Soil Quality Assessment: Past, Present and Future Douglas L. Karlen - - PowerPoint PPT Presentation

Soil Quality Assessment: Past, Present and Future

Douglas L. Karlen National Soil Tilth Laboratory

Presentation Outline Presentation Outline

What is soil quality assessment? What is soil quality assessment? What approaches can be used? What approaches can be used? Which approach should I use? Which approach should I use? Where do I see assessment going? Where do I see assessment going?

What is Soil Quality Assessment? What is Soil Quality Assessment?

The art and science of creating The art and science of creating decision tools for sustainable land decision tools for sustainable land management management The process of quantifying: The process of quantifying: “ “fitness for use fitness for use” ” or

• r

“ “capacity of a soil to function capacity of a soil to function” ”

Assessment Requirements Assessment Requirements

• Tools must be:

Tools must be:

• accurate

accurate

• simple to use

simple to use

• meaningful

meaningful

And And

• Provide s

Provide site ite-

• specific standards & guidelines

specific standards & guidelines for interpreting soil quality indicators for interpreting soil quality indicators

Inherent vs. Dynamic Soil Quality Inherent vs. Dynamic Soil Quality

• Inherent

Inherent -

• reflects basic soil forming factors

reflects basic soil forming factors

• climate, parent material, time,

climate, parent material, time,

• topography, and vegetation

topography, and vegetation

• (Reflected in Land Capability Classifications)

(Reflected in Land Capability Classifications)

• Dynamic

Dynamic -

• describes soil status or condition

describes soil status or condition

• reflects management decisions

reflects management decisions

• current or past land uses

current or past land uses

• (Reflects sustainability & conservation goals)

(Reflects sustainability & conservation goals)

Soil Quality Time

Soil B Soil A

Inherent Soil Quality Inherent Soil Quality

Dynamic Soil Quality Dynamic Soil Quality

Soil Quality Time

Aggrading Sustaining Degrading Baseline

Soil Organic Matter

1

6% 6%

Organic Matter Organic Matter

1

2% 2%

GA Ultisols IA Mollisols

What What Approaches Can Be Used? Approaches Can Be Used?

Indexes such as: AEPAT – AgroEcosystem Performance Assessment Tool SCI – Soil conditioning Index SMAF – Soil Management Assessment Framework

Scorecards Soil Pits Test Kit

Which Approach Should I Use? Which Approach Should I Use?

Scorecards Scorecards – – to build basic awareness of soils and to build basic awareness of soils and to document efforts to improve them to document efforts to improve them Soil Pits & Test kits Soil Pits & Test kits – – for education and building for education and building awareness of spatial & temporal variability awareness of spatial & temporal variability Indices Indices – –to identify most limiting factors, quantify to identify most limiting factors, quantify

• utcomes not effort, and to help set priorities
• utcomes not effort, and to help set priorities

for conservation investment for conservation investment

What Are Indices Assessing? What Are Indices Assessing?

Critical Soil Functions Critical Soil Functions – – or ability of soil to:

• r ability of soil to:
• Sustain biological productivity

Sustain biological productivity

• Regulate and partition soil water

Regulate and partition soil water

• Store and cycle nutrients

Store and cycle nutrients

• Function as a filter and buffer

Function as a filter and buffer

What Indices Are Available? What Indices Are Available?

• AEPAT

AEPAT – – AgroEcosystem Performance AgroEcosystem Performance Assessment Tool Assessment Tool

• SCI

SCI – – Soil Conditioning Index Soil Conditioning Index

• Cornell Soil Health Test

Cornell Soil Health Test

• SMAF

SMAF – – Soil Management Assessment Soil Management Assessment Framework Framework

AEPAT AEPAT

• Measured indicators assigned to various

Measured indicators assigned to various functions functions

• e.g. food/feed production & nutrient cycling

e.g. food/feed production & nutrient cycling

• Functions weighted by user

Functions weighted by user

• Function scores combined into index

Function scores combined into index

• Used to compare management practices

Used to compare management practices such as wheat such as wheat-

• fallow & continuous no

fallow & continuous no-

• till

till

Soil Conditioning Index (SCI) Soil Conditioning Index (SCI)

• NRCS adopted tool for predicting soil

NRCS adopted tool for predicting soil

• rganic matter trends
• rganic matter trends
• SCI = [OM*0.4]+[FO*0.4]+[ER*0.2]

SCI = [OM*0.4]+[FO*0.4]+[ER*0.2]

• Incorporated into RUSLE2 & is one

Incorporated into RUSLE2 & is one factor used by NRCS to evaluate EQIP factor used by NRCS to evaluate EQIP & CSP applications & CSP applications

Cornell Soil Health Test Cornell Soil Health Test

• Implemented in 2007 by Dr. Harold van Es

Implemented in 2007 by Dr. Harold van Es

• Uses biological, chemical, & physical indicators

Uses biological, chemical, & physical indicators

• Sensitive, relevant to critical functions,

Sensitive, relevant to critical functions, consistent & reproducible, easy to sample, and consistent & reproducible, easy to sample, and economical economical

• Purpose

Purpose – – education about soil health, targeting education about soil health, targeting management practices, monitoring for NRCS management practices, monitoring for NRCS programs, and to increase land value programs, and to increase land value

SMAF SMAF

• Developed first as Excel spreadsheet & used

Developed first as Excel spreadsheet & used to evaluate sustainability throughout U.S. to evaluate sustainability throughout U.S.

• Currently being made available on CD & web

Currently being made available on CD & web

• Uses multiple indicators

Uses multiple indicators – – goal is to have one goal is to have one

• r more representing biological, chemical,
• r more representing biological, chemical,

and physical properties & processes and physical properties & processes

SMAF SMAF –

– continued

continued

• Current scored indicators include:

Current scored indicators include:

• pH, P, EC, TOC, MBC, PMN,

pH, P, EC, TOC, MBC, PMN, Agg Agg Stability, Stability, Bulk density (D Bulk density (Db

b), AWC, SAR, qCO

), AWC, SAR, qCO2

2

• Scoring curve designs

Scoring curve designs

• More is better, more is worse, mid

More is better, more is worse, mid-

• point

point

• ptimum
• ptimum
• Overall index or individual indicators used to

Overall index or individual indicators used to evaluate management effects evaluate management effects

How Does SMAF Work? How Does SMAF Work?

Minimum Data Set Soil Function Indicator score Soil Function Soil Function Indicator Indicator Indicator

score score score

Index Value Management Goals

What What’ ’s the Future? s the Future?

Soil carbon content //

Monitoring Stover Removal Effects

Intensive Ag begins Management Changes Stover removal Offsetting Practices (no till, cover crops, diverse rotations, etc.) No Offsetting Practices

Time

?

Fields: blue dots sampling sites Buckeye Gauging Station CEAP Studies

Landscape Effects on Soil Quality Landscape Effects on Soil Quality

78 78 82 82 Hilltop Hilltop 89 89 94 94 Depression Depression 78 78 89 89 Toeslope Toeslope 77 77 88 88 Sideslope Sideslope ISA Study ISA Study Neppel Study Neppel Study Landscape Landscape Group Group SMAF SQI Values SMAF SQI Values

Summary & Conclusions Summary & Conclusions

• Soil quality assessment is here to stay

Soil quality assessment is here to stay

• Assessments provide information on overall

Assessments provide information on overall sustainability of agricultural systems sustainability of agricultural systems

• Meaningful measurements can be made and

Meaningful measurements can be made and interpreted interpreted

• Value added opportunities are available

Value added opportunities are available