Drainage ditches are an integral component of many agroecosystems, functioning to improve field drainage for crop production but also serving as key pathways of phosphorus and nitrogen export. The nutrients phosphorus and nitrogen are causes of eutrophication of the Chesapeake Bay and other water bodies. Eutrophication is a common water quality impairment that causes low oxygen levels in waters. In ditch-drained regions, efforts to address agricultural losses of nutrients have focused primarily on field management and have not accounted for the modifying effect of ditches on water quality. Improved ditch management could be an effective component of regional nutrient management planning and policy. This project will result in the development of management recommendations that can be applied to ditch-drained agroecosystems and are of immediate relevance to ongoing efforts to reduce nutrient inputs from the Delmarva Peninsula to the Chesapeake Bay.

Funding for this project comes from the USDA National Integrated Water Quality Program, the USDA Capacity Building Grants Program, and the USDA Agricultural Research Service. Stakeholder involvement includes the participation of four local farmers.

Arthur Allen, University of Maryland Eastern Shore, Princess Anne, MD

Brian Needelman and Frank Coale, University of Maryland, College Park, MD

Peter Kleinman, Peter Vadas, John Schmidt, Curtis Dell, Andrew Sharpley, and Ray Bryant, USDA Agricultural Research Service, Pasture Systems and Watershed Management Research Unit, University Park, PA

John McCoy, Maryland Department of Natural Resources, Annapolis, MD

We are in the early stages of this long-term project. Our work to this point has been focused at the University of Maryland Eastern Shore Research Farm in Princess Anne, MD, a farm with a 30-year history of poultry manure application. We have found that the materials found in these drainage ditches are soils, rather than sediments as is commonly stated. Large quantities of phosphorus have been measured flowing out of shallow drainage ditches. This phosphorus seems to be coming from the shallow ground water or from the ditches themselves, not from surface runoff from the fields. We have observed high concentrations of phosphorus in the ground water, indicating that management may need to focus on what's below the surface.

The project is broad and includes watershed-scale, on-farm, and greenhouse studies. We are studying a range of processes such as nitrogen fertility, nitrous oxide emissions, sulfide formation, organic matter functions, heavy metal toxicity and transport, and the ability of industrial by-products to soak up excess phosphorus. We also run an annual summer high school program designed to prepare students from under-represented groups to enter the workforce and to get communities involved via their young scholars.