A man sprays water on sweet potatoes used as seeds at a greenhouse in Xinhu Village of Donghuangtuo Town in Luannan County, north China's Hebei Province, April 5, 2019. Luannan County has been committed to developing agriculture to boost farmer's income. So far, the county has a planting area of about 200,000 mu (about 13,333 hectares), generating a total value of over 3 billion yuan (about 446 million U.S. dollars) a year. (Xinhua/Yang Shiyao)