|Hively, Wells - Dean|
Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2008
Publication Date: 11/1/2008
Publication URL: http://handle.nal.usda.gov/10113/22915
Citation: McCarty, G.W., McConnell, L.L., Sadeghi, A.M., Hapeman, C.J., Graff, C., Hively, W.D., Lang, M.W., Fisher, T.R., Jordan, T., Rice, C., Whitall, D., Lynn, A., Keppler, J., Fogel, M.L. 2008. Overview of the Choptank River watershed conservation effectiveness assessment project. Journal of Soil and Water Conservation. 63:461-474. Interpretive Summary: The Choptank River watershed Conservation Effectiveness Assessment Project (CEAP) has emerged as an important component in the overall effort to improve water quality in the Chesapeake Bay. Limited information is currently available on the effectiveness of many important conservation practices on a watershed scale, especially in the Mid-Atlantic region. In comparison with wastewater treatment plant improvements, agricultural best management practices (BMPs) have been identified as some of the most cost-effective measures for water quality. Our current water quality monitoring efforts for nutrients, suspended sediments, and pesticides have centered on 15 small, agricultural sub-basins with periodic collections from the lower estuary. Within the project remote sensing tools are being developed to assess the effectiveness of cover crops at sequestering nutrients. Innovative research tools are being developed to measure denitrication at landscape scales and assess effectiveness of riparian buffers. Additionally, satellite-based radar tools are being developed for forested wetland detection and characterization. Initial calibration and validation of the USDA water quality models has also been completed so that watershed scale assessments of BMPs effectiveness can be performed. These efforts should lead to improved management tools for agricultural ecosystems resulting in reduced nutrient loading of streams and improved Chesapeake Bay health.
Technical Abstract: The Choptank River is a benchmark watershed in the Conservation Effectiveness Assessment Project. It is an estuary and tributary of the Chesapeake Bay. Land use in the watershed (2057 square km) is classified as 52% agriculture, 26% forested, and 5% developed. Agricultural production is centered on the poultry industry with large-scale corn, soybean, and small grains production. Historical water quality datasets are available for several stations within the watershed, and a number of sites within the estuary are part of larger, on-going Chesapeake Bay water quality monitoring networks. A systematic monitoring program in place since the mid-1980’s has shown that dissolved oxygen levels in the estuary are decreasing due to nutrient and sediment pollution. In this project, current water quality monitoring efforts for nutrients, suspended sediments, and pesticides have centered on 15 small, agricultural sub-basins with periodic collections from the lower estuary. Remote sensing tools combined with ground-level measurements are being used to assess the effectiveness of cover crops at sequestering nutrients. Nutrient isotope signatures and accumulation of excess dinitrogen gas in groundwater are being utilized to examine the process of denitrification in riparian areas and stream buffers. Satellite-based radar tools are being developed for forested wetland detection and characterization. Initial calibration and validation of the Annualized Agricultural Non-Point Source and Soil and Water Assessment Tool models has been completed. Preliminary model scenarios indicate extensive implantation of cover crops and other conservation practices will be required before observable improvements in water quality will be achieved.