NRCS Soils Data National Soil Information System NASIS

NRCS Soil Data Origins pre-date computers and models  data collection spans decades. Not designed or maintained with modeling in mind. Not perfect; need to have a procedure to handle errors and omissions. Must be adapted to meet model needs

NRCS Soil Databases Characterization Data 70+ years Support classification and Soil Taxonomy Support interpretations Point data, measured Horizons NASIS ~20 years, early computer tech Interpret char. data Provides interp. data for broad landuse decisions Mapunit based, not pt. Layers

NRCS Soil Databases Both NASIS and Soil Taxonomy are landuse independent. Characterization data may provide clues. Use Soil Taxonomy to fill or fix bad records.

NRCS Soil Databases NASIS reports a Representative Value (RV) and a range, hi and lo. Use the value that best reflects the landuse being modeled. The RV works better for empirical models like RUSLE than a process model like EPIC or APEX

Layer 1 Layer 2 Layer 3 Ap AB Bt1 Bt2 2Bt3 2Bt4

EFFECT OF NASIS RV CARBON Kenyon Apex Output Unadjusted C Adjusted C Corn Yield (bu) Carbon Trend Total N (lbs)8228 Total P (lbs) Sediment (tons)

Evesboro NASIS RV pH Layer (depth) NASIS pH Adjusted pH Layer m Layer m Layer m4.35.0

EFFECT OF NASIS RV pH Evesboro Apex Output Unadjusted pH Adjusted pH Corn Yield (bu)15147 Carbon Trend-4177 Total N (lbs)9940 Total P (lbs) Sediment (tons)

Evesboro NASIS RV Bulk Density Layer (depth) NASIS BD Adjusted BD Layer m1.39 Layer m1.43 Layer m

EFFECT OF NASIS RV Bulk Density Weikert Apex Output Unadjusted BD Adjusted BD Corn Yield (bu)8186 Carbon Trend91147 Total N (lbs)13597 Total P (lbs) Sediment (tons)2.52.1

Updates for modeling Established research grade position for modeling support for Soil Survey. Rapid C project. Collecting soil carbon data at NRI points. Error and omission checking. Begin collection of dynamic soil propeprties and data structure for dissemination.