Soil Sensor Overview
This article will cover the ins and outs with regard to Soil Sensors.
One of the most important concepts to understand with soil sensors is proper installation and accurate reporting of ONE sensor to manage an entire landscape.
A single sensor can be used to control the irrigation for many zones (where an irrigation zone is defined by a solenoid valve) OR multiple sensors can be used to irrigate individual zones. In the case of one sensor for several zones, the zone that is normally the driest, or most in need of irrigation, is selected for placement of the sensor in order to ensure adequate irrigation in all zones. Many lawns have multiple micro-climates that they need to account for; from south-facing and full sun to north-facing with a slope, a mesh network of sensors is the best approach for a true closed loop feedback of your lawn's health.
The Rachio unit can be setup with a wired soil sensor to achieve bypass scheduling.
Please keep in mind some general rules for the burial of the soil moisture sensors, which include:
- Bypass scheduling is similar to that of a rain sensor; it interrupts the common wire and prohibits the controller from watering.
- Soil in the area of burial should be representative of the entire irrigated area.
- Sensors should be buried in the root zone of the plants to be irrigated, because this is where plants will extract water. Burial in the root zone will help ensure adequate turf or landscape quality. For turf grass, the sensor should typically be buried at about three inches deep.
- Sensors need to be in good contact with the soil after burial; there should be no air gaps surrounding the sensor. Soil should be packed firmly but not excessively around the sensor.
- If one sensor is used to control the entire irrigation system, it should be buried in the zone that requires water first, to ensure that all zones get adequate irrigation. Typically, this will be an area with full sun or the area with the most sun exposure.
- Sensors should be placed at least 5 feet from the home, property line, or an impervious surface (such as a driveway) and 3 feet from a planted bed area.
- Sensors should also be located at least 5 feet from irrigation heads and toward the center of an irrigation zone.
- Sensors should not be buried in high traffic areas to prevent excess compaction of the soil around the sensor.