Two Decades of Smart Irrigation Controllers in U.S. Landscape Irrigation

Abstract

HighlightsSavings numbers in new studies across multiple soil types and climates are similar to those summarized in 2011 and are summarized here as 51% in research plot studies and 30% in single-family homes.Studies of the human factors have begun showing how important the users are to success of the technology.Education in implementation remains important to achieve potential water conservation.Abstract. Smart irrigation controllers, such as evapotranspiration (ET) and soil moisture sensor (SMS) controllers, have become commonly available from virtually all irrigation controller manufacturers. This review summarizes the literature since the Fifth Decennial National Irrigation Symposium (NIS) concerning these controllers in research studies and pilot implementations. Studies have expanded to multiple climates throughout the U.S. on a variety of soils and plant types. When these devices are implemented properly on sites that have potential irrigation savings (i.e., excess irrigation), they are able to reduce irrigation while maintaining plant quality. The level of reduction depends on many factors, including the amount of excess irrigation, climate, plant type, and human interaction with the technology. When studies report positive savings, the levels documented here range from 40% to 61% (51% avg.) in plot studies and from 28% to 32% (30% avg.) in residential studies. Of 17 identified studies in the past decade, five reported negative savings, and in most cases those results were due to ET controllers installed on sites with little excess irrigation or controller programming that was not optimized for savings. New trends in the industry include Wi-Fi signal-based ET controllers with smartphone app capability, an upcoming standard for SMS controllers, as well as smart controllers becoming mandatory in areas of the U.S. As identified in the Fifth Decennial NIS, it remains important to implement controllers on sites with the potential for irrigation reduction as well as proper implementation with the best current information. Finally, there is a need to understand human interaction with these devices because improper programming can make the difference between a water-saving device and ineffective technology with a dissatisfied customer. Keywords: ET controller, Landscape irrigation, Smart controller, SMS, Soil moisture sensor, Soil water sensor.

Selecting High-Impact Landscape Irrigation Conservation Behaviors: Formative Research to Inform Behavior-Change Efforts

“…Understanding the end users of irrigation technologies and practices is important to the ultimate success of a conservation initiative (Dukes, 2020). Successful social marketing campaigns rely on selecting discrete target behavior(s) and conducting audience research on the desired benefits and perceived barriers to those behaviors (Lee & Kotler, 2011; McKenzie-Mohr & Schultz, 2014).…”

“…Much remains to be understood about the application of social marketing to household water consumption (Lowe et al, 2015) and the lack of availability of such information can ultimately hinder interventions that positively impact water issues (Warner, 2019). Further, water conservation research on impactful practices can be costly (Nielson et al, 2021), and has largely focused on the technical strategies themselves without considering behavioral characteristics (Dukes, 2020), situating the "human element of landscape water management" (Mayer et al, 2015, p. 2) among the greatest research needs relative to outdoor water savings.…”

Beyond 2020, Vision of the Future: Selected Papers from the Sixth Decennial National Irrigation Symposium

“…Irrigation for turf and landscape is a major use of municipal water in the U.S. and continues to be scrutinized by water planners and regulators looking for additional ways to conserve water. Four journal articles in this Special Collection were related to turf and landscape irrigation, three concerning irrigation controllers (Cardenas et al, 2020;Conger and Dukes, 2020;Dukes, 2020), and the other article (Allen et al, 2020b) was previously discussed in the Evapotranspiration section.…”

“…A comprehensive review of smart irrigation controllers for turf and landscape irrigation was discussed by Dukes (2020). When irrigation savings were reported (12 of 17 studies), the average savings in research plots was 51%, but savings for residential systems averaged only 30%.…”

“…Advances in irrigation technology [e.g., sensors, irrigation controllers, unmanned aerial systems (UAS)] and its adoption and the availability of innovative research, extension, and education programs in irrigation science were key factors in the progress of irrigation management in the U.S. during the past decade. Seven journal articles from this ASABE Special Collection are discussed in this section, but ten additional articles (Andrade et al, 2020a(Andrade et al, , 2020bCardenas et al, 2020;Conger and Dukes, 2020;Dukes, 2020;Evett et al, 2020b;Lena et al, 2020;O'Shaughnessy et al, 2020;Stone et al, 2020;Sui et al, 2020) discussed in other sections of this article easily overlap with this topic.…”