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Sand Coated With Wax Improves Crop Yield As It Keeps Soil Wet Longer In Arid Regions

May, 2022

Searching for an alternative to plastic sheets to hold moisture in soil, scientists found that using sand coated with wax could be greener and cheaper way to keep to soil moist and improve crop yield

Farmers commonly use plastic sheets along the crop rows on the ground to maintain the wetness of the soil to improve the crop yield. Now, a team of researchers at King Abdullah University of Science and Technology (KAUST) while searching for an alternative to plastic sheets, found that using sand with coating of purified paraffin wax could be a cheaper, greener and efficient way to maintain the moisture of soil and improve crop yield.

While finding the alternative, the in the beginning dissolved the wax in hexane solvent and mixed sand into that mixture, which then allowed the solvent to evaporate. This left the hydrophobic or water repelling layer of 20 nanometer thick wax on every sand grain. This process now has been made so advanced that it requires no solvents. Then the team spread this superhydrophobic sand (SHS) on a slim layer in a field in Saudi Arabia and found that this approach reduced loss of soil moisture by 56 to 78%. Moreover, this SHS was then used for multiple crop growing seasons as 5 to 10 mm thick layer for barley, tomato plants and wheat, where it improved the crop yield and the plant production of grains and fruits was 73% more than a group of plants with uncovered soil.

Furthermore, the additional benefits of this SHS was that it did not affect the diversity and amount of good microbes in soil. Even though the paraffin wax in its regular form is not considered environment friendly, the food grad purified wax used in this study is biodegradable and also non-toxic. Thus, it is unlikely to be harmful for the environment or to build up in it.