Wax-Coated Sand Boosts Agri Yields in Arid Regions by Keeping Soil Wet Longer

As soil dries out rapidly in dry, hot climates, it is difficult to cultivate plants. Farmers in arid and semi-arid areas irrigate their crops with subterranean irrigation tubing networks and cover the ground with plastic sheets as a result.

However, plastic sheets are costly and wasteful. Researchers have now devised a simple, biodegradable ground cover- wax-coated sand- that keeps the soil moist and enhances crop yields, according to a study published in ACS Agricultural Science & Technology.

Farmers frequently collect water from neighbouring waterways or underground aquifers to irrigate their crops. When growing plants in arid places, where the soil is primarily sand and can't hold onto water properly, these supplies might quickly decrease.

One strategy to improve the efficiency of irrigated water is to make sure it stays in the soil long enough for plant roots to absorb it. Ground cover barriers, such as plastic sheets and synthetic nanomaterials, have been found in previous experiments to decrease evaporation and improve plant growth and agricultural yields.

Both, however, have the potential to leak undesirable substances into the soil, with unclear long-term consequences.

Some plants and animals create waxy compounds that capture and pool water from fog or condensation in order to gain access to these moisture sources. Himanshu Mishra and colleagues were inspired by nature and wanted to test whether they could coat sand with wax to create an environmentally friendly ground cover to minimize soil evaporation.

For their trials, the researchers used refined paraffin wax, a biodegradable product that is widely available. They dissolved the wax in hexane and mixed it with silica sand.

As the solvent evaporated, a 20-nm-thick wax covering was left on the grains. When the researchers placed the wax-coated sand in a thin layer on an open field in Saudi Arabia, it reduced soil moisture loss by up to 50%–80%.

Tomato, barley, and wheat plants mulched with the novel material produced significantly more fruit and grain than those growing on uncovered soil, according to field testing.

Furthermore, the waxy mulch, which may have served as a food source for some of the microorganisms, had no negative impact on the microbial population around the plants' roots and in the soil. According to the researchers, this basic nature-inspired device could make water consumption more efficient in arid locations.

(Source: American Chemical Society)