2007 Annual Report 1a.Objectives (from AD-416) Principal focus of the CEAP effort is to produce an assessment of environmental benefits of conservation practices to support policy decision and program implementation. 1b.Approach (from AD-416) Utilize ARS historical watershed databases to validate the SWAT model and then utilize this model to determine the impact of conservation practices on water quality, soil quality, air quality, and wildlife habitat. 3.Progress Report This report documents research conducted under a Reimbursable Agreement whereby the Natural Resource Conservation Service funded ARS for research in support of the Conservation Effects Assessment Project (CEAP). Additional details can be found in the report for the in-house associated project CRIS 1902-13000-010-00D, "Optimizing Nutrient Management to Sustain Agricultural Ecosystems and Protect Water Quality," and the research directly addresses Objective 1: Quantifying P, N, and C Cycling, Project 1.3: Quantify P, N, and C cycling at farm and watershed scales. This research also addresses replacement in-house project CRIS 1902-13000-011-00D, "Integrated Management of Land and Water Resources for Environmental and Economic Sustainability in the Northeast U.S." and contributes to Subobjective 5.1: “Develop tools and strategies through which field, watershed, and landscape scale environmental impact assessments are considered in the context of farm level N and P management decisions.” The general objective of this effort is to assess the environmental benefits of conservation practices in support of policy decision and program implementation and includes development, implementation, and evaluation of Best Management Practices (BMPs) for reducing P loss from agriculture within the P-restricted Cannonsville Reservoir Basin in New York. Coordinated in-field research is being conducted in the Cannonsville Watershed, and to date we have conducted sampling and experimentation at plot, field, and farm scales to characterize surface runoff contributing areas. Progress is being made toward modifying SWAT to reflect variable source area hydrology and better target geographical sites of nutrient loss. Modeling, using the Integrated Farming Systems Model (IFSM), showed that precision feeding of dairy cows to recommended dietary P recommendations and making maximum utilization of on-farm produced forages results in overall balance between P imports and exports at the farm scale.