In the project “Prevention and Control of leaching from greenhouses”, solutions are developed to minimise leaching of nutrients and pesticides from greenhouses to the environment (especially surface water), in order to comply with legislation and societal demands. In 2017 the main results are as follows:
· To prevent emission, drain solutions are reused or purified. Other water flows may deviate in composition and possibilities for reuse or purification. The option for reuse or purification for these water flows has been investigated, and a working methodology for the end of a cultivation (e.g. cleaning) has been developed.
· Applications of Forward Osmosis in horticulture have been investigated. Water extracted from the discharge flow with Forward Osmosis using the concentrated nutrient solution holds prospects, but extracting irrigation water from brackish groundwater seems less feasible.
· In a long-term experiment, sodium (Na) standards for sweet pepper have been reinterpreted. It was shown that an increase in the Na standard up to 8-10 mmol/l causes no damage or loss in pepper production. In addition, it was shown that the split-root system can be used for uptake of extra Na without growth hampering. Furthermore, applying humate can prevent negative sodium effects at high sodium levels (Chinese cabbage).
· Finally, insight was gained into the risks associated with the use of chlorinated cleaning products in zero-discharge cultivations. Trials with gerbera show that higher concentrations may cause crop damage.
PARTNERS AND FINANCING
In this Public-Private cooperation, the Business Unit Greenhouse Horticulture of Wageningen University & Research works together with KWR Water, LTO Glaskracht NL, Haket, Yara, WaterQ, Verhoeve Milieu & Water, Priva, Blue-Tec, Humintech and Crop Cooperative Gerbera.
Financing: Topsector Horticulture & Starting Materials, TKI Water Technology, Stichting Programmafonds Glastuinbouw and the partners.
Click here to view the full report (in Dutch).
Photo credit: Wageningen University & Research