Submitted to: Journal of the American Water Resources Association
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/20/2000
Publication Date: 6/20/2001
Citation: King, K.W., Harmel, R.D., Torbert, H.A., Balogh, J.C. Impact of a turfgrass system on nutrient loading to surface water. Journal of the American Water Resources Association. 2001. v. 37(3). p. 629-640. Interpretive Summary: The number of golf courses in the U.S. is increasing at an unprecedented rate. In order to maintain the turf system, a relatively large mass of fertilizers when compared to typical agriculture is used. The impact of those fertilizers has only been evaluated on small field or plot scales managed as a single unit. This study investigated the offsite transport of nitrogen and phosphorus from a whole turfgrass system, which contains a full spectrum of management. The primary findings of the study indicated that this turf system did add nitrate nitrogen to the stream through both storm flow and base flow. However, the loading rates were generally less than screening levels. These findings suggest that improvements could be made with respect to fertilizer management on turf systems.
Technical Abstract: Turfgrass systems, including turf farms, golf courses, city parks, and residential and institutional lawns, are one of the most intensively managed land uses in the U.S.A. Establishment and maintenance of high quality turfgrass requires substantial inputs of water, nutrients, and pesticides. The focus of this work was to quantify the concentration and loading of a well-maintained turfgrass environment on surface water. Wate quantity and quality data were collected from a turfgrass system in Austin, Texas, and analyzed for a 13-month period from 20 March 1998 to 30 April 1999. Seventeen precipitation events greater than 6.4 mm totaled 681 mm and produced an estimated 161 mm of runoff. Nutrient concentrations in surface runoff exiting the course exhibited a statistically significant (p less than 0.05) increase in nitrate plus nitrite nitrogen (NO3+NO2-N) compared to runoff entering the course, a statistically significant decrease in ammonia nitrogen (NH4-N), but no difference in ortho-phosphate (PO4-P). During the 13-month period, storm runoff contributed an estimated 6.4 kg ha**-1 (5.9 kg ha**-1 yr**-1) of NO3+NO2-N and 1.4 kg ha**-1 (1.3 kg ha**-1 yr**-1) of PO4-P to the stream and a decrease of 0.3 kg ha**-1 (0.3 kg ha**-1 yr**-1) of NH4-N. Baseflow nutrient concentration data showed a statistically significant increase in NO3+NO2-N (+0.9 mg L**-1), a significant reduction in NH4-N (-0.1 mg L**-1), and no change in PO4-P. Even though nutrient concentrations exiting the system rarely exceeded nutrient screening levels, this turfgrass environment did contribute increased NO3+NO2-N levels to the stream. This emphasizes the need for golf course managers to utilize an integrated management program to protect water quality while maintaining healthy turfgrass systems.