Researcher Ton Baltissen of Wageningen University & Research Centre said: "It addresses the problems of plant quality, water use and labour. You can use it standing up and also automate harvesting, thanks to a machine that we have just finished making. Harvesting is no longer dependent on weather."
The system also allows planting densities 2.5-times higher than in open ground, while irrigation pipes supply only enough water and nutrients for the plants. Any run-off is captured in gutters underneath, where it can be recycled and analysed if required. Soil is also continually monitored for moisture, pH and EC levels.
Some 3,500sq m in the Crum tree nursery has already been planted up using the system, in the form of 70 gantries that are each 50m long. Around 35 species are being tested for their suitability.
"Some plants grow better than others, but overall growth is better and faster than in the soil," Baltissen said. "Anyone can build one. Apart from the harvesting machine, there's no special technology involved, just things that are already on the market."
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