Return on investment and water savings of add‐on irrigation sensors for bermudagrass lawn irrigation in Northwest Arkansas

Abstract

AbstractHomeowners with automated sprinkler systems water lawns frequently and may be unaware of the volume of water applied in their irrigation programs. Rain sensors (RS) and soil moisture sensors (SMS) may reduce watering by permitting scheduled irrigation to occur relative to recent rainfall or current soil moisture status and are available as add‐on technologies for residential sprinkler systems. As RS and SMS may positively impact irrigation scheduling, incorporating them into existing sprinkler systems may reduce water use and provide a return on investment (ROI), without compromising turfgrass quality. The objectives of this research were to determine the water savings of add‐on RS and SMS, estimate their ROI, and evaluate their impact on bermudagrass [Cynodon dactylon (L.) Pers.] lawn quality over three summers in Northwest Arkansas. An irrigation schedule without a sensor (control) was programmed to apply 0.5 inches of water twice a week for 17 wk. Water usage and turfgrass quality under the control were compared with two RS and two SMS, following the same program. During the 3‐yr study, RS and SMS reduced annual water use by an average of 22.1 and 66.2%, respectively. All treatments exhibited similar turfgrass quality and remained above the minimum level of acceptable quality. Under these experimental conditions, the average ROI for RS and SMS was estimated to be $87 and $200, respectively, within the first year of installation. Regional best management practices for watering bermudagrass lawns should include the incorporation of RS and SMS to reduce irrigation, maintain turfgrass quality, and save money.