"The key advantage of vertical farms lies in their control and productivity. With multi-layer setups, the yield per cubic meter can significantly surpass that of conventional farming," says Maarten Ameye, Research Leader at Inagro.
"However, the energy demand is a drawback, as sunlight is no longer utilized. Addressing this energy challenge—through sources like industrial waste heat or renewable energy—is critical. We're optimistic that technological advancements will solve this within the coming years," he says.
Inagro conducts research for greenhouse and agricultural farming in Flanders. In 2020, they acquired their first vertical farm to assess its potential for agriculture, both regionally and across Europe.
The impact of far-red light
One of Inagro's current experiments involves testing the impact of far-red light to optimize lettuce growth. "Blue and red light are used by the plant mainly in photosynthesis and, together with water and CO2, leads to the production of the building materials for growth. In addition to this light, far-red light has a role in plant development. Plants use this light as a control light and the ratio of red to far-red light forms a signal in nature for the plant to know if it is in the shade of another plant. This signal can then lead to more growth (eventually getting more sunlight)," Maarten explains.
In previous research, Inagro saw that when they administer more artificial far-red light in MGS (mobile gutter system) hydroponics, it has a positive impact on crop diameter. "Now we are looking further into optimization. Vertical farms are ideal for such research because we can set the light recipes separately for each table. We now try to answer the question of when it is best to turn on this extra red light: is it continuous, only at the end of the light period, at the start of the night, and for how long during this period?"
More lighting research
In October, Inagro started the IE light project, using their vertical farm as the first screening phase. The project is led by KU Leuven. "We want to see if we can achieve energy savings by adapting our lighting strategies. We were inspired by nature, where the sun rises and sets gradually, and leaves are not continuously in the light, but there may be shadows. This led us to two lighting strategies where we will slowly turn on the lights at the beginning of the light period, and gradually dim them at the end.
The second strategy, however, consists of working with pulsed light. For this we will, for example, leave the light on for 9 seconds, and then dim it for 1 second. Here we are studying whether there is an effect on plant development in both different varieties of lettuce, and later in strawberries. However, it is also important to see if we are effectively achieving energy savings. After the screening phase in the vertical farm, we will apply this in hydroponic crops in greenhouses and see if we have similar results," he explains.
The potential of vertical farming
When it comes to vertical farming, Maarten sees significant potential for integrating them in urbanized environments to bring food production closer to the population, or in industrial zones where it is sometimes easier to link to other sources of energy. "Also, in industrial zones there is often still space available on the top layer of warehouses, companies, etc. that could be set up for primary production," he says. "In both cases we do believe that you have to start from the market that is there. Which crop grown in a vertical farm brings added value to that location and in which season? We must not lose sight of the fact that products from a vertical farm compete with crops grown in open fields, or in greenhouses, or with crops that are imported. Therefore, it must not only be good in terms of cultivation, but it must also be economically viable."
Besides those cases, Inagro thinks vertical farming can still play its role in today's horticulture. "Such systems can be a part of the cultivation strategy. Consider, for example, the propagation of planting material (e.g. leafy crops, strawberries, leeks). At present, people are sometimes dependent on planting material imported or purchased from other growers, where they are not always sure of the quality, where soil particles can still be affected by certain diseases or where there is less control over the use of pesticides. Vertical farms take up less space, making it accessible to growers to take propagation into their own hands. This vertical integration gives them control over cultivation from seed to product."
In Agrotopia, Inagro also researches the potential of hybrid systems. "The advantage of vertical farms is growing in several layers, and the advantage of traditional greenhouses is using light and heat from the sun. We want to combine these two advantages and arrive at an optimal system that makes maximum use of the available space." Inagro has installed three vertical farming towers in collaboration with Urban Crop Solutions. These consist of several rotating layers and are located inside a greenhouse. "In doing so, we thus maximize the ground surface but still get free energy from the sun. The first full-scale trials will start this year, where we will collect both cultivation and economic data. In Agrotopia, we will have different cultivation methods at our disposal (MGS, DFT, vertical farms, hybrid tower) and we will be able to compare them and see what added value each system has to offer. This way, we can give better advice at the Flemish and European level: what situation makes each system most suitable for growing crops?"
For more information:
Inagro
Ieperseweg 87
8800 Rumbeke-Beitem, Belgium
Tel: 051 27 32 00
[email protected]
www.inagro.be