The watermark meter electronically measures the degree of dryness of the soil. The grower can use the measurements to determine whether or not to water. In recent years, much research has been done into the ideal moisture condition during the growing season. During the shoot growth phase, a certain degree of drought stress can be beneficial to inhibit shoot growth, without compromising fruit growth. With these watermark measurements, the grower can closely monitor the degree of drought stress and respond accordingly with watering.
These measurements have already proven their value in tree nurseries as well. Tree nursery crops should in principle never be under drought stress.
In fact, the watermark meter is an electronic variant of the tensiometer. The grower places the sensors in the soil and reads the measurements with a separate reading box. This gives the grower the freedom to place as many sensors as he wants.
The number of sensors depends on the type of soil. In general, two sensors are placed per measurement location. One at 30 cm and one at 60 cm depth. Six to eight measuring points per company are usually sufficient to get a good picture of the moisture condition. The readings are corrected based on the temperature of the humidity sensor. This temperature is set on the measuring box. Two thermometers are sufficient per company.
