Soil moisture - Watermark - MMM Tech Support

Watermark Sensors

✓ Robust, user-friendly sensor

✓ Maintenance free

✓ Frost-proof

✓ Buffered

Profile Probe

Watermark Profile Probes

✓ 3 or 4 sensors in 1 shaft

✓ For measuring multiple soil layers

✓ Monitoring over complete profile

✓ Various lengths available

The use of Watermark Granular Matrix Sensors is specifically recommended for situations with longer time lags between water applications, i.e. in situations with higher fluctuation of soil moisture, for example in cases like irrigation by irrigation machines or in crops which need some degree of water stress or which are generally cultivated at the drier end. Besides the read-out equipment by Irrometer, Watermark Sensors also can be easily incorporated in many other data collection systems.

Advantages

Watermark Sensors measure soil water potential between 0 and 239 Centibar (0-239 kPa), are maintenance free and frost proof, and are buffered against varying salt content (EC value) in soil solution. Interpretation of data is easy, since measurement result is valid for all soil types. Watermark Sensors are durable and low cost, offer an accurate measurement result and have been field approved since decades.

Working Principle

Watermark Sensors consist of two electrodes, which are embedded in a special granular matrix. The sensors are protected by a stainless steel cover. Surrounding soil and the granular matrix inside a Watermark Sensor come to an equilibrium of soil water potential. The granular matrix has a varying resistance to electrical power (AC), depending on it's moisture content. This resistance is converted by the readout meter into soil water potential (unit Centibar).

Typical Applications

Irrigation scheduling in vegetables, asparagus and softfruit, irrigated by an irrigation machine, irrigation scheduling in vineyards, fruit trees, hops, potatoes, sugar beet, arable agriculture and seed production. Use in golf, garden and landscape irrigation.