National Commodity Crop Productivity Index (NCCPI)National Commodity Crop Productivity Index (NCCPI)

Robert DobosUSDA-NRCS National Soil Survey Center

Lincoln, Nebraska

Presented by Michael Robotham

NCCPI• Addresses problem / information need:

Consistently array soils nationwide on the basis of their inherent productivity for commodity crops

• Uses the soil and site data found in the soil survey database to assess relative soil productivity

• Based on established relationships between commodity crop yield and soil, site, climate, and landscape characteristics found the literature

Who needs the information• USDA Agencies: Relative value of land across geographic

regions in order to equitably provide funds for programs

• State and local governments: Relative productivity for assessment and taxation

• Risk Management Agency: Relative productivity of soils in order to assess the validity of insurance claims

• Private entities / land owners: Relative productivity of soils to evaluate hybrids and to make land use decisions

• Others: Seems someone new every day

Source of data

• SSURGO database – USDA-NRCS– Consistent data populated to national standards– Essentially the same data available on Web Soil Survey

• As the precision and accuracy of the data in the database is improved, the precision and accuracy of the model will improve

Data Used – Physical characteristics

• Root Zone Available Water Holding Capacity

• Bulk Density

• Saturated Hydraulic Conductivity

• Shrink-Swell

• Content of Rock Fragments

• Rooting Zone Depth

• Sand, Silt, and Clay Percentages

Data Used – Chemical Characteristics

• Cation Exchange Capacity

• pH

• Organic Matter Content

• Sodium Adsorption Ratio

• Gypsum Content

• Electrical Conductivity

Data Used– Landscape Features

• Slope Gradient and Shape

• Ponding Frequency, Duration, and Timing

• Flooding Frequency, Duration, and Timing

• Water Table Depth, Duration, and Timing

• Erosion

• Surface Stones

• Rock Outcrop

Data Used – Climate Factors• Mean Annual Precipitation

• Mean Annual Air Temperature

• Mean Annual Frost Free Days

• Major Land Resource Area

• Soil Temperature Regime

NCCPI Products• Main product is the array of the soils

• A yield can be derived from the index if a given level of management is assumed

• Results can be aggregated over map units and linked to SSURGO spatial data for mapping

• Since the relation of yield to properties is known, we can estimate the impact of a change (better or worse) in the modeled variables

• Useful for climate change, dynamic soil properties, and soil quality

A Small Case Study

Organic Matter Changes

Organic Matter Changes

In the Works and Future

• A stand alone soybeans module is being tested

• An irrigated version is also being tested

• Continue to refine current models

• Add new commodity crop, biomass, and forage models

• A new crop yield dataset is being developed and tested in cooperation with the Risk Management Agency

Additional information

• NCCPI v2.0 User Guide http://www.nrcs.usda.gov/wps/PA_NRCSConsumption/download?cid=nrcs142p2_050734&ext=pdf

• Robert “Bob” Dobos, Soil Scientist, National Soil Survey Center, Lincoln, NE– Bob.Dobos@lin.usda.gov– 402-437-4149

Thank You