Effect of nano-hydrophobic sand layer in datepalm (Phoenix dactylifera L.) cultivation in aridlands

There are no previous reports regarding the use of hydrophobic sand layer in aridland agriculture datepalm cultivation. In this study we tested the influence of different layers of nano-sand (hydrophobic sand) to reduce soil water requirements, and plant growth performance. Hydrophobic sand made by using nanotechnology is a novel concept, in which the natural sweet sand is coated with nano particles of pure silica by vapours of a silicon compound called trimethylhydroxysilane (CH₃)₃SiOH by special chemical treatment. Datepalm (Phoenix dactylifera L.) tree is the most popular and important tree in UAE, it is mainly cultivated in sandy soil. This type of soil is characterized by low organic matter, high infiltration rate, and low water holding capacity, low nutrient holding capacity and low fertility. Under these conditions, hydrophobic sand may be a key factor in improving the crop growth. The objectives of this investigation were to evaluate the effect of hydrophobic sand application on growth of datepalm, to determine the uptake of nutrients and heavy metals by crop and to evaluate the major chemical and physical properties of the soil as affected by hydrophobic sand application. The results were promising, the application of hydrophobic sand gave the highest shoot and root fresh and dry weights of datepalm seedlings compared to control. Root length of datepalm seedlings was strongly affected by application of hydrophobic sand especially in the second growing season 2009-2010 in which there was 40% increment in the root length compared to control. The results of heavy metal concentrations in date palm leaves and roots showed that the heavy metal levels (Cd, Mo, Pb and Se) were within the recommended level. The heavy metal concentrations in datepalm soil were within the recommended level.