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 or “ “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 s ite 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) �

Inherent Soil Quality Inherent Soil Quality Soil Quality Soil A Soil B Time

Dynamic Soil Quality Dynamic Soil Quality Baseline Aggrading Soil Quality Sustaining Degrading Time

Soil Organic Matter GA Ultisols IA Mollisols 1 1 6% 6% 0 Organic Matter 0 2% 2% Organic Matter

What Approaches Can Be Used? Approaches Can Be Used? What Soil Pits Scorecards Test Kit Indexes such as: AEPAT – AgroEcosystem Performance Assessment Tool SCI – Soil conditioning Index SMAF – Soil Management Assessment Framework

Which Approach Should I Use? Which Approach Should I Use? Scorecards – – to build basic awareness of soils and to build basic awareness of soils and Scorecards to document efforts to improve them to document efforts to improve them Soil Pits & Test kits – – for education and building for education and building Soil Pits & Test kits awareness of spatial & temporal variability awareness of spatial & temporal variability Indices – –to identify most limiting factors, quantify to identify most limiting factors, quantify Indices outcomes not effort, and to help set priorities outcomes not effort, and to help set priorities for conservation investment for conservation investment

What Are Indices Assessing? What Are Indices Assessing? Critical Soil Functions – – or ability of soil to: or ability of soil to: Critical Soil Functions � 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- -fallow & continuous no fallow & continuous no- -till till such as wheat

Soil Conditioning Index (SCI) Soil Conditioning Index (SCI) � NRCS adopted tool for predicting soil NRCS adopted tool for predicting soil � organic matter trends organic 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 � or more representing biological, chemical, or 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 b ), AWC, SAR, qCO 2 Bulk density (D b ), AWC, SAR, qCO 2 � Scoring curve designs Scoring curve designs � � More is better, more is worse, mid More is better, more is worse, mid- -point point � optimum optimum � 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? Management Goals Soil Function Soil Function Soil Function Indicator Indicator Indicator Indicator Minimum Data Set score score score score Index Value

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

Monitoring Stover Removal Effects Intensive Ag begins Stover removal // Soil carbon content Offsetting Practices (no till, cover crops, diverse rotations, etc.) ? Management Changes No Offsetting Practices Time

CEAP Studies Fields: blue dots sampling sites Buckeye Gauging Station

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

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 