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The use of effluent water on landscapes and in agriculture to reduce fresh water consumption has increased in recent years. However, it has recently been reported that the use of effluent water can increase water repellency in soils (Wallach et al., 2005). Soil water repellency (SWR) reduces water movement into and through soils, creates preferential flow paths, increases leaching of pesticides and fertilizers, reduces water use efficiency and significantly reduces turfgrass and crop quality. Soil surfactants have been used in the horticulture and turfgrass industries to aid water movement through a soil profile and reduce soil water repellency. The objective of this study was to determine if two novel surfactant technologies addressed the issues of SWR on a golf course in Florida, USA that had been irrigating with effluent water for more than five years. Two surfactant treatments, an alkyl-polyglycoside blended with an ethylene oxide-propylene oxide block (APG) and a methyl capped ethylene oxide-propylene oxide block (MC) soil surfactant, were applied monthly. Turfgrass quality, localized dry spot (LDS), volumetric water content (VWC) and soil water repellency (SWR) data were collected and analyzed over a two year period. Overall, surfactant treatments improved turfgrass quality, reduced LDS, increased VWC and reduced SWR when compared to the control treatment. The APG chemistry significantly enhanced turfgrass quality, reduced LDS and increased VWC when compared to the MC treatment. The MC chemistry significantly reduced SWR when compared to the APG chemistry. Based on these results, surfactants are an effective tool to maximize water use efficiency, improve the aesthetic appearance of turfgrass and ameliorate SWR but the surfactant chemistry determines the extent of the benefits. This study also determined that water repellency was severe on an effluent irrigated golf course but the cause of the hydrophobicity may not necessarily be attributed to effluent water usage. |