Cooling of greenhouse floor leads to improved plant activity

Last summer, Marco Rijstenbil of Rijk Zwaan in Fijnaart noted that plant growth was inhibited by the heat of his concrete floor. Marco: "We saw that the floor in our convertible greenhouses was getting too hot during summer. During the night, the floor was trying to get rid of excess heat, leading to the crops being too hot at the base, and too cold at the top. This of course, inhibited growth.”

Ground temperature
So how can the ground temperature remain low? To tackle this problem, Marco contacted ErfGoed in Moerkapelle. Together, they cut the ErfGoed floor to size. The various layers were determined for the root cloth. The grower also started thinking about how to deal with the drainage water. Ultimately, Marco opted for a substrate with a base of lava stones containing a drainage system. The drainage water is discharged, purified and reused. The new floor now cools the plants from below.

Since the lava stones are absorbing the water just below the root sheet, the bottom remains moist. Because of the heat, that moisture evaporates and thus cools the greenhouse: resulting in the root temperature staying cool. Marco: "It’s hard to measure, but you feel it when you put your hand on the floor. Also, you can see the plant thriving.”

For this greenhouse floor was chosen a white root cloth. It reflects heat. Black retains heat.

The floor is being laid.

Underground basin
Rijk Zwaan also wanted to make use of rainwater for irrigation. Because a basin takes up a lot of space, an underground basin was chosen. Under the floor is now a pool of 150 cubic meters. Because it is dark, the water remains clean. In summer there is little rain, and the basin is supplemented with tap water. Incidentally, calcium is added to the rain water, as there isn’t sufficient calcium in rain water in order to grow optimally.

White root cloth
For this greenhouse floor a white root cloth was chosen. It reflects heat. Black retains heat. "Everything is possible with this floor," laughs Marco. "It really lives up to expectations."

More information:
ErfGoed
Hugo Paans
Bredeweg 59
2751 GH Moerkapelle
tel +31 (0) 79 593 38 00
h.paans@erfgoed.nl
www.erfgoed.com