Modeling Best Management Practices on Representative Farms in Southeastern Pennsylvania Using the Integrated Farm System Model

Open Access
McLean, Andrew Duart
Graduate Program:
Agricultural and Biological Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
December 13, 2011
Committee Members:
  • James Michael Hamlett, Thesis Advisor
  • Tamie L Veith, Thesis Advisor
  • Clarence Alan Rotz, Thesis Advisor
  • James Samuel Shortle, Thesis Advisor
  • BMP
  • model
  • IFSM
  • Amish
  • nutrient
  • profitability
According to the U.S. EPA, agricultural runoff is the largest source of water quality degradation in the Chesapeake Bay, accounting for 44 percent of all nutrient pollution and 65 percent of sediment pollution that enters the Bay (USEPA, 2010b). Pennsylvania produces the second most agricultural pollution of the six states within the Bay Basin. To combat agricultural pollution, farmers and conservation agencies around the country are turning to best management practices (BMPs). There are many types of agricultural BMPs, but their effectiveness differs from farm to farm depending on where they are applied, how they are applied, and how they are impacted by weather. The goal of this research was to determine the effects of BMP implementation on environmental losses and farm profitability, as applied to typical farms in the Lancaster, Lebanon, and Dauphin County region of Pennsylvania. Analysis and evaluation of BMPs was conducted by modeling farms and BMPs using the Integrated Farm System Model (IFSM). Three baseline farms were developed to simulate typical farms in this region; a crop farm, an English dairy farm, and a Plain Sect Amish dairy farm. BMP scenarios applied to the baseline representation of those farms were evaluated based on reduction of sediment and nutrient losses and impact on farm profitability. The effects of BMPs were different for each farm. Environmental losses on all farms were reduced by employing strip cropping, nutrient management, reduced tillage, and cover cropping. Planting and harvesting of a winter cover crop reduced environmental losses over baseline conditions for the English dairy and crop farms, while increasing farm profit. Profit increased 122% over the baseline condition when the harvested cover crop practice was combined with nutrient management on the crop farm. Cover cropping without harvest of winter crops was effective at reducing nutrient and sediment losses for the Amish farm, while additional reductions in phosphorus and sediment losses of 71% and 91%, respectively, were observed when cover cropping was combined with no-till planting. The English dairy baseline had fairly low environmental losses but implementation of improved nutrient management achieved an 8% reduction in nitrogen leaching while increasing profit by 17%. For all farms, strip cropping provided a substantial decrease in losses of most nutrients and sediment and had a negligible impact on farm profitability. Using IFSM to model multiple farm categories, each with multiple BMPs, produced valuable information for regional officials who make BMP recommendations for farms in the focus area. Comparing profitability and environmental effectiveness of BMPs across multiple farm types exposes relationships between BMP suitability and farm type that should prove valuable to increasing BMP adoption, educating farmers and the public, and improving water quality.