2007 Annual Report 1a.Objectives (from AD-416) Establish benchmark assessment of NRCS/FSA Conservation Programs for application of REMM and SWAT models to provide watershed-scale assessment of conservation practices in the Choptank River Watershed. Establish contacts and carry out regular information sharing opportunities with poultry producer groups within the Choptank River Watershed. 1b.Approach (from AD-416) This project combines the use of historical water quality databases that exist for the Choptank River Watershed with current monitoring within specific sub-watersheds with varying percentages of CRP and CREP installations. This data will be used to build a functioning watershed model to evaluate the effectiveness of conservation practices such as CRP and CREP. A set of 15 subwatersheds (a series of 2nd and 3rd order streams) will be monitored under base flow and storm conditions for nutrients and other water quality indicators. Partnerships will be sought with producer groups in order to communicate with producers in the watershed to obtain information on current nutrient management practices. GIS maps with high resolution datasets for land use, soil types, and other related water quality measurable endpoints will be used to construct the model. Preliminary results of the assessment will be made available to the producers and other customer groups throughout the two-year period as datasets are developed and interpreted using venues that are appropriate and convenient for the customers. 3.Progress Report This report documents research conducted under an Interagency Reimbursable Agreement between the ARS and USDA Natural Resource Conservation Service. Additional details of research can be found in the report for the parent project 1265-12130-002-00D entitled, "Assessing climate, soil and landscape processes affecting agricultural ecosystems” and SCA 1265-12130-002-05S "Evaluation of conservation practice effectiveness in water quality protection in the choptank river watershed." The NRCS Choptank Special Emphasis CEAP Watershed project has been coordinated with the National Cross Location Project for ARS Benchmark watersheds. The Choptank watershed complements this national network of watersheds in that it is the only tidal estuary under study within the CEAP effort. Within the Choptank watershed project, we are developing efficient monitoring technologies that can be used operationally for assessment of the parameters within the cover crop program. Such information can then be used by program managers to optimize implementation of cover crops in the Chesapeake Bay region. It can also be used by better parameterize water quality models. An important objective of the Choptank watershed project is water quality modeling to assess the effectiveness of Best Management Practices (BMPs) for improved quality of water draining from the watershed into the Chesapeake Bay. Under this project, GIS data layers have been developed for landuse information, derived from aerial photos, and current BMP implementation, obtained from county conservation offices. These data layers provide input to the water quality models. This effort has resulted in successful calibration of AnnAGNPS using historic data from the German Branch sub-watershed located in the Tuckahoe subbasin within the Choptank watershed. Data being collected on German Branch as well as 14 other sub-watersheds within the Tuckahoe sub-basin under this project will provide data for validating simulation runs of the model testing different scenarios of BMP implementation for improved water quality. Initial simulation runs for BMP implementation have performed out using the German Branch landuse/BMP data layers. Assessment of current impacts of agricultural BMPs on water quality were performed by monitoring stream water exiting from 15 subwatersheds within the Tuckahoe Creek sub-basin. These water samples were been analyzed for nutrient and pesticide content with data compiled. Select storm flow events have also been sampled and analyzed for water quality. The depth of water in each stream have been continuously monitored and data logged and development of rating curves for each stream is in progress based on water flux measurements at different stages of stream. A series of significant storm events during the year have provided good opportunity to establish rating curves by use of an Acoustic Stream Channel Profiler. This effort will continue into FY 2008. These data collection efforts will provide validation data for the AnnAGNPS and SWAT water quality models.