Options in soil moisture sensors

The Toro Company

Advancements in technology have led to the development of soil sensors that gobeyond measuring moisture. Toro’s Turf Guard wireless soil monitoring system, forexample, uses a wireless soil sensor buried below the surface of the soil to report notonly live moisture data, but temperature and salinity data as well. It does so at two distinctlevels in the soil profile, allowing turf managers to view trends via the Web-basedinterface both over time and over depth. Field managers can use this information todetermine if practices such as irrigating or flushing salt buildup should be adjusted.

For smaller systems, Toro has also launched a “lighter-duty” soil sensor, called thePrecision Soil Sensor, using a number of the same technologies as Turf Guard. Thisproduct is wireless, doesn’t require any burying to install, and it works with nearly anyirrigation controller.

Left, The Turf Guard wireless soil monitoring system from Toro.
Right, Toro’s new Precision Soil Sensor.


Dynamax, Inc.

For field managers in search of a portable solution, Dynamax, Inc. produces theTH2O and the TH150 portable soil moisture probes for sports turf and golf coursemanagement applications. The probes provide fast and accurate soil moisturereadings that can be used to schedule irrigation and avoid drought stress. DynamaxTheta probe technology works well in all types of soils and artificial medias, and haslittle or no temperature or salinity effects. The Theta probe can provide consistentresults, even in dry conditions down to about 2 to 3 percent water.

Left, Dynamax, Inc.s TH150 portable soil moisture probe
Right, The TH20 portable soil moisture probe from Dynamax, Inc.


Irrometer Co., Inc.

Irrometer Co. offers a range of products designed to aid in soil moisture monitoring,including the WATERMARK Electronic Module (WEM). The WEM worksin conjunction with irrigation controllers to improve scheduling efficiency based onplant demand. The system prevents irrigation cycles when the soil moisture is wetterthan the adjustable set point.

The WATERMARK Meter is a hand-held device designed for reading WATERMARKsensors in the field. The digital readout displays the sensors’ soil moisturestatus in centibars or kilopascals of soil water tension. This value represents theenergy a plant’s root system uses to draw water from the soil: higher tension valuesindicate drier soil, lower tension values indicate wetter soil.

Left, Irrometer Co.’s 30-KTD-NL Watermark Meter.
Right, The Watermark Electronic Module (WEM)from Irrometer Co.