REAL-TIME quality check of measurements of soil water status in the vadose zone

The in-situ monitoring of soil suction and water content is important for a range of applications from civil engineering (e.g. estimation of groundwater infiltration) to agriculture (e.g. optimization of irrigation). The efficiency of field monitoring systems has recently improved thanks to the development of sensors that continuously record soil water status data and remotely transmit them through the internet. These data are, however, accessed by users only on a periodic basis, which impedes a timely detection of sensor failures. To overcome this limitation, this paper describes a method for automatically assessing the quality of suction and water content measurements in the field. The method is based on a real time comparison between field data and a reference soil-water retention curve. A tolerance box is introduced around each field data point, defined by a pair of suction and water content measurements. If the tolerance box intersects the reference soil-water retention curve, the suction and water content sensors are assumed to work correctly. Conversely, if the tolerance box falls outside the reference soil-water retention curve, at least one of the two sensors may have failed. The proposed method has been validated against measurements from five different agricultural soils confirming the efficiency of the tool in evaluating the accuracy of field data.