At the end of November, Klaas Schenk brought in the last 3 ha of seed potatoes. The first year of the switch to cultivation on wide beds with drip irrigation went differently than expected. “The problem is that the machine has to come from abroad. There they grow 2 x 90 cm and here you are stuck at 2 x 75 cm. However, I consciously opted for 1.80 m, because then I can fit two dripping hoses per bed between three rows of potatoes. As a result, I lose less land to tracks and I realize more ground cover.”
No extra water needed
Afterwards, the arable farmer admits that he thought too lightly about the entire installation. Delivery problems and lack of knowledge of arable farming at the supplier caused many delays. What he managed to achieve is the installation of drip hoses (diameter 22 mm, discharge point every 30 cm) during planting (3 cm below the ground), the construction of the silo (900 cubic meters of water buffer) and the drilling to groundwater (on 21 m depth). In July, later than planned, the main pipe (diameter 125 mm, total length of 500 m) was laid in the ground and dripping hoses could be connected. An infiltration pipe for underground water storage has not yet been developed.
However, it turned out not to be necessary to provide the cultivation with water. Schenk: ”There was enough moisture all year round. We have deployed three Agrometius stations that register suction pressure at 30 cm and we have always stayed within the margins. When we came out, it was because it was too wet.” The grower rolled up the unused drip hoses again at the end of September.
System not finished yet
The collection of rainwater was not realized due to the increased costs of PVC. This is on the agenda for next spring. Then there must also be a plan for infiltrating to an underground storage,” said the grower who wants to make the system immediately suitable for collecting drainage water.
What Schenk has in mind is a composite, adjustable drainage in which the grower has more control over the moisture balance of the soil and is less dependent on the water board.
The plan has been incorporated into a project and is eligible for PPP funds. ”You can then, as it were, set two heights, whereby you either let it drain or keep it in the root zone. During cluster showers you can direct excess water to your own storage facility and during dry periods you bring in water.” Such projects relating to agricultural water management can count on government support.
Comparison Tests
Schenk opted for relatively expensive Netafim hoses, € 1,200 per hectare, on the assumption that he could reuse them and thus have less of a burden on the environment. Unfortunately this is not possible. ”When pulling out and immediately coiling the hoses, they snapped here and there. Damage was probably also caused by planting them in one pass during planting,” says the grower, who has also thought about solutions.
Next season he wants to try two options side by side. ”In one case we opt for a cheaper hose and go for single use using the same machines. Otherwise, we will insert the hoses after planting. When removing the hoses, we first place them on top and then roll them up from the head end.”
It is not quite as he envisioned it, but Schenk knows that there are still many developments in the field of watering. ”Once the reception, storage and main pipeline have been realised, the foundation is in place. We are also open to new systems, adapted reels, booms and robots, there is still a lot that can be done.”
Enough kilos
You don’t hear Schenk complaining about yield and quality. “The tubers are good, no scab or rhizoctonia; we have few problems with reading. I have 5% oversized and 81% good seed in the class 28-55. All in all, more tons of seed potatoes harvested per hectare, but also 20% more seed potatoes planted.”
Pour more by giving dosed water as needed. In addition, profit can be made from planting. ”The new machine places them more precisely at distance and depth, which is already an advantage.
I think that the simultaneous insertion of the drip hoses was disadvantageous, because the soil then has to be compacted more. When I put them in later, I keep the topsoil more loose. That is better for growth, especially in a year like this with cold and too much rain after planting.” The potatoes will be placed 12 and 15 cm below the ground again next year. Finally, the average kg yield can be increased if harvesting takes place under better conditions. Now, according to Schenk, a relatively large number of potatoes remained on the land in November.
Harvester not supplied
The seed potatoes would first be harvested on top and then loaded. Schenk had bought a harvesting machine for this, but it was not delivered, not on September 1, not on October 1 and then not at all. “The problem is that the machine has to come from abroad. There they grow 2 x 90 cm and here you are stuck at 2 x 75 cm. However, I consciously opted for 1.80 m, because then I can fit two dripping hoses per bed between three rows of potatoes. As a result, I lose less land on spores and I realize more ground cover.”
In mid-October a machine arrived from Germany that had to harvest the potatoes on top. The bunker harvester was borrowed from a colleague for scooping. The last 3 ha were loaded on 24 November under bad weather conditions.
Schenk is not discouraged. The machine will be there next year. Large enough to process the entire soil layer during harvesting and can then be used for loading into the box.
Machine from Germany
As an alternative, in mid-October, a machine came from Germany to harvest the potatoes on top. The bunker harvester was borrowed from a colleague for scooping. The last 3 (of the 8) ha were cleared at the end of November under bad weather conditions.
Schenk is not discouraged. The machine will be there next year. Large enough to process the entire soil layer when harvesting and can then be used for harvesting directly in the box.
Looking back, he calls the cultivation on beds of 1.80 m a success. Now that he is on the reading tape, he can see this. “The tubers are good, no scab or rhizoctonia; we have few problems with reading. I have 5% oversized and 81% good seed potatoes in the 28-55 class.” All in all, the seed potato grower has harvested more tons per ha. He has planted 20% more seed potatoes. “The machine places them better at a distance, which is an advantage.”
Drip hose not used
The drip irrigation has not been in operation. “Nature has done what I intended. It has been continuously humid, sometimes even too wet”, says Schenk. Soil moisture and suction pressure were monitored with Vantage Agrometius equipment. To provide water for the cultivation, Schenk had drilled for groundwater at 21 m and a silo of 900 cubic meters was ready.
A 500-metre supply pipe was connected to 11 km of dripping hose that he had already installed underground during planting. At the end of September, the drip hoses were removed unused. ”We have learned,” says Schenk. I am in favor of reuse, so I also chose more expensive Netafim hoses, but when we remove them like we did, they still damage. Next year we will set up various tests with this.”
As an arable farmer, Klaas Schenk specializes in the cultivation of certified high-quality seed potatoes. His focus is on that. This spring he announced that he wanted to get the most out of the crop with drip irrigation, ie 15 tubers per plant, not too coarse and not too small.
The combination with cultivation on wide beds would help to make this change of course profitable. He divided 12 ha into sections of 1 to 2 ha, with a soil composition that was as homogeneous as possible, in order to supply these with water separately. Cultivation on wide beds went well, but watering was not necessary this season. Nature did its job.
More data desirable
- From Wageningen UR, expert Jits Riepma supported Schenk in the preparation phase, but he was unable to supervise the grower due to a change of position. Schenk says that the first year would be devoted to collecting data for the growth and watering model. He installed three Vantage Agrometius stations (suction pressure, percentage of soil moisture and temperature) and also placed Farm 2021 sensors (suction pressure). However, the data of the latter was not read, because the account was not created correctly. Next year, he will use the same setup and will want to compare the data.
- The recommended watering is tailored to the soil composition. The starting point was to irrigate for two hours per section per day, with a release of 2.4 mm being achieved. But because no water was given this year, nature did its job, there are no data on the effect of watering on soil moisture per soil type. Let alone on the effect on tuber and crop development, although this is still difficult to determine.
New next year is the contribution of AguroTech. This provider will realize an automatic link with the WATBAL model. The WATBAL model stands for water balance and provides insight into the moisture balance by using crop evaporation, the groundwater level and weather forecasts.
