Irrigation Savings from Smart Irrigation Technologies and a Smartphone App on Turfgrass

Abstract

HighlightsAll tested smart irrigation technologies regulated irrigation based on real-time soil moisture and weather conditions.Treatments based on SMS, ET, or smartphone app applied less water than the comparison treatment by 51% to 63%, 28% to 66%, and 51% to 63%, respectively.The payback period for the different technologies ranged between 0 and 12 months.Abstract. A plot study comparing a variety of irrigation scheduling technologies was conducted in Gainesville, Florida, from 2015 to 2017. Our study objectives were to: (1) compare the ability of different irrigation scheduling technologies to bypass scheduled irrigation cycles and/or decrease water application; and (2) compare water savings. Twelve irrigation scheduling treatments were investigated, with each replicated three or four times. Treatments included time-based schedules without sensor feedback (WOS), with a rain sensor, deficit irrigation with a rain sensor, and non-irrigated. Also included were three soil moisture sensor (SMS) based treatments, three weather or ET-based treatments (ET), and two smartphone app-based treatments. Significant differences in turfgrass quality among all treatments (including non-irrigated) were not observed during the testing periods, which tended to be wetter than normal. Compared to WOS, the SMS, ET, and smartphone app treatments achieved water savings of 51% to 63%, 28% to 66%, and 51% to 63%, respectively, depending on treatment specifics. Inclusion of additional practices, such as a split irrigation strategy (half in the morning and half in the evening) and seasonal deficit irrigation, were shown to be advantageous in an area where rainfall is frequent and a substantial contributor to plant water needs. The SMS treatments saved water by bypassing scheduled irrigation cycles, the ET controllers saved water mainly through lower application depths, while the app-based treatments saved water through a combination of bypassing and applying lower irrigation depths. The payback period for the evaluated scheduling technologies ranged between 0 and 12 months. Financial and practical considerations should be included when recommending or acquiring one of these irrigation scheduling technologies. Keywords: Evapotranspiration controllers, Smart irrigation controllers, Smartphone apps, Soil moisture sensors.