Agricultural Land Use: Effects on the Chemical Quality of Runoff

摘要

This research focused on changes in runoff quality when land is put under cultivation. The data will be used in later phases of research to evaluate chemical transport models. The 3 study watersheds, located in Virginia's southern Piedmont, had not been under cultivation for 30 years. During the research, 2 of the watersheds were put into agricultural production while the third was left uncultivated and used as a control. A grab sampling program was maintained on 2 watersheds for the full 5-year study period. Continuous streamflow gaging was maintained for the last 4 years. During the final 3 years, sampling and flow gaging were also maintained on a third watershed. Samples were analyzed for nitrate, ammonium, and total Kjeldahl nitrogen, orthophosphate and total phosphorus, bicarbonate alkalinity, pH, and specific conductance. Clear differences in streamflow characteristics were noted between the treated and the control watersheds. More surface runoff was observed in the treated watersheds than in the control, suggesting that increased surface runoff may have resulted from the cropping activity.