Soils--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.