2006 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the University of Maryland-Eastern Shore. Additional details of research can be found in the report for the parent project 1902-13000-010-00D, "Optimizing Nutrient Management to Sustain Agricultural Ecosystems and Protect Water Quality." The objective of this cooperative research project is to establish a farm-based research site where the effects of land management on nutrient loss to surface water and develop Best Management Practices that minimize or decrease watershed export of nitrogen (N) and phosphorus (P). This project will also establish a research infrastructure between the 1890 University of Maryland-Eastern Shore (UMES), Princess Anne, MD, and USDA-ARS, Pasture Systems and Watershed Management Research Unit, University Park, PA, where undergraduate, graduate, and postgraduate students can gain first-hand experience in nutrient management and water quality research. The experimental site is a farm recently acquired by UMES, in partnership with the Manokin River Watershed Project with soils and topography representative of a large portion of the Delmarva Peninsula. Prior to acquisition by UMES, the farm was operated as a poultry farm with its cropped areas receiving large quantities of poultry manure. Consequently, nutrient concentrations, especially P, in the surface soil are excessive and pose a threat to water quality. This threat is exacerbated by the fact that fields are routinely drained by ditches to lower naturally high water tables that restrict field productivity. The ditches provide a rapid conduit for field nutrients to reach impaired surface waters. We will conduct field-scale studies to assess the fate of N and P applied to land as fertilizer and manure, describing chemical and physical interactions that control the transfer of N and P from soil to water and its subsequent transport in surface and subsurface flow from fields and subsequently in drainage ditches in Coastal Plain setting of the Delmarva Peninsula. We will identify key chemical and hydrologic factors controlling N and P loss, so that we can define management practices that minimize nutrient export to the Chesapeake Bay. We will also conduct research to evaluate in-ditch processes controlling when the ditches act as sources or sinks for N and P inputs, and which modify edge-of-field losses before entering the Chesapeake Bay, the ultimate point of impact of these losses. Traditional equipment will be used to collect flow and water samples (flumes, autosamplers, data loggers, piezometers) at selected field and ditch locations. From this research, we will develop land and nutrient management strategies, including models and decision support systems, which will provide viable and reliable solutions to decrease the impact of land-applied N and P on soil and water resources of the Peninsula. The research will enable best management practices to be targeted to critical areas for the most efficient and effective control of nutrient loss, thereby minimizing impacts on receiving waters.