Model simulation and regional pollution reduction strategies

Abstract

The Chemical, Runoff, Erosion from Agricultural Management Systems (CREAMS) model was used to simulate the long‐term relative effects of different agricultural best management practices (BMP's) on nitrogen losses to surface and groundwater systems. Soils, geology, climate, and cultural practices of watersheds representing coastal plain (Wye watershed), Piedmont (field A), and Appalachian (field E) physiographic regions in the Chesapeake Bay basin were selected for simulation purposes. Different tillage practices (conventional till and no‐till) with and without erosion control structures, with and without a nutrient management plan, and with and without winter cover were selected for the purpose of this study. The results showed that a nutrient management plan (NMP) plays a major role in reducing surface and groundwater loadings of nitrogen. Although different practices were identified as being best or worst case scenarios with respect to surface and ground‐water loadings, respectively, closer examination and overall ranking revealed no‐till (NT) with NMP to be the optimum BMP studied in both the Piedmont and Appalachian regions. It was also found that winter cover results in significant reductions in N losses to surface and ground‐water systems in the coastal plain physiographic region. This study suggests that ranking and selecting the proper BMP should be based on its impact on both surface and groundwater quality rather than on a single resource. This is especially important considering the fact that both human and other living resources use both surface and groundwater for drinking or habitual environment.