SOIL QUALITY ASSESSMENT
Bob Kremer & Kristen Veum
USDA-ARS Cropping Systems and Water Quality Research Unit
Columbia, MO
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
SOIL QUALITY: functional
capacity of soil to meet defined
human needs by supporting optimal
biological activity and diversity for
economic production of crops and
livestock, regulation of water flow and
storage, and provision of
environmental buffers.
SOIL HEALTH: continued capacity of soil
Missouri
(Menfro silt loam)
as a vital living system whereby plant and
animal growth and environmental quality is
sustained; a holistic approach in which
plant, animal, and human health is promote
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Brazil (‘Oxisol’)
Soil Quality Test Kit - landowner self-assessment of soil quality/soil health
USDA-NRCS, Soil Quality Institute. 2001. Soil Quality Test Kit Guide.
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Quality Assessment
Vital functions:
sustain biological activity, diversity, productivity
regulate/partition water and solute flow
filter, buffer, degrade, immobilize and detoxify organic/inorganic material
store and cycle nutrients within the biosphere
support socioeconomic structure, protect habitat
Soil Processes:
Biological
Chemical
Physical
Indicators:
Soil property measurements that are sensitive to detect changes in the functions or
processes of concern; i.e., sensitive to land management practices
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
“SMAF” site-specific interpretation for soil quality assessment results
• measured soil indicator data (scores) integrated into a “soil
quality index”
• index often correlates with value of other soil properties
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Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
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Quantitative index using algorithms to calculate non-linear
scores for each indicator variable ranging from 0-1
Scores are summed and averaged across indicators
13 available indicators representing 4 soil function groups:
• Physical – aggregate stability, bulk density
• Chemical – EC and pH
• Nutrient – P, K and mineralizable N
• Biological – SOC, microbial biomass-C, β-glucosidase
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
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Uses Site-Specific Characteristics to Parameterize the
Algorithms:
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OM Class (WSA, SOC, β-GLU, P…)
Texture Class (WSA, SOC, BD, K, β-GLU, P…)
Fe2O3 Class (WSA…)
Climate Class (SOC, β-GLU…)
Mineral Class (BD…)
Slope Class (P…)
Weathering Class (P …)
Crop Optima (pH, P…)
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
Water Stable Aggregates Algorithm:
Y= a + b * cos (cx – d)
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d = d1*d2*d3
d1 based on OM class
d2 based on textural class
d3 based on Fe2O3 class
a, b & c are fixed
x = WSA (%)
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
pH Algorithm:
Y = a * exp ((-(x-b)2) / 2*c2)
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a = 1 (fixed)
b = optimum pH§
c = pH range §
x = pH
§ crop
dependent
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
Example using Centralia Plots (3 reps each) – Fall 2010
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Minimum Till Corn – No Till Soy (MTC-NTS)
No Till Corn – No Till Soy (NTC-NTS)
Integrated Crop Mgt - Wheat (cover) - Corn (cover) –
Soybean (ICM-WCS)
Switchgrass (SG)
Cool-season grass/legume (CRP)
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Soil Management Assessment Framework
(SMAF) Soil Quality Index
SMAF Variables Selected (6)
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Soil Phosphorus
Extractable Potassium
Water pH
Bulk Density
Soil Organic Carbon
Water Stable Aggregates
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Centralia SMAF Scores by Cropping System and
Landscape Position
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Centralia SMAF Scores by Cropping System
(averaged across landscape positions)
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Sanborn Field SMAF Example
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Selected SMAF References
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Stott, D.E., C.A. Cambardella, R. Wolf, M.D. Tomer, and D.L. Karlen.
2011. A soil quality assessment within the Iowa River South Fork
Watershed. Soil Science Society of America Journal 75:2271-2282.
doi:10.2136/sssaj2010.0440.
Stott, D.E., S.S. Andrews, M.A. Liebig, B.J. Wienhold, and D.L. Karlen.
2010. Evaluation of β-glucosidase activity as a soil quality indicator
for the Soil Management Assessment Framework (SMAF). Soil
Science Society of America Journal 74:107-119.
doi:10.2136/sssaj2009.0029.
Karlen, D.L., G.E. Varvel, J.M.F. Johnson, J.M. Baker, S.L. Osborne,
J.M. Novak, P.R. Adler, G.W. Roth, and S.J. Birrell. 2011. Monitoring
soil quality to assess the sustainability of harvesting corn stover.
Agronomy Journal 103:288. doi:10.2134/agronj2010.0160s.
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
Active Carbon Analysis
Active C Assay
Active carbon fraction:
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microbial biomass carbon
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particulate organic matter
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soil carbohydrates
Drives the soil food web; influence nutrient cycles and biological soil properties
Active carbon fractions indicate soil rresponse to different management systems
Compared to total organic C, active C may be more sensitive to management practices and more
closely related to soil productivity and biological soil properties such as respiration, microbial
biomass and aggregation.
See “Active C & SOC – Sanborn Field” pdf for comparison analyses of soils from long-term
management plots at Sanborn Field – Tables 2 &3
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO
SOIL QUALITY ASSESSMENT
‘Biologically-active soil C’ better describes
SQ than total SOM;
‘Conventional
Cultivation’
‘Grass Pasture’
‘Native Prairie’
Development of easy, quick,
in-field test, based on color
difference when reagents
mixed with soils, for use by
farmers is underway. Soils
collected from fields under
different management within
the watershed will be
assessed for effects on
biologically-active C and,
thus, Soil Quality.
Detected via oxidation of C by dilute
permanganate, thus reagent color
disappearance indicates higher C
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Active Carbon Analysis
Active C in soil extract can be
quantitatively measured in field
using a hand-held meter
(spectrophotometer)
Hach Company Instruments
Translating Missouri USDA-ARS Research and Technology into Practice
A training session provided by USDA-ARS-CSWQRU, 10-11 October 2012, Columbia, MO