COMPARISON OF SUBSURFACE DRIP IRRIGATION AND SPRINKLER IRRIGATION FOR BERMUDA GRASS TURF IN ARIZONA

摘要

A subsurface drip irrigation (SDI) system is potentially efficient because it provides water directly to the root zone, minimizing evaporative loss, especially in arid lands. In this study, subsurface drip irrigation was compared to standard overhead sprinkler irrigation of Bermuda grass turf using reclaimed water. Research focused on the response of Bermuda grass to two irrigation treatments, subsurface drip irrigation and overhead sprinkler irrigation. Soil moisture content was calculated via time domain reflectometry (TDR) and neutron probe data. The remotely sensed crop water stress index (CWSI) could not be used to schedule irrigation. When the average soil moisture of all eight plots was depleted to 50% of readily available water, they were irrigated until the soil moisture content reached field capacity. No significant differences were observed between the two irrigation systems in total irrigation depth, relative root weight, dry clipping mass per unit area, or visual quality. The electrical conductivity (EC) of a soil water extract measured at the beginning and end of the season indicated salt accumulation near the ground surface in the subsurface plots, but there was not sufficient accumulation to affect the appearance of turf. Visual inspection of emitters after one irrigation season showed signs of root intrusion because of water stress in certain plots with high surface sand content.