the like.
• More than one state has designated a
category of authorized on-site evaluators (AOSEs),
usually certified or licensed, who are authorized to
perform site evaluations and related functions.
Some AOSEs are allowed also to assist in system
design (though not to do the work of engineers).
• There is enough talk of a “two-track”
permitting system that allows landowners the choice
between a health department permit and all AOSE
permits that I think it must exist in some sense,
even if the statutes are not clear. There may be
some cases where AOSEs actually issue the permits,
but I haven’t seen those words in a statute yet.
A Work in Progress
Dr. Linda Sewall, head of the N.C. Department
of Environmental Health in DENR, has organized a
working group to evaluate suggestions for
expanding the role of private soil scientists in on-site
review and approval. The group is having a series of
meetings to look into privatization proposals, with
potential legislative implications. (I should make it
clear that new state legislation would be required in
North Carolina to change the current system.)
The working group is sifting ideas and
contemplating more meetings. This is, in short, a
“work in progress” by a typical, mixed, state-andlocal group, with other stakeholders also on board.
I have an early checklist of issues to be
examined that includes at least these:
• How far should privatization go if it is a reality:
through preliminary evaluations? through final site
evaluations? through approval of project design or
even into permitting?
• A key issue to be examined involves the impact
of any changes on local health departments. They
are the heart of the delivery system for
environmental public health in North Carolina. Their
needs must be seriously considered, and if
experience is any guide, they will be.
• You can add to my list this one: some hard
questions need to be asked about the wisdom or
propriety of assigning regulatory responsibility over
public health matters to private citizens whose
primary obligation must be to their clients.
After a year like 2002 where every day there are
new headlines about the disastrous effects of
conflicts of interest in the business sector, discretion
may be the better part of valor for those who are
seeking to privatize traditional regulatory activities.
(Over breakfast today, I glanced at the New York
Times, and there was another new story about a
husband and wife who are under SEC investigation
— she a successful securities analyst, he a hedge
fund operator. Could it be that they shared
information illegally?)
79
• Another major issue incidental to any
privatization of on-site work involves liability. We
have had enough bad experience with on-site
related liability of environmental health specialists in
recent years to raise the red flag: anything you get
in the way of privatization is going to take that
liability with it — it will be your liability. The real
problem, however, is more complicated than that.
Nobody knows what new liability problem will arise
for either specialists or private soil scientists if we
slice the pie up differently because there is no
relevant experience to go on.
So, we have a situation calling for speculation or
predictions about liability hitherto unheard of. A lot of
people are going to need good legal advice on sixfigure, seven-figure, eight-figure, or higher liability
risks. Insurance companies may originally absorb
this, but the next step will be premium increases and
revision of contracts. (Remember John Manville and
asbestos. This public health issue goes on and on.
The same New York Times issue has a new story on
multi-billion dollar increases required of companies
like Travellers Insurance for a new generation of
asbestos claims.)
I hope that this is enough to give you the flavor
of what’s going on and what may follow. I want to
leave you with one request and a legislative strategy
suggestion. The request is that you give some
thought to what sorts of useful, productive changes
might be made that fall short of privatization but
would respond to some of the concerns of private
soil scientists. Pass these ideas along to John, if you
will.
By way of legislative strategy, I suggest that if
you want legislative change, you should put together
a package of ideas that has at least two separate
phases:
• Phase One would incorporate modest policy
changes on which consensus might easily be
reached;
• Phase Two would incorporate more substantial
changes, such as privatization, into a second bill
that you would not expect to be seriously considered
until a later legislative session. You might even want
to let Phase II wait until some time has elapsed to
assimilate the Phase I changes.
This kind of strategy has a pretty good track
record for success.
80
POSTERS
Subsurface Movement of Phosphorus
Phosphate Adsorption on Hematite
Lee, J.A. (corresponding author), Graduate Student,
NCSU Soil Science Dept., Raleigh, NC
Osmond, D.L., Soil Science Specialist and Asst.
Professor, NCSU Soil Science Dept., Raleigh, NC
Khare, N. (corresponding author), Graduate Student,
NCSU Soil Science Dept., Raleigh, NC
Wang, S.L., Research Assistant, NCSU Soil Science
Dept., Raleigh, NC
Hesterberg, D.L., Associate Professor, NCSU Soil
Science Dept., Raleigh, NC
Subsurface movement of dissolved P is not
completely understood. For many years it was
thought that P did not move except with eroded soil
particles. Subsurface soil test data suggest
otherwise. An important component of subsurface
movement of P is the seasonal high water table in
some soils. If seasonal high water tables are held
long enough, soils can undergo reducing conditions.
Under reduced conditions, Fe can disassociate
from P, allowing P to convert to a dissolved form.
Once the soil water table is lowered through
drainage, soil P can be held tightly by the soil once
again. This leads to two questions: 1) how much P
enters the soil solution each time reduction occurs,
and 2) how much of this P will move with the soil
water via subsurface movement and eventually gain
access to surface water.
The behavior of P under reduced and oxidized
conditions will be studied for four soil types (organic,
mineral-organic, mineral Coastal Plain loams, and
sandy) and three nutrient sources (commercial
fertilizer, swine effluent, and poultry litter). Half of
the soil columns will be continuously drained with
the remaining columns remaining undrained for
extended periods of time. The aqueous solutions
from each soil column will be analyzed for total P,
ortho-phosphate (PO4), nitrate (NO3), reduced iron
(Fe2+), aluminum (Al), and dissolved organic carbon
(DOC).
Reduced soil conditions tend not to have an
effect on soil Al, but soil Al concentrations need to
be determined because Al can retard the movement
of P in the soil. Reduced Fe2+, Al, P, and DOC
concentrations from soil solutions will be used to
create a relation between subsurface movement of
P under reduced and oxidized conditions. The raw
data from the study will be compared against the
leaching component in the Phosphorus Loss
Assessment Tool (PLAT); this information will be
used to validate the PLAT model’s accuracy when
predicting the subsurface movement of P for the soil
types being studied.
Phosphate interactions with oxide surfaces are
important for understanding phosphorus
contamination and bioavailability. In soils, aluminum
and iron oxides are primarily responsible for the
adsorption of phosphate. However, the mechanisms
of phosphate reactions with oxide surfaces are still
poorly understood. In this study, phosphate
adsorption on hematite was investigated using
adsorption experiments, XANES and ATR-FTIR
spectroscopy. The adsorption isotherms of
phosphate were obtained at pH 4 to 10, and the
maximum adsorption of phosphate decreased as the
pH increased. The XANES and ATR-FTIR spectra of
phosphate adsorbed on hematite were obtained insitu at different surface concentrations and pH
values. The ATR-FTIR results indicate the
predominant formation of inner sphere bidentate
complex, and XANES spectra reveal no formation of
iron phosphate.
Degree of Phosphorus Saturation of Selected
Soils of North Carolina
Johnson, A.M., Graduate Student, NCSU Soil
Science Dept., Raleigh, NC
Osmond, D.L., Soil Science Specialist and Asst.
Professor, NCSU Soil Science Dept., Raleigh, NC
The degree of soil phosphorus saturation (DPS)
represents a significant improvement over soil test
phosphorus (STP) alone because it accounts for
both the amount of sorbed phosphorus and the soil’s
capacity to continue to sorb additional P. Therefore,
DPS is better able to predict potential soluble P loss
across different soil types. Acid ammonium oxalate
extractable iron and aluminum have been shown to
be correlated to soil P sorption capacity because
oxalate extracts the active, or amorphous, forms of
iron and aluminum.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
81
The objectives of this study were to determine
DPS of soils from across North Carolina and to
examine how well North Carolina’s Phosphorus Loss
Assessment Tool (PLAT) is predicting P sorption
capacity. In the present version of PLAT, it is
assumed that the amount of P sorbed will increase
linearly with STP. However, STP does not account
for the fact that the P-binding strength of soils will
decrease with increasing P loading as the soil’s
capacity to sorb additional P is diminished. Major
soil types were sampled from 0 to 32 inches in 4inch increments. P-sorption capacity and DPS were
measured by the ammonium oxalate method.
Results and implications will be discussed.
