Influence of Gypsum and Wetting Agent on Sand-Based Putting Greens Irrigated with Recycled Wastewater

Recycled wastewater (RW) is a source of irrigation for golf courses in many parts of the world. The objectives of this study were to determine the effects of gypsum and wetting agent applications on the turfgrass quality, clipping yield, root zone chemical and physical properties, and leachate of a sand-based putting green irrigated with secondary and tertiary RW. Our results showed that gypsum amendment produced better turfgrass quality under summer heat stress than the wetting agent and the control. Soil water infiltration was impeded by secondary and tertiary RW but was improved by the gypsum treatments. When compared with topdressing with straight sand, the wetting agent application did not improve turfgrass quality or soil properties when irrigated with RW. Monthly applications of a wetting agent resulted in lower water infiltration rates, but the values remained within the U.S. Golf Association recommendations for putting green construction. Golf course superintendents are encouraged to use gypsum when managing sand-based putting greens with RW as the primary source of irrigation water.