Water management
In addition to light and heat, water is of the greatest importance for the good growth of tomatoes and, naturally, many other crops inside and outside a greenhouse. The good management of the available water for the crop is, therefore, very important. Water is also the resource in which we administer the fertilisers that the plant needs. Every plant has its own drip that makes the water available to the plants gradually. The water with the fertilisers is transported to the drips through the water system, the substrate area in the professional jargon.
Per hectare (10,000 m2), between 15,000 to 20,000 m3 of water (which is 15,000,000 to 20,000,000 litres) is needed for the crop on an annual basis. If the water supplied by the water irrigation system is not absorbed completely by the plant, part is stored in the substrate mats and, if they are saturated, the water will leak into the recirculation gutters. This means that the surplus water that is given is caught and is taken to the dirty water silo. The water will go through a UV filter from this silo to deal with vegetable and other contaminations. The purified recirculation water will then go to the clean water silo. This water can again be used for new irrigation in the greenhouse. What is great about this system is that all fertilisers are retained because of the recirculation.
Discharging
The company does not have to discharge, in principle, any water that is used for the crop because of the recirculation system. This is only necessary when the recirculation water is too saline because salt is not absorbed by the tomato plants. If the quantity of salt in the water becomes too high, this will be discharged by the company to the sewer system.