Method for Continuous Collection of Soil
Solution for Phosphate Analysis
Nelson, N.O. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Mikkelsen, R., former Associate Professor, NCSU
Soil Science Dept., Raleigh, NC
Porous plates or cups are commonly used to
collect soil solution samples in field studies or from
intact soil columns. The choice of material for the
porous plate is important because some materials
commonly used may adsorb soil solution
constituents such as P or metals. An alternative to
using a porous plate is to use a membrane filter with
a known pore size and bubble point. The objective
of this study was to evaluate the utility of
polyethersulfone membranes (pore size 0.45 um
and bubble point greater than 0.2 Mpa) for the
extraction of soil solution in field studies and intact
soil columns for phosphate analysis.
Polyethersulfone membranes (47-mm diameter)
were inserted in reusable polysulfone membrane
holders that were modified to act as small
lysimeters. Lysimeters with 0.01 Mpa vacuum
collected soil solution between 0 and -0.004, -0.010,
and -0.012 Mpa soil moisture tension in loamy
sand, sandy loam, and sandy clay loam soils,
respectively. Lysimeters continued to hold a vacuum
to -0.077 Mpa soil moisture tension. Preliminary
results from membrane lysimeter operation in a
long-term field study and column leaching study will
also be presented.
Phosphorus Accumulation in North Carolina
Piedmont Soils Receiving Animal Waste
Applications
Yarborough, T.K. (corresponding author),
Agronomist, NCDA&CS Agronomic Division,
Raleigh, NC
Mikkelsen, R.L., former Associate Professor, NCSU
Soil Science Dept., Raleigh, NC
Stucky, J.M., Associate Professor, NCSU Botany
Dept., Raleigh, NC
In the Piedmont and Mountain regions of North
Carolina, clayey-textured soils occupy the landscape
where dairy and poultry farms are major agricultural
enterprises. There is increasing concern over P
movement to surface waters, particularly via
subsurface pathways, and limited information exists
on subsurface P movement in clay soils. This
downward P movement can be associated with
potential eutrophication of surface waters. The
extent of P leaching depends on many factors,
including the history of P application, soil physical
properties, rate of application, surface land
management, and rainfall duration and intensity.
Based on previous soil test data from poultry
and dairy operations in ten counties, 42 sites were
selected where Mehlich-3 P concentrations at the
surface exceeded 120 mg dm-3 (240 kg/ha). Soils
were characterized to a depth of 90 cm in 10-cm
increments for Mehlich-3 extractable P
concentrations and particle size distribution. The P
concentration in the 42 sites ranged from 95 to 1286
mg dm-3 (194 to 2722 kg/ha) of Mehlich-3
extractable P in the surface 10 cm.
Clay content ranged from 2% in the surface to
69% in the subsurface. Preliminary results indicate
that clay content, years of application, weight per
volume, Mehlich-3 Fe content, and soil
management group were significant variables
controlling downward P movement. This research
has established the extent of P movement in
Piedmont soils and identified sites where P leaching
is a concern and requires closer investigation.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
82
Determining the Effectiveness of a Naturally
Revegetating Riparian Buffer
Effectiveness of Shrub Buffers on Nitrate-N
Removal
Smith, T.A. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Osmond, D.L., Soil Science Specialist and Asst.
Professor, NCSU Soil Science Dept., Raleigh, NC
Gilliam, J.W., WNR Professor, NCSU Soil
Science Dept., Raleigh, NC
Moorman, C.E., Assistant Professor, NCSU
Forestry Dept., Raleigh, NC
Stucky, J.M., Associate Professor, NCSU Botany
Dept., Raleigh, NC
Wafer, C.C. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Osmond, D.L., Soil Science Specialist and Asst.
Professor, NCSU Soil Science Dept., Raleigh, NC
Riparian buffers are one of several agricultural
best management practices used to reduce nonpoint
source pollution and enhance habitat diversity. The
USDA Natural Resources Conservation Service
offers cost-share assistance to landowners for buffer
installation, provided that specific tree numbers and
species are planted. It is unknown whether these
planted buffers function more effectively than
streamside areas allowed to revegetate naturally.
This study examines the ability of naturally
occurring riparian buffers to reduce groundwater
nutrient concentrations and to support wildlife. The
primary study site is a streamside buffer zone where
previous research determined the buffer width was
insufficient to prevent high nitrate concentrations
from entering adjacent surface waters. Landowners
increased the buffer width by leaving the area
uncultivated, thus allowing a naturally revegetated
grass and shrub buffer to form. Buffer functions are
being assessed by comparing groundwater nutrient
concentrations in this revegetated system with the
same area prior to buffer widening. In addition, the
occurrence of breeding songbird territories in this
natural system is being compared with a similar
planted buffer system. Preliminary results indicate a
general decrease in nitrate concentrations flowing
through the widened buffer system, and a greater
occurrence of avian territories in the natural versus
planted buffer area. If the performance of these
natural buffers is equivalent to that of the more
costly and difficult to establish planted buffers,
streamside areas could be converted to functional
riparian zones by leaving the land uncultivated.
Elevated nitrate concentrations in the Neuse
River Basin, NC, are a major contributor to
decreased water quality. This work is being
conducted to evaluate the ability of shrub buffers to
remove nitrate N from groundwater before entering
surface waters. Shrub buffers were created by
allowing native vegetation to grow between crop
fields and drainage ditches. Three, 15-foot-wide
buffers and one 30-foot-wide buffer were studied.
Shallow (2–3 feet), intermediate (7–8.5 feet) and
deep (9–11 feet) groundwater sampling wells were
installed in each buffer, adjacent to and 15 feet from
each ditch. Additional wells were installed 30 feet
from the ditch in the 30-foot buffer. Samples were
collected monthly and analyzed for nitrate N.
Groundwater data show that more nitrate N is
removed in the 30-foot buffer than in the 15-foot
buffer. Eight redox probes were installed adjacent to
each set of wells (5 probes, 2.5 feet deep; 3 probes,
5 feet deep). Redox potentials and groundwater data
indicate that the nitrate-N removal is related to
denitrification.
Evaluation of the Realistic Yield Expectations of
Soil Map Units in the North Carolina Coastal
Plain
Lohman, M.M. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
White, J.G., Assistant Professor, NCSU Soil Science
Dept., Raleigh, NC
Osmond, D.L., Soil Science Specialist and Asst.
Professor, NCSU Soil Science Dept., Raleigh, NC
Realistic Yield Expectations (RYEs) have been
developed in North Carolina to assist in site-specific
farming decisions that will improve nitrogen-use
efficiency and reduce nitrogen contamination of
groundwater and surface water, especially in the
Neuse River Basin. We conducted this study to
determine whether correlations exist between RYEs,
actual yields, soil map units, and soil test results.
Yield data have been collected for three site years in
two Coastal Plain fields. An intensive soil survey of
the fields was completed in 2002 and compared to
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
83
information in the 1974 Wayne County soil survey.
Intensive soil sampling from 0 to 0.2 m was
conducted at 343 sites on a 21.3-m equilateral grid
spanning 14.74 ha in the adjoining fields. These
samples were analyzed and used to map the spatial
distribution of P, K, and lime requirement. Soybean
(Glycine max [L.] Merr.) and wheat (Triticum
aestivum L.) yield maps will be correlated with soil
test results, soil map units, and their associated
RYEs. We will use the results of the yield map
analysis and soil tests to evaluate RYEs and to help
optimize strategies for sampling and management
to improve N-use efficiency and minimize N loss.
Nitrogen Rates and Realistic Yield Expectations
for Cotton in Northeastern North Carolina
Nixon, W.T. (corresponding author), Regional
Agronomist, NCDA&CS Agronomic Division,
Raleigh, NC
Walls, F.R., Asst. Director, NCDA&CS Agronomic
Division, Raleigh, NC
Messick, J., Field Services Section Chief,
NCDA&CS Agronomic Division, Raleigh, NC
Crozier, C.R., Extension Specialist, V.G. James
Research & Extension Center, Plymouth, NC
Reich, R.C., Director, NCDA&CS Agronomic
Division, Raleigh, NC
Boone, P., District Conservationist, USDA-NRCS,
Winton, NC
Studies were conducted over a two-year period
to evaluate nitrogen rates calculated from realistic
yield expectations (RYEs) for cotton on various soil
types in northeast North Carolina. Many producers
apply more nitrogen to cotton fields than current
nutrient management software indicates is necessary.
Treatments in 2001 consisted of a check treatment
of only starter nitrogen, the RYE-calculated nitrogen
rate (RYE-rate), and the RYE-rate + 30 pounds/acre
additional nitrogen. This test was conducted on
three soil types and in four locations.
