25 Jan, 2022

Increasing scarcity of water for greenhouse horticulture: what are the alternatives?

In all parts of the world, the availability of good irrigation water for horticulture is becoming a bigger problem. Internationally, an important factor is climate change; nationally – as in the Netherlands – another issue is the fall in groundwater levels. Research studies to find alternative sources of sustainable irrigation water are already taking place at the sector level in the Netherlands. Growers with questions can turn to Van der Ende Groep for solutions.

In the still quite recent past, growers in the Netherlands could rely on rainfall. After treatment, rainwater could be used as an excellent primary source of irrigation water. However, since the beginning of the century we have clearly seen a change in rainfall patterns. Periods of drought – defined as at least 20 consecutive days without measurable precipitation – are occurring more often in this country. In fact, 2018 and 2020 went into the books as the driest years since records began.

Availability under threat

This year started with minimal rainfall, combined with high temperatures; and we can all remember 2018: the KNMI (Royal Netherlands Meteorological Institute) recorded a record drought that year, from July until the autumn. At other times, the rain still comes down in the proverbial buckets. As a result, the quantity over a year might be similar, but at certain times of year the availability of intake water is under threat.

Alternative water sources for greenhouse horticulture

Growers are therefore seeking a solution in high recovery rates, and are also looking for alternative water sources. These exist, but they always have advantages and disadvantages. A frequently used alternative is borehole water. There are also water companies that raise the quality of surface water to a higher level, while in other regions the river water and other surface water are ‘clean’ enough to serve as intake water. And water for greenhouse horticulture is also increasingly sourced from the manufacturing industry or even power stations.

Water treatment with highly efficient reverse osmosis

These are all alternative sources, but none of them provide water that can be used immediately for irrigating crops. They need at least to be treated with reverse osmosis, for which Van der Ende Groep has developed the Nexus High Performance RO (HPRO). This makes it possible to remove ballast substances, such as salts, from the water, ready for ‘flavouring’ as required. Nearly all the unwanted elements have then been removed. An important advantage is that the system is extremely efficient, a plus point that becomes even more beneficial at times of high energy costs. With a recovery rate of up to 95 percent, the Nexus HPRO scores the maximum in terms of price-performance ratio per cubic metre.


While reverse osmosis is used for creating good irrigation water, the Kathari ultrafiltration system developed by Van der Ende Groep allows efficient recirculation of the water: efficient in the high removal rate for viruses, bacteria and fungi, and efficient in the area of costs, thanks to low operating and investment costs. And to avoid wasting any water due to excessive sodium content, growers can also use a sodium extractor. By employing a range of different water strategies, the continuity of the irrigation water supply is assured.

Choose continuity

If you too would like to safeguard the future of your water supply, simply contact us for the best solution for your situation.

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