Soil moisture content detection based on sensor networks

Abstract

With rapidly development of wireless communications and electronics, precision agriculture turns into a promising application of the sensor networks. In this paper, the measurement of volumetric moisture content for soil is explored with the sensor networks. The method of high-frequency capacitance is applied to the moisture content detection for three kinds of arable soil: red soil, moisture soil and paddy soil. First of all, the measuring principle is analyzed: high-frequency equivalent electronic model of soil test plate is serially connected with constant inductor, so as to obtain the relation between the equivalent capacitance and resonance. Then we measure the correspondence between resonance frequency and soil volumetric moisture content through experimental methods, in addition, the impact of resonance frequency range and environmental temperature is analyzed. To the best of our knowledge, this is the first study on soil moisture content detection based on high-frequency capacitance covering circuit theory, hardware simulation, resonance-frequency selection, temperature compensation and sensor networks. The experimental results validate the effectiveness of our method, thus, our method possesses significant application value.