Trends in this test showed no response to
additional nitrogen beyond the RYE-rate on sandier
soil types. However, significant increases in yield of
cotton were observed with additional nitrogen on
fine-textured soils in continuous cotton. In 2002,
three sites were selected each having a Craven soil
type (fine textured) and cotton as the previous crop
to study the response to nitrogen rates. In one of the
three sites, yields were significantly higher with the
additional nitrogen. Yields, leaf nitrogen data, and
cotton grade data will be presented.
Using 15N-Labeled Swine Effluent to Determine
Nitrogen Use in Soybean
Allen, M.B. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Mikkelsen, R.L., former Associate Professor, NCSU
Soil Science Dept., Raleigh, NC
Soybean is commonly overlooked as a potential
receiver crop for anaerobic swine effluent due to its
ability to fix nitrogen. The objective of this
experiment was to determine the uptake of swineeffluent-derived nitrogen by soybean. Swine effluent
was spiked with 15N-enriched ammonium sulfate in
order to attain a final 15N enrichment of 5 atom %
15N. The enriched effluent was applied six times at
weekly intervals to nodulating and nonnodulating
soybean growing in one-meter lysimeters. Additional
lysimeters with nodulating and nonnodulating
soybean received no applications of effluent.
Leachate was collected on a weekly basis and
analyzed for 15N and total N. Soybeans were
harvested after six weeks and analyzed for 15N and
total N. Nodulating soybeans that received effluent
applications contained higher tissue N concentrations
compared to unfertilized controls. The amounts of
effluent N taken up by nodulated and nonnodulated
soybeans were not significantly different. On
average, 36.6% of the N in the nodulated soybeans
came from the effluent. N-fixation was not
completely inhibited at the N application rate in the
experiment and accounted for 61.6% of the N in the
nodulated soybeans that received effluent
applications. These results indicate that soybean
can serve as an N receiver crop when swine effluent
is the N source.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
84
Using Remote Sensing for In-Season Nitrogen
Application Decisions for Corn in North Carolina
Sripada, R.P. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Heiniger, R.W., Ext. Crop Science Specialist, V.G.
James Research & Extension Center, Plymouth, NC
White, J.G., Assistant Professor, NCSU Soil Science
Dept., Raleigh, NC
Crozier, C.R., Ext. Soil Science Specialist, V.G.
James Research & Extension Center, Plymouth, NC
Weisz, R., Extension Specialist, NCSU Crop
Science Dept., Raleigh, NC
Burleson, J.M., former Graduate Student, NCSU
Crop Science Dept., Raleigh, NC
There is an increasing need for faster and more
accurate methods to determine supplemental
nitrogen requirements for corn. The objective of this
study was to develop a methodology for predicting
the in-season N requirements for corn at V7 and VT
stages using aerial color infrared photography. Field
studies were conducted at six, two, and three
locations during the 2000, 2001, and 2002 growing
seasons, respectively. The treatments in these
experiments consisted of various N rates applied at
planting and at the V7 and VT growth stages.
Aerial color infrared imagery was obtained for
each of these sites at V7 and VT. Significant yield
responses were observed to increasing N applied at
planting. Significant increases in yields were
observed in response to increases in N application
rates at V7 and VT. Results indicate that better
prediction of economic optimum N rates can be
obtained with relative spectral indices rather than
individual spectral bands or absolute indices
measured at VT. Spectral reflectance of corn
measured using the Green Normalized Difference
Vegetation Index and Green band relative to high N
calibration strips can be used successfully to predict
optimum sidedress N at VT and V7, respectively.
Effect of Small Grain Cover Residue on No-Till
Pumpkin Production
Overstreet, L.F. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Hoyt, G.D., Professor & Ext. Soil Science Specialist,
MHCREC, Fletcher, NC
Reducing tillage in pumpkin production systems
necessitates special considerations by growers.
Cover crop selection is important because different
covers provide specific benefits and concerns.
Choosing a grass cover crop (i.e., rye, barley,
wheat, or triticale) will provide adequate mulch
during the summer growing season but will require
more nitrogen than is recommended for
conventional plowed culture. Legume cover crops
(i.e., crimson clover, hairy vetch, A. winter pea) will
provide less mulch during the summer but will
decompose easily and provide nitrogen for the
pumpkin crop.
No-till pumpkin yields have been very promising
with longer season pumpkin yields being equal to
those of conventionally plowed systems. Varieties
with a shorter growing season may yield less in a
no-till system than with black-plastic, plowed culture.
This is the case because conservation-tilled soils
are cooler, reducing early season growth.
In this study, two varieties of pumpkin (‘Oz’ and
‘Magic Lantern’) were sown into 13 different covers
to examine the effect of cover crop on pumpkin
yield (pounds per acre and number of fruit per acre)
and size. Pumpkins were seeded on a 6-foot–
between-row and 3-foot–in-row spacing. Current
experiments have shown little differences in yield
with various small grain residues, indicating that any
small grain will work effectively for pumpkin
production. Fruit quality is very good in this system
due to the position of the fruit on top of the residue
during the summer as opposed to bare soil.
Stratigraphy of a North Carolina Bay Using
Ground-penetrating Radar
Szuch, R.P. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
White, J.G., Assistant Professor, NCSU Soil Science
Dept., Raleigh, NC
Vepraskas, M.J., Professor, NCSU Soil Science
Dept., Raleigh, NC
Doolittle, J.A., Research Soil Scientist, USDANRCS-NSSC
Zanner, C.W., Asst. Professor, Univ. of Nebraska
School of Natural Resources, Lincoln, NE
Paugh, L., Environmental Supervisor, N.C. Dept. of
Transportation, Raleigh, NC
The N.C. Dept. of Transportation plans to
restore Juniper Bay for wetland mitigation credit.
Knowledge of stratigraphy should aid in the
restoration effort by showing where clayey soils may
act as aquitards. Depth, extent, and continuity of
clayey soils are being investigated using groundpenetrating radar (GPR) with a 120-MHz antenna. A
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
85
lift method has been developed that clearly
delineates the soil surface on GPR traces. Complex
stratigraphy and high spatial variation in soil
properties have caused problems with common
GPR calibrations methods. Use of a depth-scanning
time equation or use of different wave velocities for
organic versus mineral soils may yield more
accurate GPR interpretations.
Agriculture Impacts on Soils of a Drained
Carolina Bay
Ewing, J.M. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Vepraskas, M.J., Professor, NCSU Soil Science
Dept., Raleigh, NC
Juniper Bay is a 296-ha Carolina Bay in Robeson
County, NC, that has been drained and in agricultural
production for up to 30 years. It is now being restored
back to a wetland. The objective of this work is to
describe the soil morphological, chemical, and
physical properties to quantify the degree that the
soils have changed through agriculture.
Twenty-six paired soil pits on a randomly placed
equilateral grid were described and sampled in
Juniper Bay. Three undrained bays were evaluated for
a comparison. Principal changes include increases in
bulk density, increases in exchangeable calcium (Ca)
and phosphorus (P), increases in pH, and decreases
in organic carbon.
Ca and P have moved through the soil profile in
Juniper bay to depths of 100 cm after 30 years of
application. Tillage and burning have created a strong
granular structure in Oap horizons that originally were
massive in structure. Drainage and land shaping has
reduced the thickness of the organic surface by 80 cm
through shrinkage and increased oxidation.
Spatial Patterns of Soil Carbon in Forest Soils of
the Lower Coastal Plain of North Carolina
Anderson, E.S. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Thompson, J.A., Assistant Professor, NCSU Soil
Sci. Dept., Raleigh, NC
Kolka, R.K., Project Leader, USDA Forest
Service, MN
Understanding the carbon cycle is one of the
most difficult challenges facing scientists studying
the global environment. Forest ecosystems of North
America are of particular interest because of their
ability to provide long-term soil carbon storage in
both forest vegetation and soils. Approximately 40%
of the total global C inventory resides in forest
ecosystems, with approximately 60% of forest
ecosystem C residing in soil organic matter.
However, most estimated soil C inventories are
based on means extrapolated from broad categories
of soils and vegetation on a regional scale.
Better analysis and forecast of spatial patterns
of soil properties, such as soil C, is important for
sustainable land management. Furthermore,
understanding spatial patterns in forest soil C may
result in future development of techniques for
conserving and enhancing terrestrial C pools.
Topographic-based spatial models derived from
geographic information systems (GIS) may
potentially improve spatial predictions of soil
properties, including forest soil C pools.
