Development of Soil Quality Assessment Tools in the US

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Development of Soil Quality Assessment Tools in
the US

• Susan Andrews
• Soil Quality Tech. Dev. Team
• USDA-NRCS

NRCS
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Soil Quality Tool Development Approach
issue driven
Sustainable Decision- Making
research based
user input
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Overview

• Concepts and Issues
• Focus Group Results
• Research and Development

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Soil Quality Definitions
capacity of the soil to function -
Karlen et al. 1997

• fitness for use
• - Larson Pierce, 1991

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What is soil function?

• What a soil does
• A.K.A.
• Ecosystem services

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Soil Functions

• Maintaining biodiversity productivity

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Soil Functions

• Regulating and partitioning water and solute flow

Runoff
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Soil Functions

• Filtering buffering

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Soil Functions

• Storing and Cycling Nutrients

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Soil Functions

• Physical Stability and Support

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Inherent vs Dynamic Soil Quality

• reflects natural characteristics
• based on soil forming factors
• climate, parent material, topography, and
  vegetation, all acting over time Jenny, 1941
• describes status or condition of soil
• result of land use or management practice

• INHERENT
• DYNAMIC

- after Pierce and Larson, 1993
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SO WHAT?
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US Farmers Definitions
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US Farmers Definitions continued
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Soil Quality A Component of Sustainability
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What US Farmers Wanted

• research showing the relationship between soil
  quality and economics

Is there real economic value you can place on a
certain level of measurable of soil quality?

SVJ farmer
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Cost of SQ loss via Erosion

• Degrades organic matter levels and other fines
  first

Off-site values
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Dissatisfaction with Available Tools
It is astonishing to me that they're still
only giving me a one page soil test.
You need a more sophisticated tool than that.
SJV farmer  
  I might as well be speaking to crop
advisors in Russian, about worrying about carbon
levels or C to N ratios.
SV farmer
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Soil Quality Assessment
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What US Farmers Wanted

• predictions of management practice effects on
  soil quality
• If I switched to no-till, what outcomes can
  I expect?
  IL-IA farmer

• ability to make soil quality comparisons over
  time, including changes in carbon
• site-specific interpretations for indicators

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MAP 40. Soil Quality Degradation Indicator for
Cropland
Predictive Tools
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Soil Conditioning Index (SCISoil
DisturbancePlant ProductionErosion)
Carbon (lbs)
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Practice Based Indices
Do you use conservation tillage? Do you rotate
crops? Do you use cover crops? Do you use
rotational grazing?
SQ Score
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Comparative Tools
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Soil Health Scorecards

• Qualitative
• Self Assessment Tool
• Developed by Farmers for Farmers
• Uses Farmer-Based Descriptive Terms
• Promotes Awareness of Soil Quality
• Based on Wisconsin Health Card
  
• - Romig et al., 1995

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Soil Quality Card Design Guide

• How to develop health cards with local farmers
• Focus group and consensus building techniques
• Interpretation limited

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Semi-Quantitative Kits
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Soil Quality Test kit Guide

• Test procedures
• General interpretations
• Spreadsheets available
• Who performs?
• Lacks C assay

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Site Specific Tools
Inherent SQ
Soil Function
Soil A Soil B
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Site-Specific Interpretation
GA Ultisols IA Mollisols
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Soil Management Assessment Framework
- Andrews et al., 2002
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Step 1 Indicator Selection
Management Goals

• In addition, selection depends on Crop
  Practice Inherent Soil Region Scale

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2. Interpretation
Productivity
Ecosystem Function
Nitrogen Added (kg/ha)
- after DeFries et al., 2002
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Step 3 Integration
Low score for bulk density suggests impaired
rooting and aeration due to aeration Consider
controlled traffic, reduce tillage, sub-soiling,
no traffic when soils are wet
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What do farmers think?
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Comparison of SQ Indices with Farmer Perceptions

• Biologically Integrated Farming Systems Project
• 14 participating farms
• side-by-side fields with organic amendment
  alternatives

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Index Results Over Time
BIFS Farm 2
Index Value
Nov 95 Nov 96 May 97
Nov 97 May 98
Sampling Date
denotes significance at 0.005
-Andrews et al., 2002
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Survey Question 1
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Farm-Specific Indexhanded out after question 1
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Survey Response 2
How well did the index reflect your perception of
soil quality?
N 12 Mean 8 Std. Dev. 1 Range min. 6
max. 10
-Andrews et al, 2003
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Farmers Responses

• Most felt the calculated index scores reflected
  their perceptions
• ... the overall soil quality score indicates
  what I was thinking
• it came out exactly the way I scored it
• All used yield as their metric of soil quality

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Summary

• US farmers wanted comprehensive management tools
• Research needed
• Tie SQ and economics,
• Qualitative indicators and management
  prescriptions
• Develop in-field carbon measures
• Interpretation of indicators must be
  site-specific
• SQ assessment tools can meet this need
• Continued development is needed

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Before researchers become researchers they
should become philosophers. They should consider
what the human goal is, what it is that humanity
should create. Masanobu
Fukuoka