Moisture sensors are a good option for monitoring citrus irrigation, so you’ll want to make sure they are installed correctly.


Irrigating citrus is a necessity in The Sunshine State, and monitoring citrus irrigation is the best way to ensure that citrus growers are hitting the “sweet spot” of irrigation, leaving citrus neither too wet or too dry. A Citrus Industry article shared details on moisture sensors, including installing moisture sensors. See the details below.

Installing Moisture Sensors

These steps were taken word-for-word from the article for installing a TDT or TDR sensor:

  1. “Before installing a soil water sensor, select a suitable “sensor tree” in the grove that represents the average condition of the trees in the irrigation zone. Avoid very large or very small trees, and those that have major defects or disease symptoms. Consider the distance from the sensor to the nearest power source (e.g., pumphouse) or data logger location if the sensor system will require them. If wireless data communications will be used, consider the proximity to the nearest receiver station and the ability to mount an external antenna mast. If the soil sensor station will be solar-powered, then ensure that the solar panel faces south, away from the sensor tree, without excessive shading from surrounding trees.”
  2. “For citrus groves, two sensors installed at two depths in the irrigated soil under a tree canopy are adequate per location. The upper-level sensor can be installed in a vertical orientation by simply pushing the metal prong or loop body into soft sandy soil, until the plastic cable header is about level with the surface of the soil or leaf litter. Soil water will be measured along the metal body only, representing a depth interval of approximately 2 to 8 inches below the soil surface. The second sensor is installed horizontally at a depth of 18 inches, approximately below the upper sensor. The upper sensor will therefore measure the soil water in the critically important topsoil layer with the highest density of citrus roots. The lower sensor serves to check whether the upper layers are adequately filled with water, and also warns the user when excess irrigation or rainfall has occurred.”
  3. “A good installation of soil water sensors under citrus trees may require some experimenting, and with mature trees, some digging through roots! Tips and potential pitfalls are:
  • Avoid large roots and other buried objects like pipes that could cause air gaps and interference around the sensor body.
  • Avoid placing the sensors in any location where water from irrigation or rainfall will be concentrated or shielded (e.g., avoid the tree dripline and the base of the trunk, or low spots).
  • Avoid placing sensors too close to or too far from the irrigation emitters. About midway in the wetted pattern is a good position.
  • Try to replace and compact the soil back to where it came from during sensor installation because topsoil and subsoil have different water-holding capacities.”

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions or concerns about your farm or pasture, contact us and one of our team will be in touch.