Soil Moisture Sensor Landscape Irrigation Controllers: A Review of Multi-Study Results and Future Implications

Abstract

This is a review article with the objective of summarizing and relating the main findings of different research projects carried out in Florida that evaluated commercially available soil moisture sensor systems (SMSs) for residential irrigation control. The initial goal of the experiments cited was to find out if SMSs could reduce irrigation water application as compared to typical residential irrigation systems without sensor feedback. The effect of different threshold settings and irrigation frequencies on water application and turf quality was also evaluated. Other research goals included evaluating the consistency of different SMS units and their precision in measuring soil water content (θ). Results on turfgrass plots showed that a 7 days per week (d week -1 ) irrigation frequency significantly reduced the water applied compared to 1 and 2 d week -1 scheduled frequencies. During rainy periods, the SMSs tested reduced irrigation by 42% to 72% on average, depending on specific testing conditions, while maintaining good turf quality. During dry periods, the average savings decreased to -1% to 64%, and the resultant turf quality was sometimes below the minimum acceptable level. Therefore, under sustained dry weather conditions or in dry climates, the run times, irrigation frequency, and/or low threshold settings should be carefully considered. Results showed that SMSs from Acclima and Rain Bird were more consistent and precise in measuring soil water content and saved more water than Water Watcher and Irrometer units. Under residential conditions, SMSs decreased the water application by 65% compared to homes with automated irrigation systems without sensor feedback. Overall research results clearly demonstrate that the use of SMSs in Florida, when properly installed, set, and maintained, could lead to significant irrigation water savings while maintaining turf quality at or above the minimum acceptable rating.

Soil Moisture Sensor Irrigation Controllers and Reclaimed Water; Part I: Field-plot Study

“…A low MAD factor of 0.3 was chosen as suggested by previous studies in sandy soils (Cardenas-Lailhacar and Dukes, 2012).…”

“…In Florida and North Carolina, research on turfgrass plots under normal to wet weather conditions have resulted in water savings between 39% and 72%, without compromising the turfgrass quality (Cardenas-Lailhacar et al, 2008;McCready et al, 2009;Cardenas-Lailhacar and Dukes, 2012;Grabow et al, 2013). However, during sustained dry weather conditions, lower water savings were obtained (-1% to 64%).…”

Relating Knowledge and Perceptions of Sustainable Water Management to Preferences for Smart Irrigation Technology

“…Thus, residential irrigation efficiency is imperative when considering sustainable water management in urban areas. Well-managed residential landscapes enhance the urban environment and provide economic, environmental and lifestyle/health benefits including erosion/dust control, ground/surface water quality protection, urban heat/noise studies focus on performance factors and their water saving potential [15,27,29,30]. In contrast, very few studies have addressed consumers' knowledge of smart irrigation technology and how that influences their purchasing/implementation behavior.…”

An Automated Irrigation System for Greenhouses

“…Proper irrigation is key to improve quality and productivity of crops grown in greenhouses [3]. The time, duration, type and amount or irrigation are essential to optimize the use of water [4,5,6,7,8].…”