Water collected beneath a greenhouse crop can still contain useful fertilizer. Knowing which nutrients remain, and which need topping up, is the problem a Danish–German research project is trying to solve.
Kiel University described the NutriCycle project in an October 19, 2026 update. The team plans to begin with nitrate measurement and add other nutrients later. [Kiel University](https://www.uni-kiel.de/en/university/details/news/zu-schade-fuer-den-abfluss-naehrstoffe-im-giesswasser)
The University of Southern Denmark is leading the three-year project, which has a budget of just over €1.8 million. Researchers plan to analyze small water samples using chemical reactions and optical sensors, then test a prototype at NPZ Innovation in Germany.
An overall salt reading does not tell a grower how much of each nutrient is in the water. More detailed measurements could help guide fertilizer additions while keeping usable water in circulation. The equipment is still being developed, so savings remain to be demonstrated in practice. [University of Southern Denmark](https://www.sdu.dk/en/om-sdu/fakulteterne/teknik/nyt_fra_det_tekniske_fakultet/ny-sensor-skal-skraeddersy-planternes-goedning-og-mindske-spildevandsudledning)
For a buyer planning a greenhouse with water reuse, this raises a useful question: which measurements will be available on site, and which will still need laboratory analysis?
Our recommendation is to discuss that alongside the irrigation layout. Ask the supplier to explain how drainage water will be collected and treated, and how its suitability for reuse will be checked. Include routine sampling and sensor maintenance in the operating plan.
Yutuo supplies glass, PE film and polycarbonate greenhouses, with irrigation and climate-control options configured for individual projects. To discuss a planned greenhouse, visit [Yutuo Greenhouse]
