Developing Urban Irrigation Water Conservation Strategies Using Smart Soil Moisture Sensor-Based Controllers.

The recent five-year drought coupled with water distribution issues and the increasing urban population throughout California underscore the high priority of efficient urban irrigation in California as well as other fast-growing metropolitan areas in western US. As the drought conditions persist and water continues to become less available, the development of methods to reduce water inputs is extremely important. There are promising reports in the literature regarding the use of smart irrigation technologies to enhance irrigation management and significant water savings have been reported as a result of implementing these technologies for landscape irrigation management mainly in humid regions. There remains the necessity to evaluate the efficacy of these technologies for irrigation water conservation in arid regions that is expected to reduce water waste and improve irrigation water use efficiency, which is the main objective of this study.

A turfgrass irrigation experimental trial is being conducted at the University of California-Riverside Agricultural Experiment Station. A total of 48 plots (3.7 m × 3.7 m) were established to tall fescue grass using sod in early May 2017. The study involves 12 irrigation treatments replicated 4 times in a complete randomized block design. Each plot is irrigated by 4 quarter-circle, pop-up heads, sprinklers controlled by a common solenoid valve. Multiple commercial soil moisture based smart irrigation controllers are being used to apply a variety of irrigation scenarios. Our team will monitor the effectiveness of these technologies and evaluate the impacts of deficit irrigation on turf health and quality and irrigation water use efficiency. We will use a variety of sensors and novel remote sensing approaches to detect and measure drought injury to turfgrass. This project promotes adoption of turf irrigation water conservation strategies to keep the plants alive and/or sustain the desired quality with minimum water.