The horticulture industry is constantly looking to improve itself. With a view to sustainability, circular materials play a major role in this effort. Grow 22, an event hosted by Kekkilä-BVB, explored the ways to reach a higher degree of circularity in raw materials used in the industry – specifically when it comes to substrates, in order to replace peat.
The panel was hosted by Marck Hagen, Innovations Director at Kekkilä-BVB, and featured Chris Blok, project manager Greenhouse Horticulture with Wageningen University & Research, and Adriaan Lieftinck, co-founder and CEO of MEZT, a spin-off of Delft University. Both Chris and Adriaan have done a lot of research to close the loop in the agriculture sector.
Alternatives to peat
Asked about the biggest challenges in this regard, Chris says it’s “a bit of a two-fold challenge. One is to reduce the amount of peat to remain on speaking terms with society and the authorities. On the other hand, there’s the development of alternatives – they need to reach the level of the current peat products.”
He points out there are quite a few alternatives available, but none of them can replace peat on their own. “So it needs to be a blend, and the blend needs to have a quality matching that of peat. So that’s a challenge for the coming years.”
That’s the supply part – but there are also expectations to manage. “In itself, the volumes in the market could be sufficient to fill the gap,” Chris believes. “But some other things are also happening in society. For example, energy use results in the use of wood products, and that means the demand for wood products is slightly different than when we started with these prognoses.” The same applies to compost and organic waste materials, which used to be abundant in the market. “But now more and more applications are found for these materials, such as producing fertilizers. So the market is moving at a rapid pace, and prices are changing.” As a result, the quantities available are also changing.
So how can the growing media industry compete with the energy market? Chris believes it’s still possible. “The amount of money the energy market can spend on raw materials is limited – provided gas prices return to normal levels.” Taking a longer-term perspective, he says the authorities should be reminded that it’s important for organic matter to return to arable soil. “If you burn it, you’ll lose the organic matter for arable soil, which will in itself create large problems.”
Another issue, where Adriaan and his company can play a part, is to rely less on fossil materials. He says technological innovation is important in achieving this goal. “Looking at history, most challenges have been solved by technical innovation, so that gives us some hope. When we were confronted with the nitrogen crisis in the Netherlands a few years ago, we thought that it might be possible to solve it without using the solution politicians put forward: they want to buy out farmers and reduce the amount of livestock in the Netherlands by 50 percent because we need to reduce nitrogen emissions by 50 percent.”
At MEZT, they thought: what if it’s possible to use technology to reduce emissions by 50 percent, without having to eliminate half of the industry? “The solution we have in hand provides the opportunity to reuse the minerals that are already present in farms, process them a bit, and reuse them as fertilizers. If we continue along that route, we significantly reduce the need for fossil fertilizers. That’s the route toward sustainable farming in the future.”
The million-dollar question is if we can reuse those organic components and use them in fertilizers for the greenhouse. Chris is optimistic. “The advantage of greenhouse horticulture is that the fertilizer costs are only 0.5 to perhaps 1 percent of the total turnover of a grower. In arable farming, 30 to 35 percent of a farmer’s income is used for fertilizers. So a slight increase in price makes it really difficult for arable growers to get those fertilizers, but in greenhouse horticulture that is not a big problem, as long as it delivers the right quality.”
Micro market for minerals
When can we expect this future to arrive? Already now, Adriaan sees companies interested in buying mineral concentrates from farmers who derive them from manure. “We foresee a micro-level market where any farmer who has a surplus or shortage of any mineral will be able to trade that on a market that will emerge in the near future. And that’s not only farmers – it can be greenhouse growers or other parties as well.”
Life after substrate
The front of the mineral supply chain is already looking good, but what happens to substrates after they’ve been used? Chris and his team are doing research there as well, and results have shown that fertilizers used for mushrooms can be reused to give mushrooms a boost against fungal diseases. “So there are opportunities, but it will take some time to be developed into a solid product.”
The fact that MEZT technology can selectively extract ammonium, potassium and phosphate will be very useful here, Adriaan explains. “We can recombine them in the exact, correct ratios, taking into account the crop, the soil and the season.” This can be useful not only for manure-based fertilizers, but also in the greenhouse industry, to put together base dressings.
Chris believes that in the future, the new technology will lead to a much more precise use of the right microbes in biostimulants. Adriaan goes a step further: “You not only need to bring in microbes, you also need to give the nutrients to that microbe, so that you really have the right colonies in the future. And I also expect that animal-based fertilizers can have a great effect on that.” While this is still a theoretical notion, it offers an exciting vision for the future.
To help make this work, regulations need to be updated urgently, says Adriaan. “The idea that whatever comes out of a cow is manure, is very limited. Even if you take out the unwanted substances, it’s still manure according to the rules. So we have to make sure our regulation keeps up with the technical possibilities. That’s something we all need to contribute to – convincing the regulators.”