Why are you watering at 4 a.m.? Or 8 p.m.? "Because that's how I always do it." That's sometimes the only answer growers have. Klep is trying to change this by allowing growers to rent moisture sensors that can be linked to a solar cell and a platform.

The latter is particularly important, says Wim Voogt. He is a commercial technician working with soft fruit and greenhouse vegetables and, therefore, visits many growers. "With insight into data, including anonymously-provided data from colleagues, growers are better equipped to make decisions."

Nol Jochems, Jan Koevoets, Steffie Geerts, and Wim Voogt with the SOSensor with a solar cell at Strawberry Day 2024.

The sensor concept has been on the market for a year and a half. This is the second winter in which growers have been gaining experience with the system. The solar cell powers the sensor, which has a 4G card. This allows the sensor to communicate with the platform. "The sensor takes measurements every five minutes, but in order to save network costs and energy, this data is sent only once an hour."

You stick the sensor into the substrate to allow it to take measurements

Too wet
For growers, using the SOSensor is a way to obtain extra insight into the moisture status of the substrate. The abbreviation SO refers to the proprietary substrate brand Substrate Optimum from Klep BV Trading Company. "We and the growers have observed that there is still a lot of potential for improvement between the last and first watering. It often happens that the substrate remains too wet, which costs oxygen at the root level and affects the quality of the roots."

The sensor is powered by a solar cell

In summer, Klep's advisors also observed that, during very warm days, the moisture content still dropped in the afternoon despite growers providing a lot of water. "The temperature significantly rises in the afternoon, causing more evaporation. There is no more light than in the morning, but the water supply is determined by light, so the substrate becomes drier from the beginning of the afternoon. By using the SOSensor, this can be closely monitored, and adjustments can be made when necessary."

48-hour display of the sensor's moisture measurements in the platform. Click here to see the full-sized version of the graph and a graph with temperature data.

For more information:
Wim Voogt
C.J. Klep B.V. Trading Company