When cultivating spinach on water, growers with different systems face the issue of the crop 'poisoning' itself after a few cycles. The cause is suspected to be root exudates. The difficulty is that this has not yet been definitively established, and it is not yet certain which substance or substances exactly are causing the problem. This has led Industrial Product Solutions, together with its Indian partner Pinterra, to try tackling the problem through a new cultivation system.

"Because of the problems the market is facing, we started to look into vertical cultivation," says André van der Stoel, the CEO of Industrial Product Solutions. Together with Pinterra, the company has developed a demonstration setup for the vertical cultivation of spinach on water. "We have been testing this for a year now. It's a constantly running cultivation process where you harvest every day, although, for the test, we did it every week. We have been running the test for a year without any issues."

The 2 by 5 meter system has been operating in India. André was there last December to see it for himself. He was part of a Dutch trade mission. "While there, we signed a collaboration agreement with Pinterra to market this innovative cultivation system."


André (left) signs a collaboration agreement with Pinterra

No root exudates, but dissolved oxygen
The system (in the photo below) is operated manually, including the replacement of the substrate, which in this system is a membrane. "This membrane is made of cellulose. It's a sterile material. After each harvest, we replace the membrane. This also removes the roots and root exudates." During the one-year test period, it also became clear that it is possible to compost the membranes in the water. "Only roots remain at that point, after the harvest."

The next step the partners want to take is to fully automate the system. "This is not necessarily required, but it is essential for scaling up." It is also advisable to install a system to purify the water. "During the test, only a very simple unit was used. The use of dissolved oxygen was crucial. It was a very important addition to get the system working well."

2.0 version
In the test, the same water was used for a year. "We only added fertilizers. When scaling up, water disinfection is certainly recommended. It gives the grower even more certainty." The two parties are currently working on developing a 2.0 version of the system. This system will be fully automated. "It's a cultivation system where crops can be grown at a high density. Cultivation can take place at different densities during different cultivation stages. Changing the density happens fully automatically in an automated system."

Testing will also continue with the 1.0 system (see the photo below); "for example, with the composting of the membranes. I'm taking these membranes to Fruit Logistica in Berlin. There, I'd be happy to tell you more about the system. It's also great for growing a variety of smaller herb and lettuce varieties."

Industrial Product Solutions can be found at Fruit Logistica in hall 3.1, stand A-33.

For more information:
André van der Stoel
Gert-Jan Mulder
Industrial Product Solutions BV
André: +31 (0) 646713208
Gert-Jan: + 31 (0) 648122944
info@industrialproductsolutions.nl
www.industrialproductsolutions.nl