The objective of this study is to develop an
explicit, quantitative, and spatially realistic model of
soil C for a 32,500-ha forest ecosystem located
entirely within the bounds of the Hofmann Forest in
the lower Coastal Plain of eastern North Carolina.
The soils of the Hofmann Forest are predominately
poorly to somewhat-poorly drained Saprists, Aquults,
and Aquepts. Preliminary examination of soil survey
information indicates a topographic influence on
spatial patterns of soil C, with C accretions occurring
in interfluves located furthest from major drainages.
An extensive, nondeterministic sampling
strategy will be used to assure adequate
representation of silviculture and vegetation
regimes within the Hofmann Forest. Samples will
be stratified by vegetation (natural pocosin, natural
pine, and plantation pine) and subclassified by
stand age (plantation pine only) and distance from
major drainage. Soil samples taken to a depth of
1 m will be analyzed for bulk density, total soil C,
and organomineral and labile fractions of soil C. A
split-sampling technique will be employed, with
75% of the samples used for model training and
25% used for model validation.
Spatial models of soil C are being developed and
tested around two hypotheses: 1) spatial patterns of
soil C on a landscape scale are predictable by models
based on pedological relationships displayed by
topographic variation, and 2) spatial soil C storage
patterns of forest soils are affected by the methods of
forest management. Spatial models will be integrated
across the landscape of the Hofmann Forest, and soil
C will be quantified on an areal basis using GIS. We
present methodologies and preliminary results.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
86
Updating WATERSHEDSS: A Web-based
Decision Support System for Best Management
Practice Selection
Hayes, S.A. (corresponding author), Graduate
Student, NCSU Soil Science Dept., Raleigh, NC
Osmond, D.L., Soil Science Specialist and Asst.
Professor, NCSU Soil Science Dept., Raleigh, NC
WATERSHEDSS (WATER, Soil, and HydroEnvironmental Decision Support System) is a Webbased source of information for the identification of
water quality problems and the selection of
appropriate best management practices (BMPs).
The objective of WATERSHEDSS is to transfer
water quality and land treatment information to
watershed managers and land owners to assist in
making appropriate land management decisions for
improved water quality. With user-supplied
information, WATERSHEDSS will assess and
evaluate sources, impacts, and potential
management options for control of nonpoint source
(NPS) pollution in a watershed. The system is
comprised of three components: 1) an educational
component, containing detailed information and
references on NPS pollutants and sources; 2) the
watershed assessment and evaluation; and 3) an
annotated bibliography of NPS literature.
WATERSHEDSS, developed in 1995, is being
updated with new materials, regulations, standards,
and photographs.
A Nutrient Management Decision Support
System for the Tropics: NuMaSS
Osmond, D.L. (corresponding author), Soil Science
Specialist and Asst. Professor, NCSU Soil Science
Dept., Raleigh, NC
Smyth, T.J., Professor, NCSU Soil Science Dept.,
Raleigh, NC
Yost, R.S., Professor, University of Hawaii
Hoag, D.L., Professor, Colorado State University
Branch, W., Private Consultant, NC
Wang, X., University of Hawaii
Li, H., Research Associate, NCSU Soil Science
Dept., Raleigh, NC
Soil acidity and nutrient deficiencies limit crop
yields in most developing countries. The
consequences of poor yields include food
insecurity; economic hardship; further deforestation;
and increased soil exposure, erosion, and
downstream pollution. NuMaSS (Nutrient
Management Support System) was designed to be
a globally applicable, computer-assisted, integrated
decision support system that will both diagnose and
prescribe appropriate solutions to soil nutrient
constraints.
One of the most novel aspects of NuMaSS is
that it evaluates different fertilizer combinations
from a cost/benefit perspective. This aids producers
in making not only appropriate nutrient
management decisions but also the most costeffective nutrient management decision. The
project was developed by a multi-disciplinary team
of 16 scientists from four U.S. universities in close
collaboration with investigators from national
agricultural research and extension services,
private voluntary organizations, nongovernment
organizations, and agri-business. The project was
sponsored by the U.S. Agency for International
Development, which supports the Soil Management
Collaborative Research Support Program (SMCRSP).
Review of Farmer’s Attitudes and Experiences
in the Process of Adoption of Best
Management Practices as Currently Proposed
for Critical North Carolina Watersheds
Interagency Committee of
N.C. Dept. of Agriculture and Consumer Services;
N.C. Dept. of Environment and Natural Resources
Division of Soil and Water;
N.C. State University, and
U.S.D.A. Natural Resources Conservation Service
Producers who live in regulated river basins are
often required to use particular best management
practices (BMPs). In some instances, the rationale
for these BMPs does not make sense to producers
and may even cause ill will. The Corn Growers
Association of North Carolina wanted to be
proactive, especially by facilitating dialogue
between agency professionals involved in these
matters and a broad range of farmers across the
state. Their funding of this project allowed us to
conduct personal interviews with 45 farmers across
the state. These included commercial producers of
all major crops and livestock in our state.
Main themes of the interviews were to explore
the farmers’ concepts of BMPs and those being
practiced and their views on the importance and
use of cost share to enhance adoption and proper
use of these practices. The goal of the project was
to help agencies better understand the knowledge
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
87
and attitudes farmers hold toward acceptance
(adoption) of agricultural BMPs. Forty-five farmers
from throughout North Carolina were interviewed
about BMP adoption and the importance of costshare payments through BMP adoption. The results
from this survey are presented.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
88
MINUTES OF THE 2003 ANNUAL MEETING
OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
President Richard Reich called the business
session of the Forty–Sixth Annual Meeting of the
Soil Science Society of North Carolina to order at
1:20 on January 14, 2003, at the McKimmon Center
in Raleigh. President Reich stated that the mission
of the Society is to increase and disseminate
knowledge of the soils of the state and their uses.
President Reich asked if any members were present
who had attended the first Soil Science Society of
North Carolina meeting in 1958. Mr. Ed Karnowski
was recognized as being a Charter member of the
Society and present today. The location of the forms
for professional development hours was announced.
President Reich noted that around 166 people had
preregistered for the meeting along with 40 plus
walk in registrants for a total of 210 participants.
President Reich praised the membership for their
support and participation in the Division meetings
held prior to the business session. President Reich
called on Mr. Phil Tant to serve as Parliamentarian.
President Reich called for comments on the
minutes of the 2002 business meeting. Copies of
the minutes were mailed to the members and
available in the meeting room. A motion was made
by Mr. Roy Mathis and seconded by Dr. Kleiss to
approve the minutes as reported. The motion was
approved by a voice vote.
President Reich called on Treasurer Roberta
Miller-Haraway for the treasurer’s report. Treasurer
Miller-Haraway stated that bank account balance as
of December 31, 2002, was $15,437.95. The Hubert
J. Byrd Memorial Scholarship comprised $2,397.00
of that amount as of December 31, 2002.
Additionally $1,344.50 was received resulting in a
total balance of $3,741.50 in the scholarship fund. A
motion was made by Mr. Robin Watson and
seconded by Mr. Hal Owen to approve the
treasurer’s report. The motion was approved by a
voice vote.
The committee reports followed. The Auditing
Committee composed of Dr. Keith Cassel, Mr. John
Kelly, and Mr. Kent Messick reported first. Mr. Kelly
reported that the books were in order and excellent
shape. The balance as of June 1, 2001, (the start of
the fiscal year) was $13,153.72. The balance at the
end of the fiscal year was $19,414.86. A motion was
made by Mr. Robin Watson and seconded from the
floor to approve the Auditing Committee report. The
motion was approved by a voice vote.
The Continuing Education Committee was
composed of John Gagnon, Vince Lewis, Carl
Crozier, Bill Dunlop, and Ajmal Heshaam. The
committee met this year via email communication.
Mr. Gagnon reported that continuing education has
been listed as a primary item of the Society’s Web
page. NRCS and other agencies have been
contacted concerning opening their training sessions
to nonagency personnel and listing these training
sessions on the Web page. Agency management
responses indicated that logistics of this endeavor
were too complicated to pursue currently. The
committee is looking into the possibility of having a
“bulletin board” listing of pertinent continuing
education opportunities on the Society’s Web page
and will present a proposal to the Executive
Committee in the spring. Mr. Gagnon noted that Dr.
