Farmers weed a vegetable field in Hechi City, south China's Guangxi Zhuang Autonomous Region, Feb. 24, 2009. Due to harsh stony desertification, people from dozens of counties and districts in Guangxi had long been poverty stricken. Recent years, a comprehensive environmental control program has been carried out to control stony desertification for poverty alleviation purposes. (Xinhua/Zhang Ailin)