Crop farmer Dirk Jan Beuling discovered the added value of soil moisture sensors when he took part in a project of the water board. He has high expectations of the future developments and applications of sensors in his business.
“I think the accumulation of all the information I gather in this way is important to optimise the result.“
“There it is,“ points out Dirk Jan Beuling. We walk across one of the potato fields of his business in First Exloërmond. The yellow rain gauge and solar panel stick up above the foliage of the potato plants. They are connected with a cable to the actual soil moisture sensors, which reach half a meter below ground level in a tube. “The sensors are at a depth of 20, 30, 40 and 50 centimetres,“ explains Beuling. “The information from the sensor goes via the Dacom supplier in Emmen automatically to the internet, so that I can see the soil moisture.“
In addition to starch potatoes, Beuling grows seed onions, barley and winter wheat, and sugar beets. He and his wife, with whom he has a professional partnership, took over the business from his parents in 1998. His own land comprises 180 hectares, and he also rents an extra 20 to 40 hectares every year. This year he has a total of 220 hectares. Beuling was introduced to sensor technology when he took part in the WaterSense project, organised by the water board and the Province of Drenthe. “In that project the sensors were used to investigate how well the water provision was functioning. Those sensors proved to be an excellent tool for identifying when the crop was becoming too dry, even before the plants were showing this.“
Beuling has now bought two Dacom TerraSen Station PRO soil moisture stations. Beuling shows on his computer what the sensors are measuring in the field. A chart shows the soil moisture level in the ground, with the precipitation above it. “It shows very well how the crop extracts moisture from the soil.“ The chart clearly shows how the line levels out during the night, and how moisture is replenished after a rain shower; the soil can even become too wet.
“This helps me decide whether it's time to start irrigating. Of course the weather forecast, the crop and the time of the season are also important. And irrigating has to fit into the work schedule.“
In the spring, Beuling uses the sensors for the wheat and potato crops first. “They need much more water in the spring than later in the year. I always say that in the spring a factory has to be built first, before the grain or potato can be filled. In August the days start to get shorter, and the crop is not growing so fast any more. For the onions I often cross out the depth of 40 and 50 centimeters, as the roots don't go as deep as that.“
Still a long way to go
Beuling keeps a keen eye on the development of sensor technology and precision farming. This year he asked Agrometius to scan a number of fields for pH and organic matter levels. “That scan shows the variation in pH and organic matter in the field, and on the basis of this the calcium variable is added. Nothing is added in places where there's enough calcium, and a lot is added where there's very little calcium. You might think this means you end up adding less calcium, but this is not the case. In a field of 14 hectares, with an average pH of 5.2, the contractor applied 35 tons of calcium in specific places. I wouldn't normally have applied any calcium when the average is 5.2, as I would have thought that with that average the field was fine. By adding calcium in specific places, the pH level becomes more even, and the absorption of other nutrients and spores should also be more even.“
Beuling feels certain he will make more use of sensors in the future. “I think that the accumulation of all the information I will collect over the years will be an important tool for optimising the result. We still have a long way to go, but when I compare these kinds of scans of the pH and organic matter, and also of the yield, I hope to discover patterns that can help me improve. Of course this has to be done digitally, because when I put the printouts side by side I no longer see the wood for the trees.
Agrifirm will probably start up a project to do so.“ “It would be ideal if I could send my employee with a job card in the machine to the field, so that variations in the field are automatically taken into account. This could be used when applying fertiliser, calcium, protection products, or anything else. It could also be used for water, as a higher organic matter level requires less water. Or for variations in plant density: the sandier the soil, the more densely the plants can be planted.
It pays for itself
Back to the soil moisture sensors. “I guess you want to know if using the sensors increases my income?“ asks Beuling. “I don't have any hard evidence, but this is how I see it: I've got two sprinkling systems, a pivot and a reel. They are driven by diesel motors, so irrigating incurs high costs. I therefore want to be sure whether or not I should use the sprinklers. The sensors help me make the right decision.“ Nevertheless, Beuling questions whether he can recover the costs of such investments in sensors and scans.
“The pH scan cost 350 euro per hectare. I have to grow 10 tons of beets to recover that. I don't have to do that in one year, but the question is: will I recover the investment costs? That is crucial to the question of whether or not the sensors will be a success. All I can say at the moment is that I believe they will. It's my intention to have a scan done for the pH and organic matter levels in my sugar beet fields in the years to come. Those fields rotate each year, and a quarter has sugar beets, so it takes four years to do them all. It will be interesting to see if the scans after four years show the same deficits as the current ones. But if I'm short of funds, an innovation like that will of course come under pressure.“