Growing the same amount of lettuce on 20 m² as on 200 m² can be done by using growing towers. Dutch Lion developed a growing system for this purpose, which is currently being validated at the World Horti Center in Naaldwijk. Meanwhile, an anthurium grower is also getting acquainted with the system for propagation, and larger projects are in the pipeline.
Founder Vincent van der Gaag will give an update at the end of February. The Managing Director will do this the day before an official harvest celebration with guests, while taking a look at the striking cultivation system from above.
The system was devised for a greenhouse with a 7-meter leg height.
In Naaldwijk, the cultivation system was built last autumn. Cultivation of butterhead lettuce started in January. The aim is to continue growing various crops at the World Horti Center to validate the system and, meanwhile, show the market what is possible.
In the greenhouse compartment for the test is a construction with four monorails, each with 30 cultivation towers. Each tower now grows 42 heads of lettuce, but this can be expanded to 60, saving a grower a lot of space. "Ninety percent, to be precise," Vincent calculates for us.
The plants in the cultivation towers are watered via drippers
Hybrid
When introducing the system, Dutch Lion deliberately chose not to talk about "vertical farming." The market for vertical farming has gone through difficult times—and partly rightly so, says Vincent. Daylightless multilayer growing did not prove easy for many companies during the energy crisis. "Investments failed to materialize or were misspent, cultivation companies had to stop or went bankrupt—partly because unit economics are unprofitable due to high energy costs and complicated automation. Greenhouses use free daylight and technologies that have proven themselves for decades."
The trial is equipped with daylight LED. Dutch Lion is brand-independent for LED lighting.
Dutch Lion combines what works, he stresses. "We are now using all the advantages of vertical farming and all the advantages of growing in a greenhouse." Vincent already has a lot of operational experience with his distinctive cultivation system. Initially, it had been applied in a daylightless cultivation container, where the system was developed and extensively tested. Now it is time for the next step, and it will be deployed in a greenhouse.
For the trial, the cultivation towers were numbered with notes.
Mechanical
The system in the greenhouse still uses parts of the smart, mechanical carousel technology that Vincent previously used in cultivation containers. However, the several-meter-high cultivation towers no longer rotate. Instead, during cultivation, from sowing to harvest, they move forward.
The system is quite similar to a mobile gutter system for growing on water, where the gutters can also move apart, only in this case, they do so vertically. By automatically moving the towers apart, the heads of lettuce get more room to grow. "We start heart-to-heart with 8 centimeters of distance, and at the end of the growing cycle, it's 22 centimeters," he says. One cylinder at the front controls the entire monorail completely mechanically. "That reduces maintenance and keeps it as simple as possible."
The towers consist of plastic parts that can be linked, and can also be made horizontal.
Daylight and air movement
Anyone who starts growing vertically in a greenhouse can expect light loss for the lower heads of lettuce. In the trial, where PAR sensors will still be installed, they measure light levels, and the daylight LED lighting adjusts to the required light levels. "We need more light than in horizontal cultivation, but we recoup that with lower labor and heating costs because we are working on a much smaller cultivation area."
To maintain a good climate between the towers, vertical air movement is used. The technology for this works with air hoses for optimal air movement. "With this, we equalize the climate between below and above. With our system, we take care of the air distribution ourselves. The climate chamber takes care of creating the climate."
Air hoses with holes ensure air movement
Unit economics
The developments at Dutch Lion have already attracted the attention of an investor with experience in the vertical farming market. "We focus on unit economics with this system. That was still a stumbling block in traditional vertical farming projects. By being able to make the greenhouse 90% smaller, the project CAPEX is 40% lower compared to an automated greenhouse with our system. At the bottom line, this results in 20% lower crop costs than with a comparable horizontal growing system."
At Dutch Lion, they believe "100%" in the benefits of hybrid growing. Remarkably, several other parties in the horticultural sector have recently come forward with unconventional cultivation systems. All are trying to offer alternatives to well-known systems, focusing on labor savings and far-reaching automation, among other things.
A little further down the World Horti Center, for instance, Biomic Agritech's system is also running. Saia Agribotics, with a test greenhouse in Ede, chooses to move tomato plants to the processing area instead of moving people to the tomato plants. The overlap: the different parties all challenge the market, with different types of cultivation systems, to look at labor differently.
Below, water drips from the cultivation towers. Thanks to this way of growing on water, water use is low. "We found that we have up to 70% less watering compared to horizontal mobile guttering systems - which saves significantly on CAPEX and water consumption," Vincent (left beside the screen) shared with a group of invited guests on 6 March.
Indoor Ag-Con
Although currently only the production phase of the cultivation system is included in the setup, the whole cycle can be automated, from automated sowing, transport, and harvesting to automated cleaning of the towers. "The cycle is sacred," Vincent stresses. "Harvesting and re-sowing every day is important. That way, the crops grow optimally, 365 days a year." Short crops are preferred. "The longer the crop, the higher the cost of supplemental lighting," he says.
Dutch Lion targets new-build projects with the system, but it is also possible to install the system in existing greenhouses. The weight of the system is comparable to that of hanging gutters for tomato cultivation, for example, Vincent notes.
On March 11 and 12, Dutch Lion will be present at Indoor Ag-Con. The company can be found there at stand 725.
For more information:
Vincent van der Gaag
Dutch Lion
[email protected]
www.dutchlionag.tech