Seasonal Runoff and Nutrient Transport from St. Augustinegrass Turf.

The fate of nutrients applied to turf has been an ongoing area of research.  In Texas, surface runoff from residential lawns has emerged as a possible source of N in urban watersheds.   Irrigation and fertility management can affect nutrient availability to turfgrasses and environmental pollution in urban waterways.  Specifically, deficit irrigation practices could reduce the N assimilatory capacity of turfgrasses, thereby increasing the potential for N escape. Thus, a field study was initiated at the Texas A&M Surface Runoff Facility in College Station, TX, to measure runoff volumes and nutrient loading from St. Augustinegrass (Stenotaphrum secundatum (Walter) Kuntze) lawns as influenced by three levels of irrigation and three levels of nitrogen fertility.  The preliminary findings suggest that seasonal variability in temperature, soil moisture, and rainfall have a larger effect on N flux than does summer irrigation or fertility management.