Understanding the Dynamics of Nutrient Management and Runoff from Plant Farms in the Potomac Watershed: Take Example of Nitrogen Management in Corn Planting of Frederick

Abstract

In this paper, we focus on nitrogen load from corn planting in Frederick, in order to explore a generalized system dynamics structure and policy indications for nutrient pollution from agricultural planting in Potomac watershed. The structure contains two sections: commodity production structure and nitrogen application structure, which separately focus on two core variables as planting acreage and nitrogen application. We find leverage points from structure analysis, simulation results and literature. Nitrogen application control is most efficient method for nitrogen load reduction while soil quality preservation is most significant and has long-term effect for the whole system. Manure application shows more problems than fertilizer application while manure management and transportation are seen as important for manure application control. We further analyzed related best management practices and compared implementation feasibility for each policy. The system dynamics model has reproduced the reference mode, passed sensitivity test and robustness test. The test of soybean planting in commodity production structure indicates the structure can be generalized to similar agricultural products.