Does residential landscape type affect nitrogen runoff and leaching?

Intensely maintained turfgrass landscapes have some potential for loss of fertilizer nitrogen (N) in both runoff and leaching. Lower maintenance vegetation used in mixed-species landscapes may reduce N leaching and runoff, which is important for reducing environmental pollution of surface and ground waters. However, few studies have examined this paradigm. Therefore, we constructed a field-scale facility to compare fertilizer N runoff and leaching between St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze cv. 'Floratam') and a mixed-species landscape designed by the Florida Yards and Neighborhoods (FYN) program. A blended granular fertilizer was applied at a rate of 300 and 150 kg N ha-1 yr -1 on the turfgrass and mixed-species, respectively. During the 12-month study only one minor runoff event occurred (<0.2 cm) and N losses were insignificant. Annual N leaching losses were significantly greater on the mixed-species landscape, resulting in 4.80 g N m-2 compared to 0.41 g N m-2 for the St. Augustinegrass.