SOIL MOISTURE SENSOR IRRIGATION CONTROLLERS AND RECLAIMED WATER; PART I: FIELD-PLOT STUDY

摘要

Most soil moisture sensor systems (SMSs) marketed for landscape irrigation respond to the dielectric permittivity of the soil. Compared to potable water (PW), reclaimed water (RW) may contain more salts, which can modify the dielectric permittivity of the soil and, hence, alter the readings of SMSs when measuring the soil water content. The main objectives of this experiment were to evaluate the functionality of four SMS brands and to quantify potential irrigation savings. Secondary objectives were to analyze the behavior consistency of three units within a brand to control irrigation, and to compare the brands. The experiment was carried out in Gainesville, Florida, under turfgrass plots irrigated with PW in 2009 and RW with an average salinity of 0.75 dS/m during 2010. Four SMS brands (Acclima, AquaSpy, Baseline, and Dynamax) were selected and compared to a treatment without sensor feedback (WOS). Even though replicates of AquaSpy were statistically different under both PW and RW, all SMSs tested applied significantly less water than WOS. Water savings ranged 46%- 78% under PW, and 45%- 68% under RW. Therefore, SMSs can be a useful tool for conserving water on turfgrass irrigated with either PW or RW.