Using NRI Simulation Modeling to Identify Priority Cropland Acres for Conservation Program Implementation

The National Resources Inventory (NRI) provided the analytical framework for a simulation modeling approach to identify cropland acres with the greatest potential for soil loss, nutrient loss, and soil quality degradation. The physical process model EPIC (Erosion-Productivity Impact Calculator) was used to estimate surface water runoff, percolation, wind erosion, sediment loss, nutrient loss, and changes in soil organic carbon for each NRI cropland sample point included. More than 750,000 EPIC model runs were conducted. Model results were estimated for 15 crops representing approximately 298 million acres, or 79 percent, of U.S. cropland, exclusive of acres enrolled in the Conservation Reserve Program.

The last map shows priority cropland acres for conservation program implementation based on estimates illustrated in the other eight maps, which show potential losses of soils and nutrients from farm fields and the potential for soil quality degradation. Priority acres—those most in need of conservation treatment—are critical for one or more of the eight on-site environmental outcomes. For each outcome, critical acres were identified as those with the highest loss estimates (or lowest soil quality rating) in the country, generally representing those in the top 15 percent nationally.

For more details, see "Model Simulation of Soil Loss, Nutrient Loss, and Change in Soil Organic Carbon Associated with Crop Production" by Potter, Andrews, Atwood, Kellogg, Lemunyon, Norfleet, and Oman. June 2006. U.S. Department of Agriculture, Natural Resources Conservation Service.

Courtesy of Natural Resources Conservation Service.