Impact of Reuse Water on Golf Course Soil and Turfgrass Parameters Monitored Over a 4.5-Year Period

Population growth and water limitations in the southwestern United States have led to golf courses in many communities to be encouraged or mandated to transition to reuse water for irrigation purposes. A monitoring program was conducted on nine golf courses in the Las Vegas valley, NV, for 4.5 years to assess the impact of reuse water on soil-turfgrass systems {bermudagrass (Cynodon dactylon (L.) Pers.), perennial ryegrass (Lolium perenne L.), bentgrass (Agrostis palustris Huds.)}. The nine courses selected included three long-term reuse courses, three fresh water courses, and three courses expected to transition to reuse water during the monitoring period. Near-surface soil salinity varied from 1.5 to 40.0 dSm -1 during the study period with the highest peaks occurring during summer months and on long-term reuse irrigated fairways. Although soil salinity at several depths on fairways and greens increased after transition to reuse water, this did not lead to a systematic decline in leaf xylem water potential (CL) or color. When the data were grouped as fresh, transition, or reuse irrigated, soil salinity on reuse courses were statistically higher (P 0.05) than that observed on fresh courses. The fact that summertime plant parameter values often declined under lower salinity levels and the electrical conductivity of the irrigation water was rejected as a significant variable in all backward regression analysis to describe plant response indicated that management differed significantly from course to course. We conclude that proper irrigation management, based on a multitiered feedback system (soil-plant- atmospheric monitoring), should be able to maintain favorable salt balances and plant response as long as irrigation volumes are not restricted to where deficit irrigation occurs.