The Wetting Front Detector (WFD) is a new tool to help measure how deeply water has penetrated into the soil after an irrigation event. The WFD also captures and stores a soil water sample, which can be analysed for its salt or nutrient content. The first commercial version of the Wetting Front Detector (WFD), called the FullStop, was released in 2004. The FullStop WFD is comprised of a