While much of China endures summer heat waves, Guyuan, a city in the Ningxia Hui autonomous region with an average temperature of just 18 C, has big plans for potatoes and cool-season vegetables.

"Guyuan was once considered one of the least habitable places due to its barren land, frequent sandstorms, lack of vegetation and water scarcity," said Hua Zhimin, Party chief of the city. "Significant changes have occurred thanks to decades of afforestation and soil and water conservation efforts."