In the land between Israel and Jordan, about two kilometers from the Dead Sea, where soils are heavily salted and rain seldom falls - and where August temperatures average 50 degrees Celsius - a permaculture experiment has already proven that one can grow fruit trees in the desert.

Now, a company located in the United Arab Emirate (UAE) called DIME Hydrophobic Materials has produced a hydrophobic, or water-resistant sand that - spread on the ground or layered on a sheet using nanotechnology - could prevent precious desert moisture from leeching below plant roots.

This micro-thin blanket of "super sand" is currently being produced at the rate of 3,000 tons per day, and promises a revolution in desert agriculture to rival the ancient Egyptian dikes and canals that once converted arid landscapes from bleak to flourishing.  

As DIME engineer Fahd Mohammad Saeed Hareb explains, laying a sheet of waterproof sand beneath desert topsoil could combat increasing desertification and encourage plant growth in even the most arid climates, where farmers currently have to water their crops five or six times a day simply to keep them alive. This would decrease water use up to 75 percent. It would also prevent underground salt deposits, so common to deserts, from migrating into the plant-root region and killing crops that are not salt-tolerant. 

Desert soils are saline because rainfall is low. Any rainfall that does occur is usually blown inland from the sea, and rainwater that doesn't run off evaporates, leaving behind salts that accumulate near the top of the soil. Eventually, the soil is so saline that most crops can't grow.

Flooding such soils with vast quantities of water - even if this were possible - results in standing water high in salts because desert soils are commonly underlain by more impervious layers like basalt and compacted clay. Additionally, most desert terrains are flat, eliminating the possibility of drainage. This standing water is even more detrimental to crops, and results in more salt accumulating in soil once the water does evaporate.

For proprietary reasons, the company isn't revealing the precise nature of the nano coating being used, but instead calls it SP-HFS 1609. The formula has, however, been approved by Germany's Federal Environment Agency (or FEA, known in Germany as the Umweltbundesamt), which confirms it is ecologically safe.

This hydrophobic sand, less than 14,000 micro-millimeters thick and sold either in bulk or sandwiched between sheer layers of polyethylene, is available in kilograms or rolls up to 50 meters in length. Coating (on one length) can be done in less than 45 seconds, and enough hydrophobic sand polyfilm produced in four days to cover one square kilometer. The eventual goal is to convert up to eight percent of UAE land to arable soil by 2015, as compared to the 3.7 percent it is at today. 

Brandenburgische Technical University Cottbus in Germany has verified that the sand rolls can support up to 104 newtons (a measure of force) per square millimeter. This is immensely strong for such thin layering, and insures that the substance will support the necessary layers of soil, water, and plants - and the weight of farmer's walking their fields - without tearing.

At Al Ain, the UAE's main university, where the hydrophobic sand has been tested since December of 2007, date palms, grasses and rice have all been grown successfully. The date palms are no surprise, since they are saline-tolerant and grow with minimal moisture. The rice is astonishing, and the product, if successful, could lead to a revolution in food-growing techniques in arid regions like the UAE, Africa, India and parts of Australia.

In these regions, where tensions over rising populations, food availability and water scarcity grow ever more troublesome, hydrophobic sand, at the rate of one ton for ten square meters, could prevent future humanitarian disasters like mass starvation and territorial wars over arable land.

Related Reading:
Are Deserts Hidden Carbon Sinks?
Climate Change: The Desert, The Mirage, and The Last Chance Saloon

Image Credits:
Nextbigfuture.com