Mike Vepraskas has proposed a class on the Soils of
North Carolina based on last year’s SSSA tour. A
notebook was placed in the rear of the room to allow
the membership to provide continuing education
ideas and suggestions to the Committee.
Catherine Stokes reported for the Editing and
Publishing Committee. The committee is composed
of Catherine Stokes, Bill Marlin, and Sandra
Weitzel. The proceedings from the 2002 meeting
are available from the Web site, http://
agronomy.agr.state.nc.us/sssnc/index.htm. A limited
number of hard copies will be made available for
libraries. The Web site has a complete listing of the
tables of contents from all of the Proceedings since
1958. The index is searchable by author or key
words in the titles. For this year, the committee
hopes to include a complete paper from everyone
presenting an oral presentation. Authors were asked
to provide a hard copy and an electronic copy of
papers presented. Presenters using several charts
or graphs were asked to provide a crisp clean hard
copy suitable for scanning. Abstracts from poster
presentations are needed for the Proceedings. A box
was present at the registration desk for the
collection of these materials.
Dr. Maurice Cook reported on the activities of
the Scholarship Committee. The first recipient of the
Hubert J. Byrd Memorial Scholarship is Ms. Chandra
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
89
Bowden. Dr. Cook acknowledged the work of the
Scholarship Selection Committee composed of
Caroline Edwards, Roy Mathis, Chuck Sopher, Steve
Steinbeck, Jerry Stimpson, and Sandra Weitzel. The
$500 for the scholarship came from the general fund
for this year. The Committee recommended
awarding a $500 scholarship in the coming year
from the general fund of the Society and continuing
to solicit additional funds for the Hubert J. Byrd
Memorial Scholarship. A separate interest-bearing
account will be established for the Hubert J. Byrd
Memorial Scholarship designated for scholarship
purposes with the goal of reaching $10,000 by 2005.
The purpose of the recommendations is to build an
endowment for the scholarship fund as rapidly as
possible to sustain the scholarship for many, many
years. Dr. Maurice Cook made a motion to adopt the
Scholarship Committee report. A second was received
from the floor. Discussion of scholarship guidelines
followed. The motion was approved by a voice vote.
Dr. George Naderman presented the Century of
Soil Science Committee report. Dr. Naderman
reminded the group that hardcopies of the Century
of Soil Science publications would be available for a
fee of $22 to interested parties. Contact Dr.
Naderman this week if interested. Dr. Amoozegar
proposed a motion to charge $25 per copy and use
the proceeds to purchase three additional copies to
be placed in the Soil Science Department, D.H. Hill
Library, and NC A&T Library. Mr. Alan Clapp
seconded the motion. The motion was approved by
a voice vote.
Robert Brown presented the Nominating
Committee report. David Knight and Steve
Stadelman were nominated for the position of
President-Elect. The floor was opened for additional
nominations. A motion was made by Hal Owen and
seconded by John Kelly to close nominations. The
motion was approved by a voice vote. Ballots were
distributed and collected by the Nominating
Committee. The results of the elections are to be
announced the following day. This concluded the
committee reports.
President Reich recognized the members of the
2002–2003 Executive Committee and thanked them
for their hard work. Three Executive Committee
meetings were held. President Reich highlighted the
volunteer request forms available at the registration
table and the revisions made to the registration
forms. Eighteen oral presentations and twenty-four
posters will be presented at the 2003 meeting.
President Reich reported the results of the
Division meetings held earlier today. Dr. Joe Kleiss
will serve as the Divisional Chair for Academics &
Research. Mr. Elwood Black will serve as the
Divisional Chair for Business, Industry &
Consultants. Mr. Steve Bristow will serve as the
Divisional Chair for Public Health. Mr. Richard
Hayes will serve as the Divisional Chair for
Government Agencies. Division meetings will take
place prior to the annual business meeting each
year.
Dr. Joe Kleiss reported on the Soil Judging
Team. He thanked the Society for their support of
the Soil Judging Team. A motion was made by Dr.
Willem Van Eck and seconded from the floor to
provide support of $2,000 to the soil judging team.
The motion was approved by a voice vote.
President Reich asked Mr. Joshua Bledsoe to
update the Society on the North Carolina FFA Land
Judging Career Development event. Mr. Bledsoe
thanked the membership for their support of this
event and recognized Dr. George Naderman, Ms.
Sandra Weitzel, and Mr. Richard Brooks for their
assistance. Approximately 160 students attend the
land-judging event as it travels across the state. Mr.
Bledsoe requested the Society continue their
support of FFA. Mr. Richard Brooks made a motion
to give $1,000 to the FFA Foundation with $300
going to expenses for the 2002 state land judging
contest, $500 as a matching grant to the second
place team towards expenses to attend the national
competition, and $200 earmarked to sponsor the
proficiency award in Environmental Science and
Natural Resources Management and seconded by
Ms. Sandra Weitzel. The motion was approved by a
voice vote.
President Reich called for any other old
business for discussion. There was none.
President Reich moved to new business and asked
the members to review the revisions to the bylaws
as contained in the registration packets. The split of
the Secretary-Treasurer position into two separate
positions was contained in this revision, which
results in adding another member to the Executive
Committee. President Reich reviewed the time
frame of this revision from being approved by the
Executive Committee on September 12, 2002, and
provided to the membership in advance of the
meeting as required. Mr. Roy Mathis made a motion
to accept the revisions in the bylaws to split of the
Secretary-Treasurer position into two separate
positions resulting in an additional member of the
Executive Committee, and the motion was
seconded by Mr. Richard Hayes. The motion was
approved by a voice vote.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
90
President Reich recognized Mr. Clayton Norton.
Mr. Norton discussed providing small cash awards
for first-place ($100) and second-place ($50) posters
that contribute practical research that enhances our
understanding of present technology, processes or
emerging topics as judged by the sponsors. The
awards will be funded by the sponsors and
presented at the Awards Luncheon. Mr. Bob Branch,
Mr. Clayton Norton, and Mr. Don Desha made the
prize selections for 2003. Dr. King made a motion
that the Society allow these awards to occur at the
Annual meeting this year (2003). The motion was
seconded from the floor.
President Reich recognized Mr. Hal Owen. Mr.
Owen reported that a State Chapter of the National
Society of Consulting Soil Scientists was established
this morning and the Chapter will meet at 4:00
tomorrow afternoon. Mr. Owen requested that the
Executive Committee consider how this Chapter
would interact with the Society. President Reich
reminded the membership that Mr. Elwood Black is
the official Chair for Business, Industry, and
Consultants.
A motion was made by Dr. Joe Kleiss to adjourn
the meeting and seconded by Dr. King. President
Reich adjourned meeting at 2:37.
Minutes submitted by Steve Dillon
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
91
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
Audit Committee Report: 7/1/2001 to 6/30/2002
January 8, 2003
The financial records of the Soil Science Society of North Carolina, as maintained by Treasurers Robin J.
