Software could help to save up to 80 per cent of water used on UAE farms

Farmers currently use about three times the amount of water they need, says study

Brent Clothier, left, says that by using sap-flow monitoring, they were able to measure how much water a date palm tree used. Photos by Pawan Singh / The National

Studies tracing the flow of sap in date palm trees in the UAE have shown that farmers are using nearly three times more water than is needed.

Dr Ahmed Al Muaini and Brent Clothier at the experiment site at the International Centre for Biosaline Agriculture in Dubai.

A date palm that was irrigated with water high in salinity.

Research showed that common practice by farmers was to irrigate each tree with about 300 litres of water each day throughout the year.

The field experiments were carried out to give decision-makers advice on how to best balance the requirements of palm farmers against the need to conserve water.

Brent Clothier shows where the sap flow probes were inserted on the date palm.

The UAE's farmers can now use new software that helps to plan crop planting and also calculate how much water their land will need over a year.

A study carried out over many years to trace the flow of sap in date palm trees showed that farmers are using nearly three times as much water than they need to irrigate their plants.

It found that farmers typically irrigate each tree with about 300 litres of water a day.

However, by measuring the amount of sap flowing in the trunk of a date palm, researchers found they could cut that to 180 litres a day during the summer, and to as little as 60 to 80 litres in winter. This would save up to 80 per cent of the water used on the country's farms.

Part of a joint research project by the Environment Agency – Abu Dhabi and New Zealand Plant and Food Research, the experiments provided advice on how to balance the requirements of date farmers and the need to conserve water.

“Back in 2014, for the first time ever we were able to measure how much water, directly, a date palm tree used,” said Dr Brent Clothier, principal scientist on the project.

“We found that the amount of irrigation that was being applied was three times greater than what the date palm needed.

“What we have done is put all of that knowledge into a software tool that now exists within the Environment Agency – Abu Dhabi so that it can allocate water more sustainably, not only to date palms but a whole range of crops here in the Emirates.”

The crop calculator software allows users to determine the best location and soil to grow certain crops, and the exact amount of water it needs throughout the year.

Understanding the sap flow within a date palm helps to determine the amount of water being consumed by a plant, as not all water used for irrigation is consumed by the tree.

Long probes were inserted into the trunks of date palms at the International Centre for Biosaline Agriculture in Dubai to measure sap flow.

Researchers used a “heat dissipation method to monitor flow” in date palms, which in turn led them to understand the transpiration, or loss of water vapour.

From there, they could determine how much water the tree was using to thrive.

Species of date palm were put into three categories: low salinity irrigation, medium salinity and high salinity.

The scientists found the plants in the low salinity section needed more water but grew taller and gave a better date yield.

The plants in the high salinity section were smaller in size and produced less yield, but required less water.

“The fruits are completely different between the low salinity irrigation to the high salinity,” said Dr Ahmed Almuaini, groundwater project manager at the agency.

“The [fruit from the] low salinity section is very tasty. You feel it, there is sugar. But the high salinity [fruit] has less sugar and is a little bit dry.

“We now have this software tool created from this research which we are hoping to start using at the agency every soon.”

He said by taking into consideration all the factors that play a role in the amount of water consumed by each tree in different places in the emirate, such as soil, climate, plant size and type, the salinity of water and other factors, they will be able to allocate the right amount of water for irrigation.

In a hot and arid desert such as the UAE, farmers are often limited with the amount of crop they can produce using traditional farming methods.

However, the UAE’s agricultural sector is a significant user of the country’s limited resources, accounting for approximately 72 per cent of fresh water consumed.

Despite heavy water consumption, the sector produces less than 20 per cent of the UAE’s food.

By using technology to measure the exact amount of water they need, farmers could help slow down the speed at which ground and freshwater reserves are being consumed.