Skye Instruments Limited.

Dial Tensiometers

The Dial Tensiometer is a low cost version of Skye’s successful field tensiometer range. Tensiometers measure the water availability to plant roots, and so can be used in irrigation scheduling and crop management.

Tensiometers are designed to be permanently installed in the growing medium, which they equilibrate with and measure the ‘soil suction’. Plant roots need to exert a suction to remove water from the soil, it is this suction which is measured by the tensiometers.

The tensiometer itself consists of a shaft of clear acrylic plastic (length variable depending on depth of measurement required), with a porous ceramic bulb at the lower end.

The top is sealed with a rubber stopper, and fitted with a dial pressure gauge.

This shaft is totally filled with water before installation into the growing medium to be measured. The water is able to flow in or out of the tensiometer via the ceramic bulb, as the suction inside the instrument equilibrates with the soil suction. The suction (or negative pressure) is shown directly on the gauge dial fitted into the top.

A series of tensiometers throughout the crop can give an accurate representation of crop water requirements and also produce a soil moisture map