WHITE MULCH: Aerial view of farm land using plastic soil cover. Hubei province, central China.© JIE ZHAO/GETTY IMAGES
White stripes, each about a meter wide, painted the land for as far as the eye could see. I was visiting the dry areas of the autonomous Ningxia region in northwest China with colleagues from the Chinese Academy of Agricultural Sciences and the nonprofit Centre for Agriculture and Biosciences International. Those strips of plastic sheeting, I was told, allow farmers to grow cash crops and grains despite the desert-like conditions. The sheets, usually composed of polyethylene, help conserve water, suppress weeds, and boost soil temperatures, effectively increasing crop yields by 20 to 60 percent.
The use of plastic “mulch” to grow crops, known as the White Revolution, began in China in the late 1970s, and now covers 20 million hectares of the country’s agricultural land, ...
