Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2005
Publication Date: July 17, 2005
Citation: Bosch, D.D., Strickland, T.C., Sullivan, D.G., Wauchope, R.D., Lowrance, R.R., Potter, T.L. 2005. Swat application for conservation effects assessment in the southeastern coastal plain. In: Proceedings of the ASAE. Paper No. 052040. Interpretive Summary: The Conservation Effects Assessment Program (CEAP) was implemented by the USDA to better quantify the effects of its conservation programs. This information will allow policy-makers and program managers to implement and modify existing programs and design new programs to more effectively and efficiently meet program goals. A computer simulation model, SWAT, was used to examine the impacts of alternate land management practices on water quantity and quality within a Coastal Plain Watershed. The model indicated that a greater benefit can be expected for some water quality indicators than for others when these practices are implemented. The simulations also indicated that water quality can be expected to improve linearly as more acreage is converted into conservation systems. However, there does appear to be concern for increased chemical losses to groundwater. This information will help planners select where conservation programs are implemented throughout the Coastal Plain and the degree of land management necessary to meet defined water quality goals.
Technical Abstract: The USDA has implemented the Conservation Effects Assessment Program (CEAP) to better quantify the effects of its conservation programs. One of the methods being used is the utilization of watershed scale computer simulation models. The models will be used to predict the long-term environmental impacts of USDA conservation programs. The Soil Water Assessment Tool (SWAT) was used to examine the impacts of alternate land management practices on water quantity and quality within a Coastal Plain Watershed. Runoff, sediment, and pesticide loadings were examined. SWAT simulations indicate a linear decrease in sediment and pesticide yields will be observed if conservation tillage is implemented on the cotton acreage within this watershed. For sediment, a 20% reduction in loss can be obtained through implementation of conservation tillage on 15% of the watershed area. SWAT simulations indicated that a 45% reduction in the simulated pesticides can be expected when the conservation practices are implemented on the same acreage. However, the model simulated an increase in water yields from the watershed when these practices were implemented, likely due to increases in infiltration in the uplands. This increase in infiltration and subsequently streamflow could result in greater losses of soluble chemicals, particularly nitrate.