1a. Objectives (from AD-416):
Principal focus of the CEAP effort is to produce a national assessment of environmental benefits of USDA conservation programs 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:
The national cropland component of CEAP was undertaken to determine the environmental impacts of USDA conservation programs on cultivated agriculture across the continental U.S. The CEAP modeling system is now being used to aid in developing USDA conservation policy. The first phase of cropland CEAP at the 8-digit scale for all major river basins with cultivated agriculture, including the Chesapeake Bay, Southeast, Upper Mississippi, Lower Mississippi, Ohio/Tennessee, Texas Gulf, Missouri, Arkansas/Red/White, and Columbia basins, were completed. All models were validated, and scenarios for tillage, fertilizer/manure management, and structural practices were analyzed and reports written. The Chesapeake Bay model was rerun with updated climate data, land use, and management. Work was initiated to develop climate change scenarios for the cropland assessment. Regionalized output from global circulation models was assembled for input to SWAT and APEX, and model simulations and analysis will be performed next year. Considerable effort was directed toward Phase II of cropland CEAP, which includes downscaling from 8-digit subbasins (approximately 3,000 km2) to 12-digit subbasins (approximately 100 km2). When Phase II is completed it will provide a tool for determining the impacts of existing and proposed USDA conservation policy at the national scale and also for state and local planning.