Sunday, November 12, 2006

GIS NLEAP: A National User.

Christoph Gross, USDA-NRCS-Nat Wtr/Cl Ctr Rm 1-2150C, 5601 Sunnyside Ave, Beltsville, MD 20705-5420 and Jerrell Lemunyon, USDA NRCS, 2721 Ryan Place Dr., Fort Worth, TX 76110.


USDA Natural Resources Conservation Service (NRCS) has developed policy and conservation practice standards for implementing nutrient management planning as part of the over-all conservation plan. The nutrient management component of the plan involves the proper application rate, timing, form, and method of nutrients to landowner’s fields. Over 8 million acres of cropland and grazing land are planned with producers every year. Working with the landowner involves using land grant university crop nutrient recommendations based on soil and tissue testing for determining nutrient amounts and adjusting the proper form, timing, and method of application to fit the soil, climate, and cropping system in place. Nitrogen management can be based on risk analysis using the Nitrogen Losses and Environmental Assessment Program (NLEAP) model and the newly emerging Nitrogen Index under development. NLEAP can analyze risk of nitrogen loss and predict nitrogen use efficiency. While working with the landowner, the model can assess irrigation practices, timing of applications, form of nitrogen being applied, and the placement of the material on the field. Scenarios can be and planning adjusted to maximize nitrogen use efficiency while protecting natural resources against loss of nitrogen from the crop field by runoff, erosion, leaching, and atmospheric emissions. Data used for nitrogen management planning can then be stored as tabular data or as spatial data in a GIS database designed specifically for that landowner’s farm. It is envisioned that both the Nitrogen Index and NLEAP model can quantify both on-farm and watershed level benefits derived from the implementation of nutrient management plans.

Handout (.pdf format, 339.0 kb)