The effects of different agricultural land-management practices on sediment, nutrients, and selected pesticides in surface water, and on nutrients and pesticides in ground water were studied in four small basins in the Piedmont of North Carolina. The basins included two adjacent basins in row-crop fields, a mixed land-use basin, and a forested basin. One of the row-crop fields was farmed using conservation land-management practices, including strip cropping, contour plowing, field borders, and grassed waterways. The other field was farmed using standard land- management practices, including continuous cropping, straight-row plowing, and ungrassed waterways. The sediment yield for the standard land-management basin was 2.3 times that for the conservation land-management basin, 14.1 times that for the mixed land-use basin, and 19.5 times that for the forested basin. Nutrient concentrations in surface water from the row-crop and mixed land-use basins were higher than those in surface water for the forested basin. Nutrient concentrations in soil water and ground water beneath the row-crop basins were lower than those in surface- water runoff for these basins. The lowest nutrient concentrations measured in the row-crop basins generally were in soil-water samples collected just below the root zone (3-foot depth) and in ground water. No significant differences in pesticide concentrations were identified between the surface-water runoff from the standard land-management basin and that from the conservation land-management basin. Concentrations of the soil pesticides isopropalin and flumetralin were higher in the standard land-management basin than in the conservation land-management basin.
