Wednesday, November 7, 2007 - 1:45 PM
269-3
Nitrogen Losses from Warm-season Turfgrasses.
An anthropogenic doubling of global nitrogen (N) inputs into terrestrial systems and associated potential N leaching from soils has been cited as a principal cause of increased N movement into rivers, estuaries, springs and coastal oceans, often causing eutrophication and other environmental problems. Nitrogen use for turfgrass establishment and maintenance frequently is assumed to be a major contributor to N leaching, particularly in urban environments, and turfgrass N fertilization regulatory efforts are being enacted. As a result, alternatives to turfgrass landscapes have been promoted. Since warm-season turfgrasses often are grown in environments with an extended growing season, greater amounts of N may be used for their production and maintenance than are used for their cool-season counterparts. Significant nitrogen leaching has been documented under conditions of high N fertilization. However, warm-season grasses have the capacity to absorb considerable N, with some species being better than others. It has been demonstrated under a variety of conditions that applying N in a manner that does not exceed the absorption capacity of the grass, and irrigating to limit percolation, can result in quality warm-season turf with minimal N leaching. Nitrogen leaching from turfgrass has been demonstrated to be less than that from alternative mixed-species landscapes, particularly in the first few years of establishment. Strategies for minimizing N leaching from turfgrass generally involve such techniques as limiting rates of application, timing applications to correspond to turfgrass growth and coverage, controlled-release fertilizers, fertigation, and irrigation management. Fortunately, the goal of minimizing N losses generally augments the goal of achieving quality turfgrass.
Audio File