General
Shallow sensors are generally installed by digging a trench using a 3” or 4” trenching shovel. Deeper sensors are installed down a 4” diameter hole dug with a hand auger. Sensors must be located where they will be wet by irrigation. The sensor reports average soil moisture along its active length - approximately 12”. Under most conditions, the sensor’s active range extends about 2” out from the sensor element.

Vineyards and Tree Crops
Install sensors in the vine row 1’ from a healthy vine, and in the tree row 1’ to 3’ from the tree. Sensors must be installed in an area that will be wet by the irrigation system. Roots damaged during installation will normally regrow within 30 days and maintain accurate soil moisture readings. Two or three sensors are generally used at each site and are placed at a 1’ depth and another at a 3’ depth. The shallow sensor is normally installed in the 3” or 4” trench and the deeper sensor in the augured hole.

Row Crops
In deeper rooted row crops, generally two sensors are used: one placed in the most active zone - 4” to 8” deep under/above a drip emitter in the row. The second sensor is placed at a depth 1/3 the distance from the bottom of the anticipated root growth depth. In shallow rooted crops, one sensor placed in the most active root zone is all that is required. The shallow sensor is generally placed horizontally.

Drip Irrigation Emitters
Locate the sensors directly under the drip emitter, or between the drip emitter and the plant.

Sprinklers
Install the sensors 1/3 to 1/2 the distance from the sprinkler to the edge of the wetter area. Locate the sensor in an area that gets a uniform water application. The sensor must be located in the active root zone of the crop.

Depth of Sensors
Two or three sensors are recommended for each monitoring site. One or two sensors can be located near the surface for monitoring crop use and one located deeper to monitor deep percolation of water. Monitoring the top zone is most important. For shallow rooted crops, location for the two top sensors will be the first sensor placed at 4” to 6” and the other at 12”. The third sensor is placed at 20” to 24” and is used to regulate the quantity of irrigation. For most crops, one sensor is located in the active root zone about 12” deep and a second sensor in the bottom 1/3 of the root zone, generally 24” to 36” deep. NOTE: A minimum of 3” of soil covering the sensor is required for accurate readings and the soil must be in direct contact with the sensor rods.

Sensor Orientation
It is recommended to install the shallow or top sensor in a horizontal position and sensors deeper than 18” should be installed vertically. Horizontal installation allows the soil to be easily packed around the elements for a precise measurement and will measure in an area about 2” above and below the sensor. The sensor will report average soil moisture over its entire active length of 12”. The roots must cover the entire length of the sensor in a vertical installation to ensure an accurate reading.

Sensor Cables
The sensor cable is suitable for direct burial or exposure to direct sunlight. It is recommended that the cable be installed in 3/4” electrical conduit to prevent mechanical damage.