Water Quality Impacts Associated with Converting Farmland and Forests to Turfgrass

Three to four hundred new or renovated turfgrass systems are constructed in the U.S. each year. Many of these systems (golf courses, city parks, and residential and institutional lawns) are constructed in agricultural and silvicultural environments. However, knowledge of the water quality impact in transitioning from an agricultural or silvicultural landscape to a turfgrass landscape is at best limited. Using the Soil Water Assessment Tool (SWAT) water quality model, 99–year simulations for three locations were completed for a continuous corn (Zea mays L.) agricultural rotation (AGR), a forested environment (FST), a golf course built in a previously agricultural setting (AGR–G), and a golf course constructed in a previously forested (FST–G) setting. Hydrologic, nitrate–nitrogen, and pesticide (2,4–Dichlorophenoxyacetic acid) impacts were evaluated. The hydrologic balance associated with AGR was significantly different from those for AGR–G, FST–G, and FST. Transition from FST to FST–G increased the loading and risk potential of surface runoff losses for both nitrate and 2,4–D and significantly increased ( = 0.05) the potential for percolate losses of 2,4–D. Converting AGR to AGR–G significantly reduced the loading and risk potential for nitrate and 2,4–D losses. However, the addition of housing developments and increased impervious areas, which generally follow turfgrass land developments, were not considered, so the actual risk potential is probably higher than shown with this model. In addition to the impacts assessed, this study shows the SWAT model and associated simulation and analysis strategy to be a useful tool in evaluating risk assessments associated with land use conversions.