Using Multi-Sensor Soil Moisture Probes to Decide When and How Long to Run Drip Irrigation

Figure 1.  EasyAg multi-sensor probe with sensors (bottom) at 4, 8, and 12 inches. The PVC pipe (top) is the access tube (1.2 inch diameter) that houses the probe. The probe can be connected to a wireless datalogger and transmit the data to the farm office for its use or be made available on the Internet for it to be accessed by anyone.Several methods of irrigation scheduling are used by producers, including the feel method, calendar method, soil water balance method, and soil moisture measurement method. The latter two methods are superior and help avoid too much or too little irrigation, because they consider the water storage within the plant root zone. The soil moisture method commonly involves measuring soil moisture in the root zone and irrigating when the soil moisture falls below 33% or 50% depletion of available water capacity (water in soil that is available to the plant). This 6-page fact sheet was written by Sanjay Shukla and Nathan Holt, and published by the UF Department of Agricultural and Biological Engineering, July 2014.