Getting more for less without soil

When Yafour Al Hameli welcomed us to a shed after opening a huge iron door in the middle of constantly running big exhaust fans, we felt we were entering a big factory. But inside, one sees tomatoes growing in plastic containers attached to small black pipes for irrigation, reminding you that it is a modern vegetable farm. Although the black stuff in the container looks like sand, Al Hameli said it is not sand but a mixture of several other substances. “ This is open hydroponics inside a greenhouse, an agriculture system without soil. It gives at least 30 per cent more productivity and saves up to 40 per cent of water [used for irrigation], compared to conventional agriculture ” Emirati farmer in Tharwaniya "This is open hydroponics inside a greenhouse, an agriculture system without soil. It gives at least 30 per cent more productivity and saves up to 40 per cent of water [used for irrigation], compared to conventional agriculture," said the Emirati farmer in Tharwaniya near Liwa in the Western Region of Abu Dhabi. He spoke to journalists during a media trip organised by the Abu Dhabi Farmers Service Centre (ADFSC) to his farm on Wednesday. Method Hydroponics is a method of growing plants using mineral nutrient solutions in water, without soil. Although hydroponic systems do not involve soil, they may involve a wide variety of growing media, such as perlite, gravel, peat, sand, rockwool and others. Most of the plant nutrients are supplied by the nutrient solution, rather than by the media in which the plants are grown. Al Hameli has used a mixture of perlite and peat as a medium instead of sand to grow tomatoes in his open hydroponics system. ADFSC is supporting the demonstration of hydroponics farms of two Emirati farmers in the Western Region, which grow vegetables such as tomato, capsicum and cucumber throughout the year, including summer. "This method will help the growers to produce vegetables in their modified greenhouses throughout the year," ADFSC officials said. Al Hameli used to harvest about three tonnes of cucumber from his 1,500 square metre open field farm. "But from the same area of hydroponics farm I harvested four tonnes of cucumber." He introduced the new system about a year ago. The ADFSC expects to produce more vegetables using hydroponics in Abu Dhabi farms, said Dr Robert Caudwell, technical development section manager at the centre. The UAE farms produce vegetables and fruit mostly during winter. Productivity goes down considerably during summer. The new system is expected to change that and may ensure the presence of local vegetables and fruit throughout the year. Al Hameli is using ground water from borewells for irrigation. He thinks that in a water-scarce region where ground water is constantly depleting, the new system can save huge amounts of water used on irrigation. "I used to use 30,000 to 40,000 gallons of water a day in the open fields. But the hydroponics farm needs a few hundred gallons of water a day." Irrigation When he grew vegetables in the open field he used to irrigate it for about three hours a day. "But in hydroponics, the duration of each irrigation is about three minutes — it may go up to three to five times a day, depending on the weather," Al Hameli said. His irrigation system includes a desalination plant too, which highlights the problem of growing salinity in ground water. "For cucumber, the salinity should be below 1,000 ppm [parts per million]. But for capsicum it can be up to 3,000 ppm," he explains. The comparatively less amount of water used for irrigation in open hydroponics farm is further recycled and used in the open field farm. "It is my own idea. I made a tank to collect the used water which is pumped to the open field farm," Al Hameli said. About the cost of setting up a hydroponics farm, he said it comes to about a hundred thousand dirhams. He said he received support from the Shaikh Khalifa Fund, a government initiative to support entrepreneurial initiatives of Emiratis. Closed farms reuse resource Liwa: Two Emirati farmers in the Western Region are setting up closed hydroponics farms which will save up to 60 to 80 per cent of water used for irrigation, compared to conventional agriculture. "This is a Spanish method," said Ali Bakheet Al Mazroui during a media trip to his farm. Since the hydroponics system does not involve soil, it involves a wide variety of growing media, such as perlite, gravel, peat, sand, rock wool and others. In the closed hydroponic systems under construction at Emiratis' farms, rock wool is the medium. In this system, most of the plant nutrients are supplied by the nutrient solution, rather than by the media in which the plants are grown. In the closed hydroponics system the same nutrient solution is re-circulated and the nutrient concentrations are monitored and adjusted accordingly. At Al Mazroui's and Yafour Al Hameli's farms in Liwa, the closed hydroponics systems are under construction. They said the water used for irrigation in this system will be fully recycled and reused. In the open hydroponics system, the irrigated water is collected and used in the open field farm, Al Hameli said. Although hydroponics is not an organic farming method, the chemicals used in it are minimal, the farmers said. "I am trying to minimise the chemicals used to switch over gradually to organic farming," Al Hameli said. Advantage of system -Open hydroponics system saves up to 40 per cent water compared to conventional system whereas the closed system saves 60 to 80 per cent water. -High productivity — cucumber productivity in soil — 4kg/plant, but in hydroponics it is up to 10 kg/plant -Less maintenance cost -Limited chemical usage -Easy to manage -Very good returns -More sustainable approach