The Dutch greenhouse horticulture sector is working towards achieving (nearly) zero water, nutrients, and crop protection product emissions by 2027. It wants to optimize surface water quality.
However, reusing several water flows during cultivation, especially crop rotation, is still difficult. The Platform for Sustainable Greenhouse Horticulture wanted an overview of those and their environmental impact, says Margreet Schoenmakers on Glastuinbouw Waterproof.
That request was addressed within the Water-efficient cultivation on substrate (LWV 19.201) top sector project. It is part of the Glastuinbouw Waterproof program researching the last bottlenecks in substrate crop drain water recirculation.
The different water flows have been outlined, and it was attempted to quantify these as much as possible in general terms. The project also tried indicating a priority order for the impact of water flows that people can use as points of attention in maintenance.
Not all water flows are equally relevant for improving surface water quality in greenhouse horticulture areas. That comes down to the amount of water released and the frequency with which that happens. As well as the area where the water waste stream is released, the concentration of crop protection products and nutrients, and whether purifying the water before discharge is possible.
A brochure includes a table summarising how much water the different flows release.
Drainage water
Based on expert judgment, an estimate was made showing which water flows have the greatest environmental impact. That is used to show its priority regarding its ecological burden. This prioritization could guide grower compliance and education. The higher the issue's propriety, the greater the chance of improvement.
Tackling leaching caused by a surplus of irrigation (drainage water) in soil-bound crops seems most urgent. Getting leaks in substrate crops under control follows closely. Besides prioritization and an impact estimation, the pamphlet also provides guidance on several key solutions.
Source: Glastuinbouw Waterproof