Watson from June 30, 2001, through February 28, 2002, and Roberta Miller-Haraway from March 1, 2002,
through June 30, 2002, have been examined and found to be in order, as follows:
GENERAL FUND
Item
Receipt
Disbursement
BEGINNING BALANCE [7/1/2001]
Balance
13,153.72
INCOME:
Membership Fee
Preregistration/Registration Fee
Lunch/Banquet
Vendors
Promotional T-Shirts/Hats
Scholarship
3,105.00
8,600.00
2,217.00
1,350.00
212.00
2,397.00
EXPENDITURES:
McKimmon Center Rental
Show Services Rental
Meals and Social Functions
Speaker and Expenses
Awards
Contribution to Soil Judging Team
Postage, Office Supplies
Printing – Proceedings
Refunds
Wachovia Bank analysis fees
Miscellaneous Expenses
TOTAL
5,313.50
319.50
2,623.81
155.26
183.42
500.00
1,218.87
778.28
135.00
164.22
228.00
17,881.00
ENDING BALANCE [6/30/2002]
D. K. Cassel, Chairman
11,619.86
19,414.86
Kent Messick
John Kelley
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
92
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
2003 COMMITTEES
Executive Committee
Auditing Committee
Aziz Amoozegar, President
Steve Stadelman, President-Elect
Steve Dillon, Secretary
Roberta Miller-Haraway, Treasurer
Joe Kleiss, Academics & Research
Elwood Black, Business, Industry & Consultants
Steve Bristow, Public Health
Richard Hayes, Government Agencies
Richard C.Reich, Past President
Keith Cassel, Chairman
John Kelley
J. Kent Messick
Nominating Committee
Continuing Education Committee
John Gagnon, Chairman
Ajmal Heshaam
Bill Dunlop
Carl Crozier
Vincent Lewis
Robert Brown, Chairman
Perry Wyatt
Alan Clapp
Trade Show Committee (ad hoc)
Awards Committee
Steve Stadelman, Chairman
Richard Brooks
Jerry Stimpson
M. Ray Tucker, Chairman
Roberta Miller-Haraway
Elwood Black
Century of Soil Science Committee (ad hoc)
George Naderman, Chairman
Program & Arrangements Committee
Aziz Amoozegar, Chairman
David Hardy
Richard Hayes
Steven Stokes
Editing & Publishing Committee
Catherine Stokes, Chairman
Bill Marlin
Sandra Weitzel
Public Relations Committee
Tony Jacobs, Chairman
David Knight
Marty Allen
Scholarship Committee (ad hoc)
Maurice Cook, Chairman
Paul Blizzard
Steve Broome
Steve Clayton
Caroline Edwards
John Kelley
Joe Kleiss
Paul Lilly
Roy Mathis
Richard C. Reich, Ex Officio (President of SSSNC)
Chuck Sopher
Steve Steinbeck
Jerry Stimpson
F.R. (Bobby) Walls
Sandra Weitzel
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
93
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
HISTORICAL PERSPECTIVES
SOIL SCIENCE SOCIETY OF NORTH CAROLINA ACHIEVEMENT AWARDS
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
George Naderman
M. Ray Tucker
Aziz Amoozegar
Horace Smith
Ray Campbell
Andy Goodwin
Stephen W. Broome
Kevin C. Martin
Gordon Miner
Joe A. Phillips
Robert L. Uebler
Donald W. Eaddy
J. Paul Lilly
H. J. Kleiss
Keith Cassel
Ernest N. Hayhurst
Robert E. Horton
Paul T. Blizzard
William T. Barnhill
Ray Daniels
Wendell Gilliam
Stanley Buol
Maurice Cook
Joel Cawthorn
Steve Barnes
Bill Pickett
Hubert Byrd
Guy Jones
Walton Dennis
Louis Aull
Roy Tillery
Jack V. Baird
W. G. Woltz
Bill Lamm & W. B. Bartholomew
G. Winchester & R. J. McCracken
S. N. Hawks & E. J. Kamprath
Bryce Younts & W. A. Jackson
Brodie Harrell & J. W. Fitts
Norfleet Sugg & Forest Steele
S. E. Younts & C. B. McCants
E. Goldston & W. W. Woodhouse
J. F. Lutz & W. H. Rankin
E. V. Floyd & A. Mehlich
E. R. Collins & W. D. Lee
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
94
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
ACTIVE MEMBERS, YEAR 2003
Alex Adams
Connie Adams
Mark Allen
John B. Allison
Aziz Amoozegar
Deborah T. Anderson
Edwin Andrews III
Moulton A. Bailey
Larry Baldwin
John Steven Barnes
Thomas Barrett
Kirk W. Becker
James L. Beeson
Elwood Black
Stuart B. Black
Daniel J. Bliley
Paul T. Blizzard
Thomas Blue
Thomas J. Boyce
Bob Branch
Randy Brant
Steve Bristow
Bobby G. Brock
Richard Brooks
Steve Broome
Jeremy Brown
Robert M. Brown
Will Buetow
Stanley W. Buol
Jennifer Burdette
Charles Cahill
C. Ray Campbell
Christopher Scott Carpenter
Kevin Carver
W. Edward Casavant
D. Keith Cassel
Darren N. Cecil
Beth Chagaris
Stephen Chambers
Dolores M. Chandler
Alan Clapp
David C. Clapp
Steve Clayton
Everett Coates
Thomas D. Cochran
Albert Coffey
Stephen Colbert
Walter Cole
Amber L. Coleman
Raymond Coltrain
Maurice Cook
Jim Cooper
David A. Crouse
Stanley Crownover
Carl R. Crozier
John R. Davis
Sam Davis
Daniel Ryan Deel
Don Desha
W. A. Dickerson
Steve Dillon
Timothy L. Donnelly
William Doucette
Billy Dunlap
W.R. Dunlop, Jr.
Donald W. Eaddy
Mike Eaker
Gary L. Easter
Caroline J. Edwards
Ellis Edwards
Steve T. Evans
Justin Ewing
Christy Lynn Faltinosky
Neal C. Floyd
Laura Fortner
Scott Fredrick
John A. Gagnon, Jr.
Jan Gay
J. Wendell Gilliam
Roy A. Goodwin
Dwayne A. Graham
Christopher Greene
Tom Gulley
Steve Gurley
Jason Hall
Roger Hanson
David H. Hardy
Timothy P. Harlan
Mac Haupt
John Havlin
Allen Hayes
Chris Hayes
Richard Hayes
Ernest N. Hayhurst
Ajmal A. Heshaam
Dean Hesterberg
Eric A. Hill
Jonathan Hill
Dwane Hinson
Joseph A. Hinton
Phyllis D. Hockett
Walter Hogg
Ralph Hollowell
Michael Hoover
Robert E. Horton
Lynn Howard
Mark S. Hudson
Sheila J. Hughes
Charles Humphrey
Daniel W. Israel
Tony C. Jacobs
Johnson C. Jenkins
Tim Johnson
Robert S. Jordan
Eugene Kamprath
Ed Karnowski
Barrett L. Kays
John Kelley
Larry King
Joe Kleiss
David T. Knight
George Lankford
Roger Leab
James Lewis
Jason A. Lewis
Vincent Lewis
William Grant Lewis
Ron Lilley
David L. Lindbo
David Little
Everette Lynn
Ted Lyon
Martin E. Mabe
Cathy Machek
Mike Machek
L. Lee Mallard III
Dan Manning
William Marlin
Brett Martin
James A. Martin
Kevin Martin
Roy L. Mathis, Jr.
Dana F. Mayberry
Clifford Mc Cachren
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
95
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
ACTIVE MEMBERS, YEAR 2003 (continued)
David McCloy
Dennis McCoy
Kirk McEachern
Terra McKee
Melanie McKinney
Rich McLaughlin
Steve Melin
Kent Messick
David Meyer
Roberta Miller-Haraway
Albert Mills
Amber Moore
George Naderman
Kevin Neal
Nathan O. Nelson
James Newell
Chris Niewoehner
Clayton Norton
Michael Norton
Kevin Nunnery
Mike Ortosky
Dennis Osborne
Deanna Osmond
Wendell Overby
Hal Owen
Kenneth Owens
Bill R. Patrakis
Carl D. Peacock, Jr.
