National Strategy for Evaluating Soil Health Measurements. Wayne Honeycutt & Steven Shafer

Transcription

1 National Strategy for Evaluating Soil Health Measurements Wayne Honeycutt & Steven Shafer

2 Soil Health Measurements: Situation Analysis - Chemical & Physical Well-Established ( Tier 1 ) - Many Biological Measures, but Limited Evaluation ( Tier 2-3 ) - Several Promising Evaluation Programs Exist - Need Testing and Scaling-Up - None Adequately Relate Soil Health to Drivers of Adoption: Yield, Economics, Ecosystem Services - Variations in Soils, Climate, Management, Production System Influence Interpretation - Strategic, Nationally-Coordinated Approach Required

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13 Characterization of soil health measurement Tiers Tier 1: o o o o Tier 2: An effective indicator of soil health Defined regionally and by soil groupings across the nation Thresholds are known to indicate (at minimum) Poor, Adequate, and Good that are outcome based (yield, environmental goals, etc.) Specific management strategies can be suggested to improve soil functioning. o An effective indicator of soil health o Known to be related to improvements or degradation of soil o Potential ranges may be known in some regions but not nationally o Research is needed to establish thresholds to meet a relative standard of a healthy soil in various regions o There is some knowledge of management practices that can change measured values and the soil processes that affect observed measurement results. o Further development of a Tier 2 indicator may bring it into Tier 1. Tier 3: o o o An indicator that has potential to add significant information about soil health in specific locations or on large scales Specific relationships among measured values, soil processes, and effects of land management are not fully understood. Promising enough to warrant research on these relationships, as well as development of SOPs for production laboratory implementation and interpretation, in support of eventually developing them to meet Tier 1 criteria.

14 SHI s survey on Tier 1 Indicators Sent to 179 recipients - anyone who attended at least one: A Soil Renaissance Research working group meeting A Soil Renaissance Measurements working group meeting The first SHI annual meeting (July 2016 in Louisville) (Survey may have been forwarded to others) List of proposed Tier 1 indicators was derived from meeting report-outs and published in the SHI Action Plan. Respondents rated each proposed Tier 1 indicator 1 (not worth the effort and resources) to 10 (essential to measuring and understanding soil health)

15 Tier 1 Survey Results - 48 responses INDICATOR Min Max Median Mode Mean Organic carbon ph Water-stable aggregation Crop yield Soil texture Soil penetration resistance Cation Exchange Capacity Electrical conductivity Potassium Short-term carbon mineralization Nitrogen mineralization rate Visual rating of erosion Nitrogen % Base saturation Phosphorus Bulk density Micronutrients Nearly universal agreement Very strong agreement Clear consensus Moderate to weak consensus Ambivalence

16 Additional indicators nominated by respondents Some are already listed, some are Tier 2 or 3, some are metadata, some are unclear.. Active carbon Al % in acid soils (Ultisols, Oxisols) Available water capacity Below-ground insects Biology BMPs that affect soil health Color Crop and grain nutrient uptake Crop history Crop residue production Crop yield relative to an index Depth to saturation Effective rooting depth (300 psi) Expected baseline values Inorganic vs organic N pools Manure history Microbe, bacterial counts Microbial biomass Microbial diversity Microbiome Moisture holding capacity Nutrient stratification Nutrient supplying power, IEM Odor - living or dead? Organic matter Particulate organic C "Reactive" carbon (POXC etc.) Soil depth (A+B) Soil enzyme activities Soil microbial biomass C Soil moisture Soil protein Soil structure Surface residue mass or C content Tile drains Visible erosion Water infiltration rate Water percolation rate Water soluble nutrients Wet vs dry areas Worm numbers per unit volume Yield variability

17 Thank You! UNIFY RESTORE PROTECT

18 Conventional System Soil Improving System