New greenhouse design: UAE farmers benefit from 90% water reduction
A greenhouse using water evaporated from plants to cool the crops could lead to farmers using 90% less of the precious resource.
Unveiled by Dubai’s International Centre for Biosaline Agriculture, the system would mean enormous savings for a country in which 56% of water used goes on agriculture. The greenhouse, being built on a farm in Al Dhaid, has been designed by a team of local and international scientists.
“Ninety per cent of the water we give to the plants is absorbed by the roots and transpired in the form of vapour,” said Dr Redouane Choukr-Allah, head of the project at ICBA. “It serves as a way of reducing the temperature of the plant otherwise it will get burnt, like when people sweat to cool down. So what we are planning on doing is recover that water and re-use it.”
The project is a collaboration between the ICBA, the Food and Agriculture Organisation, the Ministry of Environment and Water, and the International Centre for Agricultural Research in the Dry Areas, or Icarda. The greenhouse is due to be completed next month and operational in November.
It prompted great interest from Mohammed Sulaiman, a farmer of 30 years, who uses 1.9 million litres of water each day to cool his 500 greenhouses. “I am interested in what’s new and if there is anything we can learn about water,” Sulaiman said. “Any new technologies can help us to profit.
“We live in a very hot area so I only grow my vegetables 10 months a year when the weather is cooler, to avoid wasting so much groundwater,” he added.
The scientists say that, apart from the amount of water saved, the system would produce five times more food than could be grown in open fields. A desiccant, such as magnesium chloride, is used to reduce the humidity during the day, allowing the plants to transpire more water.
“At night, we heat up the desiccant to bring that water back to the greenhouse through evaporation,” Dr Choukr-Allah said. “The water will then condensate on the plastic of the greenhouse and go back down to the roots of the plants.”
“This type of protected agriculture will help save the UAE a copious amount of water and energy, while producing five times more food than in open fields.”
Dr Ahmed Moustafa, Icarda’s regional coordinator for the Arabian Peninsula, said the system was “essential for GCC countries and many dry areas”.
Experts from the FAO, Icarda and ICBA started drafting a 10-chapter paper in February to document new technologies in greenhouse cultivation that could cut down water use.
“It will tackle the vision for the future of agriculture in the GCC, the outlook of protected agriculture in the GCC and the new generation of greenhouses, as well as prospects of agricultural development in the GCC,” said Dr Wilfred Baudouin, a senior officer at the FAO. “It will end with recommendations for public and private-sector decision-makers.”