Roger Pearce
Paul G. Penninger
Carroll Pierce
Ricky Pontello
Sushama Pradhan
Steve Price
Wayne Ragland
Chad Rakes
Richard Reich
John C. Roberts
Ken Roeder
Samuel Ashley Rollans
Todd Rowe
Scott Sanders
Thomas Neil Schmitt
Karl Shaffer
Michael Sherrill
Larry T. Sink
Clark Sizemore
Bruce Smith
Fred Smith
Horace Smith
Tim Smith
T. Jot Smyth
Charles D. Sopher
Hank Sowers
Dan Spangler
Willie Spruill
Steve Stadelman
Miranda Stamper
Steve Steinbeck
Jerry V. Stimpson
Catherine Stokes
Steven Stokes
E. Scott Stone
Robert E. Stott
Brad Suther
Ryan Szuch
Marlene Talley
Phil Tant
Eric Thompson
Jennifer Tredway
M. Ray Tucker
Craig Turner
Danny Turner
Wes Tuttle
Robert Uebler
Willem Van Eck
Jeff Vaughn
Mike Vepraskas
Roy L. Vick
Michael Wagger
George Walker
Bobby Walls
R. Barry Ward
James H. Ware
Robin Watson
Sandra Weitzel
Donald Wells
Jeffery G. White
Gary F. Whitley
Rob Wilcox
John P. Williams
Josh Witherspoon
Yiyi Wong
Brian Wood
Michael Wood
Perry Wyatt
Jerry Yarborough
Kent Yarborough
William Yarborough
Gene Young
Joe Zublena
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
96
PAST EXECUTIVE COMMITTEE MEMBERS
2002
Richard C. Reich, President
Aziz Amoozegar, Steve Dillon, Roberta
Miller-Haraway, Roy Mathis, Alan Clapp,
John Allison
2001
John Allison, President
Richard C. Reich, Robin Watson, Roy
Mathis, Bill Yarborough, John Kelley
2000
John Kelley, President
John Allison, Robin Watson, Joseph Hinton,
Bill Yarborough, George Naderman
1999
1990
Mike Hoover, President
Steve Clayton, Bob Uebler, Steve Barnes,
Debbie Anderson, Andy Goodwin
1989
Andy Goodwin, President
Mike Hoover, Bob Uebler, B. Yarborough,
Steve Barnes, Jerry Stimpson
1988
Jerry Stimpson, President
Andy Goodwin, Bob Uebler, B. Yarborough,
P. Denton (Resigned), Jim Canterberry,
Paul Lilly
George Naderman, President
John Kelley, Robin Watson, Joseph Hinton,
Steve Stadelman, Richard Brooks
1987
J. Paul Lilly, President
Jerry Stimpson, Bob Uebler, R. Rucker,
P. Denton
1998
Richard C. Brooks, President
George Naderman, Aziz Amoozegar,
Mike Ortosky, Joe Zublena
1986
Bob Uebler, President
Paul Lilly, Jack Baird,
R. Tucker, Gordon Miner
1997
C. Ray Campbell, President
Richard Brooks, Aziz Amoozegar,
Mike Ortosky, Joe Zublena
1985
Keith Cassel, President
Berman Hudson (Resigned), Bob Uebler,
Jack Baird, Paul Blizzard, Gordon Miner
1996
Mike Vepraskas, President
Ray Campbell, Steve Hodges, Mike
Ortosky, Dan Bliley
1984
Darwin Newton, President
Keith Cassel, Jack Baird, Paul Blizzard,
Jerry Stimpson, Bob Uebler
1995
Karl Shaffer, President
Mike Vepraskas, Steve Hodges,
Richard Brooks, R. Campbell, Horace Smith
1983
Paul Blizzard, President
Darwin Newton, Jack Baird, Joe Kliess,
Jerry Stimpson, Paul Lilly
1994
Everette Lynn, President
Karl Shaffer, Gordon Miner, Richard Brooks,
Ray Campbell, Horace Smith
1982
Joe Kliess, President
Paul Blizzard, Darwin Newton,
Ernest Hayhurst, Paul Lilly, L. Jackson
1993
Horace Smith, President
Everette Lynn, Gordon Miner, Karl Shaffer,
Richard Brooks, Steve Barnes
1981
Ernest Hayhurst, President
Joe Kliess, Darwin Newton, L. Jackson,
Steve Barnes, Keith Cassel
1992
Steve Barnes, President
Horace Smith, Gordon Miner,
Dennis Osborne, Karl Shaffer, Steve
Clayton
1980
John Nicholaides, President
Ernest Hayhurst, Darwin Newton,
Joel Cawthorn, Steve Barnes
1979
1991
Steve Clayton, President
Steve Barnes, Gordon Miner, Debbie
Anderson, Dennis Osborne, Mike Hoover
Joel Cawthorn, President
John Nicholaides, Ernest Hayhurst,
J. W. Gilliam, Steve Barnes, S. Broome
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
97
PAST EXECUTIVE COMMITTEE MEMBERS (continued)
1978
J. Wendell Gilliam, President
Joel Cawthorne, Ernest Hayhurst,
Bobby Carlile, R. Hoague, S. Broome
1968
Jack V. Baird, President
Fred Cox, Louis Aull, W. Barley,
Ed Karnowski, M. McCants
1977
Bobby Carlile, President
J. W. Gilliam, J. Reeves, R. E. McCollum,
Jim Ware, R. Hoague
1967
C. B. McCants, President
A. Plant, C. Davey, C. Watts, J. Perry
1966
1976
R. E. McCollum, President
Bobby Carlile, J. Reeves, Steve Barnes,
John Carpenter, Jim Ware
J. M. Spain (Elected President)
C. B. McCants (Completed Term)
C. McCants, C. Davey, A. Plant,
J. Perry, S. Younts
1975
John A. Carpenter, President
R. McCollum, J. Reeves, Ed Karnowski,
Steve Barnes, Hubert Byrd, W. Pickett,
Chuck Sopher
1965
S. E. Younts, President
J. Spain, C. Davey, A. Plant, Louis Aull,
E. Kamprath
1964
E. J. Kamprath, President
S. Younts, J. Spain, W. Dickens, Louis Aull,
W. Bartholomew
1963
W. V. Bartholomew, President
E. Kamprath, S. Dobson, J. Sedberry,
J. Watts, N. Sugg
1962
N. L. Sugg, President
W. Bartholomew, S. Younts, A. Baxter,
J. Watts, W. White
1961
W. C. White, President
L. Hunt, S. Younts, A. Baxter,
W. D. Lee, J. Lutz
19581959
J. P. Lutz, President
F. Steele, W. White, K. Shaw, J. Fitts
1974
1973
1972
19701971
1969
Hubert Byrd, President
Chuck Sopher, John Carpenter,
Ed Karnwoski, W. Pickett, C. Willey
Joseph A. Phillips, President
Hubert Byrd, Chuck Sopher, C. Willey,
Ed Karnowski, Louis Aull
Louis E. Aull, President
Joe Phillips, Hubert Byrd, W. L. Barnhill,
B. Nelson
W. K. Collins, President
Louis Aull, Joe Phillips, L. Jackson,
W. L. Barnhill, H. Smith
Fred R. Cox, President
H. Smith, Louis Aull, W. Campbell,
Ed Karnowski, Jack Baird
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
98
CONSTITUTION AND BYLAWS
OF THE
SOIL SCIENCE SOCIETY OF NORTH CAROLINA
PREAMBLE
The following Constitution and Bylaws shall govern the activities of the Soil Science Society of North Carolina.
This Constitution and Bylaws, when adopted, shall supersede and nullify all previous Constitutions and Bylaws of
the Society.
ARTICLE I: Name and Organization
Section 1. The name of the organization shall be: “Soil Science Society of North Carolina”.
Section 2. The organization shall consist of the membership as designated in Article III.
ARTICLE II: Objectives
Section 1. The objectives of the Society shall be to promote the accumulation, dissemination, and utilization of
knowledge pertaining to the soils of North Carolina and to provide a medium for exchange of information by
those interested in Soil Science and in closely related subject matter areas.
ARTICLE III: Membership
Section 1. There shall be six classes of membership as follows:
a. Individual: Persons who maintain active status by payment of annual dues as prescribed in Article IX.
b. Organizational: Any organization that pays dues as specified in Article IX. Each group may designate one
individual who shall have the same rights as an individual member.
c. Sustaining: Industrial and/or other organizations that pay dues as specified in Article IX. Each group shall
designate one individual who shall have the same rights as an individual member. Sustaining members are
those who wish to support the Society financially to an extent over and above that set forth in a and b
immediately above.
d. Active Life: This membership classification is reserved for those individuals who are now retired from their
principal career responsibilities; and who for at least three years prior to retirement were active members of
the Society. These members shall have all the privileges of individual members including attending and
participating in the annual meetings, voting rights, and receiving Society materials and publications. They
shall be exempt for life from payment of annual dues.
e. Honorary Life: This membership classification is reserved for those individuals who throughout their career
have made a lasting impact on Soil Science. This category differs from the Annual Achievement Award in
that it is awarded based on the sum total of the individual's career. Any member can nominate someone for
this membership distinction. The executive board will make the final determination. Recipients shall have all
the privileges of Active Life Members.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
99
f. Student: This membership classification is reserved for those individuals who are now undergraduate or
graduate students in Soil Science or a related field of study. Individuals involved in post-doctorate work are
not included. These members shall have all the privileges of individual members. They shall be exempt from
registration fees.
Section 2. The membership may further participate in the following divisions:
a. Academic and Research.
b. Business, Consulting, and Industry.
c. Public Health.
d. Governmental Agencies.
Divisions will meet during the annual meeting before the Society business meeting. They are to inform
and promote to the general membership the specific interests of the divisional membership. They are
responsible for electing a division chairperson who will serve on the Executive Committee. Divisional
activities are subject to full Executive Committee approval.
