Water supply is of crucial importance for greenhouse horticulture. An adequate supply of fresh (irrigation) water has to be available – during dry periods as well – and the water needs to be clean and not contain too many salts. Commitments have moreover been made to significantly decrease discharges of plant protection products from greenhouse horticulture in the years ahead and, ultimately, to eliminate them altogether.
This project is part of a coherent programme which should result in an integrated and sustainable (irrigation) water provision: the securing of ‘good irrigation water’, reduction of the use of disinfectants, and zero emissions of nutrients and environmentally-alien substances. The cluster research programme, ‘Circular Water Provision for (Greenhouse) Horticulture’, consists of four projects:
- Water to the greenhouse: freshwater provision and well technology
- Water in the greenhouse: microbially ‘healthy’ irrigation water
- Water from the greenhouse: water treatment and reuse
- Operate: operating circular irrigation water systems
Within these four projects the supply, discharge and use of water on a scale beyond that of the individual horticulturalist are studied. In this way, a sharper focus can be placed on closing the watercycle, increasing the sector’s self-sufficiency, assuring efficient water use, matching (regional) water surpluses and shortages in time and place, and reusing water.
The ‘Operate’ project involves the development of systems to make collective irrigation water provision efficiently and remotely controllable.
There is a trend towards the collective provision of irrigation water and water treatment. These systems meet several objectives besides supply security, for example, limiting discharges and sometimes also preventing floods. Furthermore, the horticulturalists want to be unburdened by having the water provision operated through cooperatives, or outsourced to utility companies.
The objective is the development of methods to automatically coordinate the circular water flows with water supply and demand in a greenhouse horticulture complex. The system has to take into account both the current and the forecast long-term demand for water. The coordination must take place automatically and remotely, by means of smart interconnections of measurement systems, models and ICT facilities (HydroBusiness, Brabant Water).
A start has been made on setting up a model to manage subsurface water storage. The measurement and control system consists of operational decision-making rules for short-term management. Moreover, the ASR system must be regularly (e.g., once a month) subject to calculations using a prediction model to forecast whether the freshwater volume is sufficient over the long term.