Over-watering threatens Abu Dhabi date palms

Date palm trees need only 300 litres of water a day to flourish, but many farmers have been pouring 2,100 litres, making them susceptible to pests, diseases and weakening their roots. Eighty-six per cent of the water is wasted because of this over-watering. Despite being a water-scarce region, Abu Dhabi has the highest per capita water consumption in the world. The average per capita consumption in Abu Dhabi is 550 litres per day, compared to the global average of 350 litres. The agricultural sector alone consumes 1.5 billion cubic litres of water a year, which is 52 per cent of the total consumption of the emirate. The Abu Dhabi Farmers Service Centre (ADFSC) said many date palms have been damaged because of over-watering, though there are no official figures available. The centre is starting to conduct field trials on the farms, using sensitive computer-linked soil moisture meters. The information generated will be used by ADFSC to provide recommendations on optimum requirements of water per tree. The ADFSC has begun a programme to upgrade irrigation delivery systems on all farms. This includes providing equipment to better control water usage. “Our irrigation unit head ran a study in Hameem, in the Western Region of Abu Dhabi. He and his team recommended 30 minutes of watering per tree per day, down from an average 3.5 hours per tree per day. Farmers who followed the instruction said the trees looked better and had fewer incidences of pest and diseases,” Christopher Hirst, CEO of the centre, said. Many farmers think that palm trees perform better with a lot of water. But the opposite is true. Over-watering makes them weak. Also, in the sandy soils of the region, excess water drains rapidly through the soil. It will leech whatever little bit of nutrients might be there in the soil and deprive the plants of the benefits. The only reason why most palms do not die in spite of over-watering in the UAE  is because the soil is so sandy that it does not retain that excess water, Hirst said. It is a popular misconception among farmers that the base of the tree trunks should be wet. On the contrary, it is important to keep the base of the trunk dry, ADFSC said. The centre recommends that any irrigation system should be placed at a distance of at least one metre from the base of the tree to prevent the trunk from becoming wet. If the base of the trunk is regularly watered then adventitious roots start to form on the trunk. These provide easy access to  pests such as the dreaded red date palm weevil. One hindering factor in most farms is that the farm labourers generally come from countries that follow flood irrigation techniques. In such places, excess water is always applied because it is in plentiful supply and the soil there can absorb and hold the extra water for use by the plants later. This, however, does not work in a desert land like that of the UAE. Another problem is the lack of uniformity in the irrigation systems. If water is in short supply to one tree, the farmers keep the water running until that particular tree has enough of it. In the process, the other trees are in danger of an over-supply. Date farmers in the UAE do not really know the right quantity of water that their trees need. In Abu Dhabi, before the establishment of  the ADFSC, there were no studies done to determine the right quantity of water to ensure an optimum yield. “We’re in the process of educating farmers about correct irrigation practices through our on-farm demonstrations and training sessions,” Hirst said.