Mulch is used to help the soil retain its moisture. We tend to think of mulch as something organic made from materials such as bark chips or dead leaves, but the reality is mulch can take the form of plastic. In fact, many farmers use a plastic form of mulch to keep the soil moist. This involves laying sheets of polyethylene plastic over the crop plants to reduce weed growth, prevent erosion, retain moisture, and boost soil temperature.
But there are many problems with the sheeting, environmentally speaking. For one, the process of producing it is resource-intensive. Plus, once it gets worn out, it’s typically just removed and dumped in a landfill. Not to mention tiny plastic particles wind up in the soil and into your produce.
OK. Enough with the problems, let’s talk solutions to this plastic mulch. At the University of Nevada in Las Vegas, scientists have figured out that soaking sand with soybean oil creates an effective alternative to plastic mulch.
As reported in New Atlas, the process works by combining equal volumes of sand and soybean oil, heating the mixture for about an hour, then allowing it to cool. This process causes a coating around each individual grain of sand.
In lab tests, the oil-coated sand proved more than capable of preventing the water in the soil from evaporating. Compared to control samples of bare soil, the sand-covered soil had up to 96 percent lower evaporative water loss, leading researchers to believe that this sand-soybean oil mixture could serve as a much more sustainable alternative plastic film mulch.
Image source: Michael Nicholl
