Soil Water Content Sensor in the IoT Precision Agriculture

The use of Internet of Things systems may now represent a feasible and real strategy for monitoring soil water content in several engineering fields. Very recently, a low-cost and low-frequency system based on a novel capacitive soil water content measurement has been developed and it is herein presented, as a first application, as a feasible approach in the framework of sustainable precision agriculture. The paper focuses primarily on the capacitive properties of the sensitive element, which makes it possible to measure salinity and volumetric soil water content simultaneously. The system is therefore provided by a customized capacitive sensor and an AD5933 impedance converter integrated on the same PCB. Preliminary experimental results on sandy soils characterized by different water contents and conductivities sound rather promising, thus envisaging the possibility of overcoming the known limitations of low-cost sensors for in-situ measurements.