What is the nitrogen threshold that may compromise water quality standards in runoff?
Limited research exists relative to runoff from Florida turfgrasses. Based on the current research data available, runoff from healthy turfgrass growing on a 10 percent slope was limited to an extreme hurricane event when excessive rainfall occurred (Erickson et al., 1999; Erickson et al., 2001). The water that was collected in the runoff from the turfgrass actually contained less N than did the rainfall. It has also been reported that only 0.03 percent of the applied N was collected in an excessively irrigated bermudagrass during grow-in on a 10 percent slope (Shaddox & Sartain, 2000). Thus, it appears based on these studies that very little if any nitrogen, when applied at IFAS-recommended rates, moves across the surface of a healthy turfgrass, and there is very little threat of water quality compromise as a result of runoff. Other potential sources of nitrogen found in waterways include pet feces and septic tanks in landscapes.
