Evaluation of a soil moisture sensor to reduce water and nutrient leaching in turfgrass (Cynodon dactylon cv. Wintergreen)

Abstract

This study evaluated water application rates, leaching and quality of couch grass (Cynodon dactylon cv. Wintergreen) under a soil moisture sensor-controlled irrigation system, compared with plots under conventional irrigation scheduling as recommended for domestic lawns in Perth, Western Australia by the State’s water supplier. The cumulative volume of water applied during summer to the field plots of turfgrass with the sensor-controlled system was 25% less than that applied to plots with conventional irrigation scheduling. During 154 days over summer and autumn, about 4% of the applied water drained from lysimeters in sensor-controlled plots, and about 16% drained from lysimeters in plots with conventional irrigation scheduling. Even though losses of mineral nitrogen via leaching were extremely small (representing only 1.1% of the total nitrogen applied to conventionally irrigated plots), losses were significantly lower in the sensor-controlled plots. Total clippings produced were 18% lower in sensor-controlled plots. Turfgrass colour in sensor-controlled plots was reduced during summer, but colour remained acceptable under both treatments. The soil moisture sensor-controlled irrigation system enabled automatic implementation of irrigation events to match turfgrass water requirements.