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 thesesystems (golf courses, city parks, and residential and institutional lawns) are constructed in agricultural and silviculturalenvironments. However, knowledge of the water quality impact in transitioning from an agricultural or silvicultural landscapeto a turfgrass landscape is at best limited. Using the Soil Water Assessment Tool (SWAT) water quality model, 99yearsimulations for three locations were completed for a continuous corn (Zea mays L.) agricultural rotation (AGR), a forestedenvironment (FST), a golf course built in a previously agricultural setting (AGRG), and a golf course constructed in apreviously forested (FSTG) setting. Hydrologic, nitratenitrogen, and pesticide (2,4Dichlorophenoxyacetic acid) impactswere evaluated. The hydrologic balance associated with AGR was significantly different from those for AGRG, FSTG, andFST. Transition from FST to FSTG increased the loading and risk potential of surface runoff losses for both nitrate and 2,4Dand significantly increased (
= 0.05) the potential for percolate losses of 2,4D. Converting AGR to AGRG significantlyreduced the loading and risk potential for nitrate and 2,4D losses. However, the addition of housing developments andincreased impervious areas, which generally follow turfgrass land developments, were not considered, so the actual riskpotential is probably higher than shown with this model. In addition to the impacts assessed, this study shows the SWAT modeland associated simulation and analysis strategy to be a useful tool in evaluating risk assessments associated with land useconversions.