Agricultural best management practices and water quality in the Bush River watershed, Virginia

This project was developed as part of the implementation phase of the PL 92-500 Section 208 Program for control of nonpoint pollution from agricultural sources. The project objective was to determine the effect of Best Management Practices on sediment and nutrient yields in agricultural watersheds.

The research consisted of field monitoring at two small watershed sites in the Bush River basin, near Farmville, Virginia. One watershed used Best Management Practices (BMP Watershed) consisting of contour strip cropping in combination with crop rotation and sod waterways. The second watershed, with conventional management ( CONV Watershed), was approximately half agricultural and half forested. Concurrent with the small watershed monitoring study, a weekly sampling program was maintained to evaluate the ambient water quality on the main tributary system of the Bush River.

The results of the study include the first field-based quantification of sediment yield and delivery ratios in this area. Although the results of this study are not conclusive, the agricultural watershed with recommended Best Management Practices tended to produce reduced levels of gross erosion, runoff, and sediment and nutrient yields. Sediment delivery ratios were compared with several alternative estimation techniques. Particle size distributions, nutrient enrichment ratios and sediment delivery ratios estimated in this study may be useful in computing nonpoint pollution effects of agricultural land use in the Southeastern Piedmont of the United States. The ambient data developed in this study may be useful in the future to estimate the effect of a planned PL-566 Conservation Plan that is being implemented on the Bush River watershed.