Soil Quality and Soil Health: Are they different? and Do they matter?

1. Soil Quality and Soil Health: Are they different? and Do they matter? Susan Andrews, National Leader Soil Quality and Ecosystems National Soil Survey Center August 9, 2012

2. Soil Quality Definitions “capacity of the soil to function” - Karlen et al. 1997 “fitness for use” - Larson & Pierce, 1991

3. Soil Functions Recognized by USDA-NRCS • Maintaining biodiversity & productivity • Partitioning water and solute flow • Filtering and buffering • Cycling and storing nutrients [and energy] • Structural support and stability - after Seybold et al., 1997

4. INHERENT SOIL QUALITY • DYNAMIC SOIL QUALITY - after Pierce and Larson, 1993 Types of Soil Quality • reflects natural characteristics • based on soil forming factors • climate, parent material, topography, and biota, all acting over time – Jenny, 1941 • describes status or condition of soil • result of land use or management practice

5. Similar Terms • Genetic v. Kinetic -Richter, 1987 • State v. Behavioral • Koolen, 1987; Carter et al., 1997 • Genoform v. Phenoform • Droogers and Bouma, 1997

6. Dynamic SQ Dynamic SQ with respect to Inherent capability 50% 85% Both Types of SQ are Important Inherent SQ Soil Function Soil A Soil B - after Andrews et al., 2004

7. Soil Health v. Soil Quality • Soil health is used as a synonym for soil quality - Doran and Parkin, 1996 • Minor exceptions: • Soil health includes only dynamic quality • Sometimes greater emphasis on biology A soil may have poor inherent soil quality but still have good soil health. • Gregorichand Carter, 1997

8. SQ and SH Use in NRCS It’s not enough for planners to memorize practices, there must be an understanding of principles Assessment: Conservation Delivery Streamlining Soil Survey: Dynamic Soil Properties Inventory Policy and Programs: EQIP; CSP Chief’s Initiative: Soil Health Management Systems

9. Why is soil quality/health important? Foundation resource Fundamental to sustainability Values and Value

10. Soils are the Foundation Resource With loss of soil function air and water quality degrade

11. Agricultural Sustainability Environmental Quality Economic Viability Social Acceptability Soil Quality as a Component of Sustainability Environmental Quality Air Quality Water Quality Soil Quality -after Andrews et al., 1998; 2002

12. Soil Quality and Sustainability • Considered an indicator of sustainable land management – Doran and Zeiss, 2000 • Change in SQ with time is the primary indicator of sustainable land management –Karlen et al., 1997

13. Value-Laden Term • Human values (and social mores) can’t be ignored • Values are represented in management goal -oriented definition of soil quality • Values may be monetary or non-monetary • Farmers define SQ in economic terms • Economists use multiple ways to assign value • Building quality is linked to several f.b. programs

14. Principal Threats to Soil Quality: • Erosion • Organic matter decline • Salinization • Soil biodiversity loss • Compaction • Landslides • Contamination • Sealing - EUC: Thematic Strategy for Soil Protection, 2008 Why do some soils resist degradation better than others?

15. Components of Functional Stability • Soil Resilience The ability of a soil to recover its previous level of function after a disturbance • Soil Resistance • The ability of a soil to resist change in function throughout a disturbance - Pimm, 1984; Seybold et al., 1999; Andrews, 2003

16. Soil with low resistance and high resilience Soil with low resistance and low resilience Differences in Resistance and Resilience Soil with high resistance Soil Function Time (years) Compaction Disturbance -Seybold et al., 1999

17. Some Factors Affecting Resistance and Resilience • Disturbance • Diversity & Complexity • Water, Nutrients & Energy • Soil Texture • Soil Depth • Soil Horizon Sequence (Organic Matter) These factors are difficult to manage! These factors can be managed! -after Carter et al., 2003

18. / Function -Neher, 1999, Carter et al., 2003, Andrews, 2003 Intermediate Disturbance Hypothesis Diversity Disturbance frequency or intensity - Connell, 1978

19. / Function -Neher, 1999, Carter et al., 2003, Andrews, 2003 Intermediate Disturbance Hypothesis Diversity Disturbance frequency or intensity - Connell, 1978

20. / Function -Neher, 1999, Carter et al., 2003, Andrews, 2003 Intermediate Disturbance Hypothesis There are many paths to the sustainable land management Diversity Disturbance frequency or intensity - Connell, 1978

21. Examples for agricultural systems include: • Heavy traffic load • Tillage • Fertilizers • Pesticides • Monoculture • Pollutants • Saline irrigation water • Grazing pressure • Weeds • Climate What is a disturbance? A natural or human induced stress

22. Rotational Grazing is intermediate disturbance Reeder (2002) found the highest levels of SOM under intermediately grazed grasslands

23. Manage for Reduced Disturbance • Types of Disturbance • Physical • Biological • Chemical • Management Strategies • Minimize tillage • Increase diversity • Precision application -after Carter et al., 2003

24. Conservation Tillage

25. Soil Function Time Soil Resilience Decreasing with Time (with frequentdisturbance) Disturbance Disturbance -Seybold et al., 1999

26. Disturbance Soil Function Time Effect of Improved Management Reduced Disturbance -Seybold et al., 1999

27. Management Examples • Cover crops, varieties • Intercrop, trap crops • Use of Rotations • Organic amendments • Limit-specific crops Manage for Increased Diversity (biological disturbance) • Some Types of Diversity & Complexity • Species & Genetic • Habitat • Temporal • Food Web ‘Health’ • Targeted solutions -after Carter et al., 2003

28. Cover Crops (PMC SH Study)

29. The Roller Crimper

30. Tools to Apply SQ Principles to meet NRCS needs • Simple tools for conservation planning (CDSI) • DSP database and interpretations • Identify and quantify soil function • Agronomics, forestry, range, economics • Soil Health Management System Initiative

31. Tools for á la carte Assessment Visual assessment to determine likely problems Simple decision tool to aide choice of tests Needs to be interactive to suggest appropriate tests by region and management system

32. 103 103 103 250 103 Inventory of Dynamic Soil Properties (DSP) • Database of affects of management on function • Focus on reversibility of function loss(Arnold et al.,1990) • Different effects for various soils and climates • Useful to suggest mgt. alternatives and programs Land degradation Productivity Land use impacts

33. SH Management Systems Must adhere to principles of IDH by allowing many paths to build soil health Can encourage innovation to address site-specific issues and management goals Need a simple tool to mix and match practices Tool can then point user to management templates or job aids, specific to building SH

34. Tool to Build a Custom SHMS • Example: • Choose a minimum of five practices, at least one from each • disturbance category • Could weight practices by effectiveness and require a • minimum score (similar to CMT or SWET) Practices that Alleviate Physical, Chemical and Biological Disturbance

35. Summary • Soil Health and Quality are synonymous • Resistance and resilience dictate the soil’s function response to disturbance • Intermediate levels of disturbance, regardless of method, relate to higher function • For greatest sustainability, manage for: • Reduced physical, chemical & biological disturbance • Increases overall function and diversity • Increases system stability • Optimizes cycling of nutrients, water and energy

36. Questions? Contact: Susan Andrews susan.andrews@lin.usda.gov

37. “To skin and exhaust the land will result in undermining the days of our children.” Theodore Roosevelt