Effect of Surfactant and Deficit Irrigation on Water and Nutrient Retention in Simulated Urban Lawns.

Loss of nutrients and water from urban lawns has increased in recent years due to increasingly limited water supply. The use of surfactant has become more widespread, especially on golf courses and sports fields to increase water infiltration into turf covered areas. Therefore, there is an interest in expanding their use to home lawns. The objective of this study was to determine the efficacy of regular applications of a surfactant in reducing the volume of runoff emanating from St. Augustine turfgrass covered simulated home lawns and its benefit to soil moisture content. The effect of surfactant and deficit irrigation on Nutrient retention and turf quality were also evaluated. This study was conducted at the Texas A&M Turf Field Laboratory in College Station, TX using the existing urban runoff research facility. 24 plots which each has a size of 13 ft. wide by 26 ft. long with a 3.5% slope and individual irrigation control were allotted to 5 different treatments. They are combinations of irrigation levels (30%, 60% ET_o), fertilizer (+/-), and surfactant (+/-). Runoff water samples (pH, EC, et al.), soil moisture content, and percent green cover were collected to provide the best management of surfactants, fertilization and irrigation on urban home lawns. Results showed that the effect of surfactant, fertilizer, and irrigation on soil moisture content is negligible, comparing to the effect of rain event. However, percent green cover is significantly affected by surfactant.