Aerial photo taken on Feb. 28, 2019 shows farmers working in a field in Pinggui District, Hezhou City, south China's Guangxi Zhuang Autonomous Region. (Xinhua/Liao Zuping)

A farmer picks cherry tomatoes at a greenhouse in Fuwan Village, Zaozhuang City, east China's Shandong Province, Feb. 28, 2019. (Xinhua/Sun Zhongzhe)

A farmer waters the field in Qiaotou Village, Qionghai City, south China's Hainan Province, Feb. 28, 2019. (Xinhua/Meng Zhongde)

A farmer picks tomatoes at an organic vegetable greenhouse in Ceyu Town, Jingxing County, Shijiazhuang City, north China's Hebei Province, Feb. 28, 2019. (Xinhua/Wang Baolong)

A farmer trims cherry tree branches in Dazhangtun Village, Tangshan City, north China's Hebei Province, Feb. 28, 2019. (Xinhua/Liu Mancang)

A farmer plants chives in Longjing Village, Dafang County, Bijie City, southwest China's Guizhou Province, Feb. 28, 2019. (Xinhua/Luo Dafu)

A farmer works at a cucumber greenhouse in Dazhangtun Village, Tangshan City, north China's Hebei Province, Feb. 28, 2019. (Xinhua/Liu Mancang)

Farmers plant watermelon seedlings at a greenhouse in Longshan County in the Tujia and Miao Autonomous Prefecture of Xiangxi, central China's Hunan Province, Feb. 28, 2019. (Xinhua/Zeng Xianghui)

Farmers picks early spring tea leaves in Zhiyaoping Village, Xuan'en County, central China's Hubei Province, Feb. 28, 2019. (Xinhua/Song Wen)

A tractor works in a field in Qianzhao Village, Tancheng County, east China's Shandong Province, Feb. 28, 2019. (Xinhua/Fang Dehua)

Staff members trim cherry tree branches at a garden in Chengzi Village, Shijiazhuang City, north China's Hebei Province, Feb. 28, 2019. (Xinhua/Liang Zidong)