Submitted to: Applied Engineering in Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/20/2013
Publication Date: 5/1/2013
Citation: Saia, S.M., Brooks, E.S., Easton, Z.M., Baffaut, C., Boll, J., Steenhuis, T.S. 2013. Incorporating pesticide transport into the WEPP-UI Model for mulch tillage and no tillage plots with an underlying claypan soil. Applied Engineering in Agriculture. 29(3):373-382. Interpretive Summary: Soil and water managers need practical tools to help them select best management practices that reduce dissolved and sediment bounds pesticides from agricultural fields. The suggestions provided by these tools need to be site-specific and low in required input data. The Watershed Erosion Prediction Project University of Idaho (WEPP-UI) pesticide transport module is an extension of the WEPP model that includes pesticide transport. It can simulate the effects of tillage, vegetated buffer strips, and precision pesticide application rates on various sections of the hillslope. In this study, the WEPP-UI pesticide transport module was used to simulate dissolved atrazine loads from mulch-till (MT) and no-till (NT) plots located in the Goodwater Creek Experimental Watershed, in northern Missouri, and compare them to measured data. Simulated loads were under-predicted for MT plots and well predicted for NT plots. While this study focused on dissolved pesticide transport at the bottom of a hillslope, the WEPP-UI pesticide transport module has the capacity to predict loads from each section of the slope (i.e. top, middle, and bottom) including sediment bound pesticide loads. These results contribute to the validation of the WEPP-UI model at various sites across the United States and will be useful to scientists or soil and water managers in need of evaluating this tool for its ability to simulate herbicide transport and the effectiveness of management practices.
Technical Abstract: Best management practice (BMP) selection tools that provide site-specific management suggestions with limited input data are needed to assist soil and water managers in their efforts to reduce dissolved and sediment bound pesticide loads from agricultural landscapes. In this study, we simulate dissolved atrazine loads from the toe-slope of mulch till (MT) and no till (NT) plots using the Watershed Erosion Prediction Project University of Idaho (WEPP-UI) model to field data taken from the Goodwater Creek Experimental Watershed of northern Missouri. Seasonal dissolved atrazine loads are under predicted for MT plots and reasonably well predicted for NT plots. In addition to MT and NT, the WEPP-UI pesticide transport module can simulate the impacts of vegetated buffer strips and precision pesticide application rates. While this study focuses on dissolved pesticide transport at the bottom of a hillslope, the WEPP-UI pesticide transport module has the capacity to predict loads from each section of the hillslope (i.e. top-slope, mid-slope, and toe-slope); including sediment bound pesticide loads. More extensive field monitoring is needed to validate these results.