Many golf courses in the southwestern United States are transitioning to reuse water for irrigation purposes. In Las Vegas, NV, 30 of 53 golf courses now irrigate with reuse water. As communities grow in size, the amount of reuse water generated also increases (Devitt et al., 2007). Using reuse water for golf courses and urban landscapes is an environmentally preferred alternative to discharging such waters back into rivers and lakes. However, care must be taken when irrigating with reuse water because it carries a significant salt and nitrogen load. Although the nitrogen load should be viewed as a positive trait for turfgrass managers, it does mean that conventional applications of nitrogen must be properly adjusted. Nitrogen concentrations typically remain fairly high on a year-round basis in reuse water (Feigin et al., 1991). Thus, as irrigation levels go up in the summer months, so does the nitrogen loading. Bermudagrass in particular is known for its high nitrogen uptake rates (Bowman et al., 2006; Feigin et al., 1991; Fonseca et al., 2007; Olsen and Kurtz, 1982). If irrigations are excessive, nitrate–nitrogen is prone to leaching (Brown et al., 1982; Devitt et al., 1976; Feigin et al., 1991; Letey et al., 1977; Snyder et al., 1981). However, many turfgrass studies under fresh water irrigation have reported low nitrate–nitrogen (NO3-N) leaching, especially with bermudagrass (Snyder et al., 1984, Wu et al., 2007), whereas Bowman et al. (2006) found that under various levels of stress, nitrogen (N) use efficiency declined for several turfgrass species, leading to elevated N leaching losses. Regulatory agencies such as the Nevada Department of Environmental Protection require quarterly reporting of the amount of reuse water used and the amount of N applied. Irrigating with waters that have elevated salinity levels requires that a leaching fraction be incorporated into the long-term irrigation management plan. Because irrigation systems do not deliver water in a perfectly uniform fashion, irrigation must be applied at a rate beyond actual evapotranspiration to compensate for this nonuniformity while also achieving acceptable leaching. In Las Vegas, NV, a minimum leaching fraction of 0.15 associated with yearly soil sampling to assess salt buildup is recommended. In a previous study (Devitt et al., 2007), we reported that only four of nine golf courses monitored maintained positive field-based leaching fractions (LFs) in all 4 years. Irrigators must maintain a delicate balance between maintaining favorable salt balances while minimizing NO3-N leaching. Because of environmental concerns over the fate of N in reuse water applied to golf courses, we measured NO3-N concentrations in the soil solution at four depths on a monthly basis over a 1600-d period. Results reported here are part of a larger study (Devitt et al., 2004, 2005, 2007). The objectives of this phase of the study were to 1) compare and contrast the NO3-N concentrations below reuse irrigated fairways with fairways that transitioned to reuse water; and 2) determine if fundamental relationships existed among the amount of N applied (reuse N plus fertilizer N), the LF, and the NO3-N concentrations in the soil solution.
Anderson, E.L., Pepper, I.L. & Kneebone, W.R. 1981 Reclamation of wastewater with a soil turf filter: 1: Removal of nitrogen Journal WPCF 53 1402 1407
Barton, L., Schipper, L.A., Barkle, G.F., McLeod, M., Speir, T.W., Taylor, M.D., McGill, A.C., Van Schaik, A.P., Fitzgerald, N.B. & Pandey, S.P. 2005 Land application of domestic effluent onto four soil types: Plant uptake and nutrient leaching J. Environ. Qual. 34 635 643
Bowman, D.C., Devitt, D.A., Engelke, M.C. & Rufty, T.W. Jr 1998 Root architecture affects nitrate leaching from bentgrass turf Crop Sci. 38 1633 1639
Bowman, D.C., Devitt, D.A. & Miller, W.W. 2006 The effect of moderate salinity on nitrate leaching from bermudagrass turf: A lysimeter study Water Air Soil Pollut. 175 49 60
Brown, K.W., Thomas, J.C. & Duble, R.L. 1982 Nitrogen source effect on nitrate and ammonium leaching and runoff losses from greens Agron. J. 74 947 950
Devitt, D.A., Letey, J., Lund, L.J. & Blair, J.W. 1976 Nitrate–nitrogen movement through soil as affected by soil profile characteristics J. Environ. Qual. 5 283 288
Devitt, D.A., Lockett, M., Morris, R.L. & Bird, B.M. 2007 Spatial and temporal distribution of salts on fairways and greens irrigated with reuse water Agron. J. 99 692 700
Devitt, D.A., Morris, R.L., Baghzouz, M. & Lockett, M. 2005 Water quality changes in golf course irrigation ponds transitioning to reuse water HortScience 40 2151 2156
Devitt, D.A., Morris, R.L. & Bowman, D.C. 1992 Evapotranspiration, crop coefficients and leaching fractions of irrigated desert turfgrass systems Agron. J. 88 844 849
Devitt, D.A., Morris, R.L., Kopec, D. & Henry, M. 2004 Golf course superintendent's attitudes and perceptions toward using reuse water for irrigation in the southwestern United States HortTechnology 14 1 7
EPA. 1992. Guidelines for water reuse. EPA/625/R-92/004.
Feigin, A., Ravina, I. & Shalhevet, J. 1991 Irrigation with treated sewage effluent: Management for environmental protection Springer-Verlag Berlin, Germany
Fonseca, A.F., Melfi, A.J., Monteiro, F.A., Montes, C.R., Almeida, V.V. & Herpin, U. 2007 Treated sewage effluent as a source of water and nitrogen for Tifton 85 bermudagrass Agr. Water Mgt. 87 328 336
Kopp, K.L. & Guillard, K. 2005 Clipping contributions to nitrate leaching from creeping bentgrass under varying irrigation and N rates Int. Turfgass Soc Res J. 10 80 85
Letey, J., Blair, J.W., Devitt, D., Lund, L.S. & Nash, P. 1977 Nitrate–nitrogen in effluent from agricultural tile drains in California Hilgardia 45 289 319
Lockett, M. 2008 Quantifying the impact of reuse water on the soil and turfgrass quality of golfcourses. Water resource management University of Nevada Las Vegas MS Thesis.
Mancino, C.F. & Troll, J. 1990 Nitrate and ammonium leaching losses from N fertilizers applied to ‘Pencross’ Creeping Bentgrass HortScience 25 194 196
McLeod, M., Schipper, L.A. & Taylor, M.D. 1998 Preferential flow in a well drained and a poorly drained soil under different overhead irrigation regimes Soil Use and Management 14 96 100
Nevada Division of Environmental Protection. 2007. Dec. 2007. <http://ndep.nv.gov/index.htm>.
Olsen, R.A. & Kurtz, L.T. 1982 Crop nitrogen requirements, utilization and fertilization 597 604 Stevenson F.J., Nitrogen in agricultural soils Amer. Soc Agron
Snyder, G.H., Augustin, B.J. & Davidson, J.M. 1984 Moisture sensor-controlled irrigation for reducing N leaching in bermudagrass turf Agron. J. 76 964 969
Snyder, G.H., Burt, E.O. & Davidson, J.M. 1981 Nitrogen leaching in bermudagrass turf: 2. Effect of nitrogen sources and rates 313 324 Sheard R.W. Proc. 4th Int. Turfgrass Res. Conf University of Guelph Ontario, Canada, 1980