With searing temperatures and little rainfall, the UAE offers a challenging environment for agriculture – but an Emirati man has developed a system that offers high yields while minimising water use.
Mohamed Al Nuaimi has been granted a US patent for his cutting-edge design, which combines the growing of crops with the rearing of fish, and recycles water, waste and nutrients.
The set-up created by the Sharjah native is optimised through multiple sensors and artificial intelligence-based monitoring, and needs only 10 to 20 per cent as much water as traditional farming.
It is described by him as an agroponic system, being an advanced, computer-controlled form of aquaponics, which combines aquaculture, where fish or other aquatic organisms are reared, with hydroponics, in which plants are grown without soil.
While the design has been developed and refined in the UAE, Mr Al Nuaimi thinks that it could be used in other arid parts of the world, such as Arizona in the US.
Why is the system significant?
Beginning as a hand-drawn sketch, the scheme has been running as a pilot project for five years, yielding a wide variety of crops, including basmati rice, which Mr Al Nuaimi is particularly happy about, as it requires climatic conditions different to those of the UAE.
“I’m very pleased with the outcome of the project and I’m very pleased that it’s been granted an agricultural patent,” he told The National.
“The agroponic system is adaptable in different regions and it saves, as an example, the requirement of crop rotation, so it’s better for land management. You’re not depleting anything from the soil since it’s all an ecological system tied in together.”
The system was developed by a group of contractors over about two months at a site covering about 1,000 square metres in Sharjah's Al Fao area. Mr Al Nuaimi employs technicians to run the site now.
How does it work?
Water from a fish tank is transferred into a second reservoir where, because the flow rate is lower, solid waste settles at the bottom.
The partially clarified water, containing ammonia released by the fish, is processed by microorganisms in a biofiltration unit to become nitrates, which can be taken up by plants.
Some of this nutrient-rich water is pumped to the hydroponic plant grow fields, where the roots are exposed to the water directly or are in a moisture-holding medium, such as gravel, fibre from coconut husks or clay pebbles.
After flowing through the hydroponic plant beds, the water is returned to the fish tanks that are stocked with species such as Nile tilapia.
Some water that passes through the biofilter is sent directly back to the fish tank, so there are two closed loops in the system.
Excess nitrogen-rich, high-saline water is used to irrigate palm trees on the same land.
If the pumps used are powered by solar power, the whole set-up can operate off-grid, Mr Al Nuaimi said.
A chicken coop has also been incorporated into the system, with the animals' waste, like that of the fish, being used to provide nutrients for the crops.
What could this mean for the future?
With the agroponic system, yields of leafy greens are about 10 times those of traditional farming, helped by having optimum nutrient conditions, a lack of seasonality, and a high density of planting.
Also, because growing conditions are carefully controlled, there is little spoilage, with nearly all plants reaching a suitable size to be harvested, a contrast to the situation often experienced with open farming. In total several tonnes of produce have been generated.
“A notable outcome of the pilot was the ability to produce food year-round with highly predictable yields. Unlike traditional farming in the region, which is limited by extreme heat (summers often lead to a collapse in production), the agroponic system maintained output year-round,” Mr Al Nuaimi wrote in the Emirati Journal of Business, Economics and Social Studies, published in December.
“This reliable multi-season performance is a major advantage in achieving food security, as it smooths out the supply of produce (vegetables and fish) across the year.”
The agroponic system produces food that could be classified as organic, and so could sell for higher prices, especially as there is demand in the UAE for locally grown, sustainably produced food.
Mr Al Nuaimi is confident that, if scaled up, the system could generate a profit, although making money has not been his primary motivation.
“The payout would be more giving back to science rather than turning a profit myself,” he said.