ARTICLE IV: Officers, Duties, and Election
Section 1. Officers. The officers of the Society shall consist of a President, a President-Elect, and a SecretaryTreasurer. There shall be an Executive Committee consisting of the President of the Society (Chairperson),
the President-Elect, the Secretary-Treasurer, the most recent past President, and the chairpersons of each of
the four divisions in Article III, section 2, elected by that division membership. Section 4 immediately below
shall apply for non-functioning divisions.
Section 2. Duties of Officers.
a. The President shall preside at meetings of the Executive Committee, at business meetings of the Society,
and at other meetings of the Society as he (and the Executive Committee) may deem appropriate. He shall
appoint the necessary committees as provided for in Article VI and shall have general supervision of all the
affairs of the Society.
b. The President-Elect shall serve as Chairman of the Committee on Program and Arrangements and shall
be generally responsible for preparing the program and making the other necessary arrangements for the
annual meeting.
c. The Secretary-Treasurer shall keep the minutes of the Executive Committee and regular Society
meetings, handle the financial affairs, keep the financial record of the Society, and perform such other duties
as may be appropriate to that office.
d. The Divisional Chairperson shall preside over their respective division meetings. They shall appoint
subcommittees pertinent to the division. Division chairpersons shall report to the President.
e. The Executive Committee shall be empowered to act for the Society between annual or duly called
meetings. It may make recommendations for appointments of ad hoc or standing committees and shall be
empowered to fill vacancies in any office of the Executive Committee until the next regular meeting of the
Society.
Section 3. Election. The President-Elect shall be elected by ballot at the annual meeting of the Society. The
President shall appoint a Nominating Committee. This committee shall nominate at least two candidates for
the office of President-Elect. Other nominations may be made from the Floor. Election shall be by a majority
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
100
of the votes cast. In case no nominee receives a majority on the first ballot, the two receiving the highest
number of votes on the first ballot shall be voted upon in a second balloting The Division Chairperson shall
be elected by procedures established by the division membership.
The President-Elect shall serve in that capacity for one year and then shall succeed to the Presidency for
one year. The elected members of the Executive Committee shall serve for a term of two years, with terms
of office expiring in alternate years. The Secretary-Treasurer shall be appointed by the Executive Committee
and shall serve for a term mutually agreeable to him and to the Executive Committee.
Section 4. Filling Vacancies. If a vacancy should occur in one or more of the offices, or in the Executive
Committee, the remaining members of the Executive Committee shall be empowered to fill the vacancy until
such time as a regular business meeting of the Society shall be convened.
ARTICLE V: Government and Meetings
Section 1. The major business and governmental affairs of the Society shall be transacted at the annual meeting,
or at the other duly called meeting. A majority vote of those present at a duly constituted meeting shall be
required for approval of any and all business matters, except the changing of this Constitution and Bylaws
(See Article X, Section 1). The Executive Committee shall be empowered to act for the Society between duly
constituted meetings.
Section 2. The Society shall hold an annual meeting at a time and place to be determined by the Executive
Committee. Other meetings, conferences, or tours may be arranged by the Executive Committee on their
own initiative or in response to requests from members of the Society.
Section 3. All business meetings of the Society shall be conducted in accordance with Robert’s Rules of Order.
Section 4. The annual business meeting of the Society should provide for the following:
a. Approval of the minutes of the last meeting.
b. Report of the President.
c. Report of the Secretary-Treasurer.
d. Report of the Auditing Committee.
e. Reports from the Division Chairpersons.
f. Old business.
g. New business.
h. Election of President-Elect.
i. Adjournment.
Section 5. A quorum at a meeting of the Executive Committee shall consist of a majority (that is, at least five) of
the members.
Section 6. A quorum at any duly called business meeting of the Society shall consist of at least fifteen percent of
the active membership, with the number of active memberships being certified to by the Secretary-Treasurer.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
101
ARTICLE VI: Committees
To assist in the various duties and responsibilities of the Society, the committees listed below shall be appointed.
Ad hoc or special committees may be appointed as deemed necessary by the President and/or Executive
Committee.
Section 1. Executive Committee. This committee shall consist of the President as Chairman, the President-Elect
and the Secretary-Treasurer, the immediate past President, and four Divisional Chairpersons to be elected as
specified in Article IV, Section 3.
Section 2. Nominating Committee. There shall be a Nominating Committee of three, at least two of whom shall
be past Presidents of the Society, to make nominations for officers as specified in Article IV. Section 1.
Section 3. Committee on Awards. There shall be a committee to select, with the approval of the Executive
Committee, an individual to receive the Annual Achievement Award as specified in Article VII.
Section 4. Program and Arrangements Committee. The President shall appoint a committee on program and
arrangements with the President-Elect to serve as Chairperson.
Section 5. Editing and Publishing Committee. The President shall appoint an Editing and Publishing Committee
to be responsible for editing and publishing the proceedings of the annual meeting and other material as
might be deemed necessary from time to time.
Section 6. Public Relations Committee. The President shall appoint a committee on public relations, the duties of
which shall include the following:
a. Membership: To serve as a liaison and information medium between the Society and prospective new
members.
b. Cooperation: To serve as a liaison between the Soil Science Society and other related societies or
agencies.
c. Necrology: To secure a list of names of any members that might have passed away during the year and to
prepare a suitable memorial statement for them.
d. Resolutions: To prepare resolutions pertaining to any phase of the operations of the Society or otherwise
as the committee may deem pertinent.
Section 7. Auditing Committee. The President shall appoint an Auditing Committee consisting of at least two
members of the Society to audit the Treasurer’s books and to certify as to their correctness. The Auditing
Committee’s report shall be presented at the general business meeting immediately following the report of
the Secretary-Treasurer.
Section 8. Continuing Education Committee. Through this committee, the Society shall sponsor and/or conduct
educational programs of significant interest in soil science and closely related subject matter areas. The
committee shall submit program proposals to the Executive Committee for approval.
ARTICLE VII: Awards
Section 1. The Society has an award in the form of a certificate which can be given for outstanding achievement
in soil science. The work for which the recognition is given may be in research, teaching, extension,
administration, or other; but it must be principally and directly related to soil science. Not more than one such
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA
102
award shall be given per year. None may be given if, in the opinion of the Awards Committee with the
approval of the Executive Committee, there is no worthy candidate in any particular year.
ARTICLE VIII: Publications
Section 1. The Society shall publish the proceedings of the annual meetings in a publication to be designated as
Soil Science Society of North Carolina Proceedings. The Proceedings shall contain the papers presented at
the meeting (with written summaries from poster presentations optional and left to the discretion of the
presenter). Submitted papers shall be a maximum of 5,000 written words or maximum of 10 pages of total
text, double spaced, including tables and references: unless prior clearance is received from the editor of the
Proceedings. The Proceedings shall also contain the minutes of the business meeting, including the results of
the election, a list of the various committees, the citation pertaining to the recipient of the Achievement
Award, and other committee reports and materials as deemed necessary by the Editing and Publishing
Committee with the approval of the Executive Committee.
ARTICLE IX: Dues and Finances
Section 1. Membership dues shall be as recommended by the Executive Committee, with the dues for various
classes of membership as follows:
a. Individual membership - Dues shall be set by the Executive Committee.
b. Organization membership - $50.00.
c. Sustaining membership - $75.00, minimum.
d. Active Life membership - exempt as per Article III, Section 1d.
e. Honorary Life membership - exempt as per Article III, Section 1e.
f. Student Life membership - as per Article III, Section 1f.
Section 2. Dues are payable on a calendar year basis. Dues are expected to be paid prior to or at the time of the
annual meeting. Any dues received after the annual call for dues, and prior to the call for annual dues for the
subsequent calendar year, shall be for that calendar year in which received. New members shall pay dues at
the time of application.
Section 3. To defray cost of the annual meeting, a registration fee will be charged those registering for the annual
meeting. The amount of this fee will be determined by the Executive Committee.
Section 4. Proceedings will be published on the Society's web page. Cost of publishing and maintaining the web
page will be offset by receipts of member's dues and annual meeting registration fees.
ARTICLE X: Amendments
Section 1. This Constitution and Bylaws may be amended by a two-thirds majority vote of the members present
at any duly constituted annual meeting, provided such amendments have first been presented to the
Executive Committee at least thirty days prior to the time of the annual meeting and have been mailed to the
membership at least two weeks prior to the annual meeting.
NOTE: Approved by membership January 15, 2002.
PROCEEDINGS OF THE FORTY-FIFTH ANNUAL MEETING OF THE SOIL SCIENCE SOCIETY OF NORTH CAROLINA