An efficient irrigation system should meet the demands of crops and minimize the amount of water applied. To investigate water use efficiency, on-The-go sensing technology (in this case, field elevation and apparent electrical conductivity) was used to reveal soil spatial variability relevant to water-holding capacity and to identify strategic sites where water availability could be monitored during the growing season to better determine plant needs. Nine locations in a 37-ha agricultural field were selected for monitoring the soil matric potential and temperature at four depths (18, 48, 79, and 109 cm) using wireless technology. These locations represented different growing conditions. The measurements were used to quantify the temporal variability of soil water content and water depletion, and to assess if the optimization of the irrigation water supply could increase water use efficiency in comparison to the current practice of uniform irrigation scheduling.