Hydroponics is the growing method of choice in a modern Dutch greenhouse. The hydroponic system is based on the growing system by which water is provided to the plant while the plant does not grow in the full soil. The substrate or soilless culture is the most common in the greenhouse industry. Just a few decades ago, the greenhouses in the Westland area of the Netherlands where obligated to remove their crop out of the soil. The groundwater was getting polluted due to the intensified horticulture in the region that the ground water levels where contaminated to unacceptable levels. Though still within the most limits of most countries, the Dutch legislator had decided to remove the crop from the soil. In the early days it required some adjustments for the greenhouse growers, but in the end it appeared to be a blessing. The grower was now more in control than ever, the right minerals and the right amount of minerals where provided to the plants. This allowed for optimal control and improved yields.
Hanging gutters is a form of hydroponic cultivation. Long gutters are suspended from the greenhouse structure, utilizing the slope of the structure. Widely applied for vegetable crops, mats of mineral wool are placed on top of the gutters as hydroponic medium. The plants are hydrated through a drip irrigation system where excess water is collected by the gutter.
As a plant usually thrives on a little excess water, the irrigation will be more than required for the plant to consume. As the water now does not drain into the soil, it will be collected by the growing gutter and transported to a drain system. The excess water with the minerals is recollected into a drain holding tank, as this water has been throughout the greenhouse it is important to eradicate of all possible diseases.
Another widely applied form of hydroponics is the soilless cultivation on tables. The cultivation tables are commonly applied in potted plants, herbs, leafy greens and ornamental crops. The method of irrigation differs between ebb and flow and NFT.
In many cases drain water is treated by a UV sterilizer with enough energy to destroy the possible harmful bacteria and viruses. These micro-organisms will be destroyed by the energy of the UV Sterilizer. Applying the hydroponic growing method is in Dutch Greenhouses a must to minimize water consumption improve the production whilst giving the grower maximum control.