Studies tracing the flow of sap in date palm trees have shown that farmers are using more than twice as much water as is needed to irrigate the plants.
In Abu Dhabi, irrigation of date palm trees uses about a third of the groundwater spent on major crops, which has a serious impact on the sustainability of water resources.
The findings were part of joint research by the Environment Agency Abu Dhabi (Ead) and New Zealand.
“It is common practice for farmers to over-irrigate palm trees thinking that the trees will be in good condition if they receive enough water,” said Wafa Al Yamani, an assistant scientist at Ead.
“However, over-irrigation of date palms and other crops in general has a negative effect on the plants because a lot of water is drained in a short period of time away from the root zone. There are also negative effects on the groundwater quantity and quality.”
Date palms need an average of 300 litres of water a day.
This year, Ead signed an agreement with New Zealand for field experiments monitoring the flow of sap in palm trees. The information will enable scientists to tell whether irrigation water is used efficiently.
The experiments are carried out by the International Centre for Biosaline Agriculture in Dubai.
Preliminary findings showing trees were overwatered by as much as two and a half times more than the amount suggested by the UN Food and Agriculture Organisation.
The field experiments are expected to give decision-makers advice on how to best balance the requirements of palm farmers against the need to conserve water.
“Knowing the sap flow of date palms will help in determining the actual water consumed by these palm trees, as not all water used for irrigating them is actually consumed by the tree itself,” said Ms Al Yamani. “Some is lost through drainage and through evaporation.
“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, salinity of water and other factors, we will be able to allocate the right amount of water for irrigation in the agriculture sector.”
Like the rest of the UAE, Abu Dhabi is faced with a rapid increase in the use of water resources.
In 2011, total consumption reached 3.3 billion cubic metres and it is expected that demand will increase to about 5 billion cu metres by 2030.