Application of a Wireless Sensor Network for Multi-Depth Soil Moisture Monitoring at Farm Scale in New Zealand’s Hill Country

Hill country farms play a critical role in the New Zealand’s economy and precision agriculture solutions have been increasingly utilised to improve their profitability and resilience. Soil moisture, a spatially and temporally variable factor in pasture productivity, was monitored using Wireless Sensor Networks (WSN) technology deployed over a hill country farm in the North Island. Geographical Information System assisted spatial methodologies were applied to design a WSN-topography. The integration of spatially distributed sensors and multi-depth soil moisture measurements from various hillslope positions showed that root zone soil moisture was more homogenous as the mean soil moisture increased. Considerable differences were found in soil water profile response to significant rainfall events on steep, rolling and flat surfaces allowing us to construct a clearer picture of the topographical controls on the variability of soil moisture.