Potential Movement of Pesticides Related to Dissolved Organic Matter from Fertilizer Application on Turf

Turf grass systems - including golf courses, turf farms, parks and lawns - are the most intensively managed lands in the United States. Establishment and maintenance of high quality turf grass usually imply substantial inputs of water, nutrients, and pesticides. The impacts of these inputs to groundwater and surface water are a major concern of public and government agencies with over 17,816 golf courses in the U.S. and more than one new golf course opening every day (National Golf Foundation, 2002). Recent results from various facets of agricultural research have indicated very significant effects of dissolved organic matter (DOM) on the increased mobility of pesticides through soils to groundwater. These findings may have important ramifications to the golf turf industry in that the frequent use of certain organic fertilizers and amendments may actually enhance rather than inhibit movement of certain pesticides through highly managed greens and tee areas having a high level of sand incorporated into profiles. This is not only a regional, but also a national problem. The Northeast is more susceptible due to the coarse texture of soils in general. There is a significant amount of research devoted to the efficacy of organic fertilizers currently on the market such as NatureSafe, Milorganite, Sustain and Ringers, some containing as much as 3.5 % DOM (water extraction). Organic fertilizers are considered slow release materials with low burn potential and are often applied at higher rates compared with soluble inorganic fertilizers. Higher application rates could easily result in higher loading of DOM into soil profiles. In addition, high density and much more root turnover in turf grass ecosystems could directly contribute to the pool of natural DOM, which could affect the behavior of pesticides in soil and water