|Horgan, Brian - UNIVERSITY OF MINNESOTA|
Submitted to: Trade Journal Publication
Publication Type: Research Notes
Publication Acceptance Date: November 20, 2006
Publication Date: November 30, 2006
Citation: Rice, P.J., Horgan, B.P. 2006. Reducing Pesticide and Nutrient Loads with Runoff from Fairway Turf Utilizing Management Practices. USGA Turfgrass and Environmental Research Summary. p. 49. Available: http://www.lib.msu.edu/tgif/usgasummarybrowse.htm. Technical Abstract: Water quality surveys have detected excess nutrients and multiple pesticides in surface waters of urban and rural areas. As a result, attempts are being made to identify the sources of these compounds and reduce their inputs. The use of fertilizers and pesticides in highly managed turf systems has raised questions concerning the contribution of runoff from managed turf. To address these questions we designed experiments to measure the quantity of fertilizers and pesticides transported with runoff from turf plots managed as a golf course fairway (1.25 cm height of cut), and to evaluate the ability of chemical application strategies and cultural practices to reduce the transport of applied chemicals with runoff. Chemical application strategies were evaluated with conservative-tracers, compounds historically utilized as hydrologic tools for characterizing water movement through soil. Selective application of multiple fluorobenzoic acids and potassium bromide to the turf plots enabled identification of areas that contribute the most to chemical transport with runoff and provide information to determine chemical application strategies to reduce off-site transport of applied compounds. Cultural practices assessed to determine their capacity to reduce surface runoff and chemical transport with runoff included aeration with hollow or solid tines and the influence of vertical slicing to manage thatch and increase infiltration. In 2005, half of the plots received solid-tine aeration while the remaining plots were managed with hollow-tine aeration. Fertilizer (18-3-18 [N, P2O5, K2O]) and a commonly utilized herbicide (2,4-D), insecticide (chlorpyrifos), and fungicide (flutolanil) were applied to each plot 24 hours prior to the intiation of the simulated precipitation. Preliminary results for fertilizer transport show reduced runoff volume, nitrogen loss and phosphorus loss with hollow-tine aeration relative to solid-tine aeration. Completion of pesticide analysis and statistical analysis of fertilizer and pesticide data will determine the statistical relevance of the initial observed trends. For 2006, an additional cultural practice was evaluated. All turf plots were initially managed with hollow-tine aeration and sand topdressing. Seven days prior to the second rainfall simulation, half of the plots also received vertical slicing to increase water infiltration and further manage the thatch. Chemical application, rainfall simulation, and sample collected followed the same protocol initiated in 2005. Infiltration measurements revealed the implementation of vertical slicing enhanced water infiltration. Analysis of runoff water will determine the influence of enhanced infiltration on runoff volumes and quantities of chemicals transported with the runoff. Identifying practices that reduce off-site transport of applied chemicals will increase fertilizer and pesticide efficacy at the intended sites of application and minimize their potential adverse impacts to the surrounding surface water resources. Results of this research will provide information that will allow for informed decisions on best management practices that are both environmentally responsible and provide quality turf.