Applications of wireless sensor networks, soil water balance modeling, and satellite data for crop evapotranspiration monitoring and irrigation management support

Irrigation scheduling systems can potentially be improved through the combined use of satellite driven estimates of crop evapotranspiration and real-time soil moisture data from wireless sensor networks. In order to analyze spatial and temporal patterns in soil moisture and evapotranspiration, we used wireless sensor networks deployed in operational agricultural fields across California to track evapotranspiration and soil moisture, and compute daily water budgets for multiple crops at the field scale. We present findings on efficacy and feasibility of using wireless sensor networks in an operational agricultural setting to monitor soil moisture and calculate a soil water balance. We compare estimated evapotranspiration rates from the wireless sensor networks against estimates from surface renewal instrumentation and satellite-derived estimates from the NASA Terrestrial Observation and Prediction System. Information from this research can lead to a better understanding of how to effectively monitor soil moisture levels at the field scale, and how to integrate satellite and sensor network data to support agricultural producers in optimizing irrigation scheduling.