Workers use agricultural machinery to harvest potatoes in the Chabei Administrative District of Zhangjiakou City, north China's Hebei Province, Aug. 13, 2015. There are over 1.7 million mu (113,333 hectares) of potato fields in Zhangjiakou, with an average yield of 2,200 yuan (343 U.S. dollars) per mu. (Xinhua/Yang Shiyao)
