Effect of Temperature and Salinity on the Precision and Accuracy of Landscape Irrigation Soil Moisture Sensor Systems

Abstract

It has been demonstrated that soil moisture sensor systems (SMSs) designed for landscape irrigation can save water. However, SMSs have not been tested with reclaimed wastewater. Both salts contained in the irrigation water and temperature might alter the soil water content (SWC) sensed by SMSs. The objective of this research was to quantify the effect of salinity and/or temperature on the precision and accuracy of three different commercially available SMSs. The brands, controllers, and probes selected for this experiment were as follows: Acclima, SCX, and Digital TDT, Baseline, WaterTec S100, and biSensor, and Dynamax, IL200-MC, and SM200. Every SMS was replicated three times. Each SMS probe was installed in the center of different containers filled with an Arredondo fine sand. The containers were placed in a controlled-temperature chamber and were saturated and dried down across a combination of three temperatures (10, 25, or 35°C) and three electrical conductivities (0, 0.7, or