Using Substance Flow Analysis to Estimate Nitrogen Input Changes in Animal Commodities with Continuous Cover Crops as Best Management Practices

For decades, people have been working on solutions to reduce nitrogen pollution in the Chesapeake Bay Watershed (CBW). Introducing perennial grasses and winter crops to maintain continuous cover in agricultural landscapes are two best management practices (BMP) that have effectively reduced nutrient inputs in the region. This work explores how implementing these BMPs reduces nitrogen input to commodities produced in the region. A substance flow analysis model was built to build life cycle inventories on nitrogen flows for four scenarios of commodity production in the CBW. The scenarios are divided into baseline, perennial grass or winter crop only, and perennial grass and winter crop. Six animal commodities were evaluated: beef, milk, pork, turkey, eggs, and chicken. In summary, the implementation of winter crop and a combination of winter crop and perennial grass reduces nitrogen input to four of the commodities assessed.