Feasibility study of the construction and evaluation of a soil moisture sensor in different soil textures

Real-time irrigation management considering field condition, has an important role on water saving and stability of agricultural and horticultural production. One of the approaches of real time irrigation management is the use of soil moisture sensors that have important effect on improving water productivity. In this study the feasibility of designing and evaluation of Iranian soil moisture accompanying watermark sensor was investigated in different soil textures. For designing and calibrating of Iranian soil moisture sensor, an experiment was conducted in 2018 and 2019 at Soil and Water Department of Yazd Agricultural and Natural Resources Research and Education Center. The designed sensor was evaluated in three different soil textures including sandy clay loam, loamy and silty clay with 4 replications. The designed and watermark sensors were calibrated in three soil textures, compared and validated with the direct method of soil moisture measurement. Results showed that the designed and watermark sensor could estimate soil moisture in loamy and sandy clay loam soil textures with proper precision. While in silty clay soil texture both designed and watermark sensors couldn't estimate the soil water content with acceptable precision. According to the results of this study, for soil water content lower than 50%AW(50% of available water), the designed and watermark sensors could accurately estimate the soil moisture. While for the soil water content upper than field capacity these sensors couldn’t acceptably estimate soil moisture.