Technicians operate unmanned aerial vehicles to fertilize paddy fields at Balidian Town in Wuxing District of Huzhou City, east China's Zhejiang Province, July 10, 2020. Unmanned aerial vehicles are used to conduct fertilization work above more than 3,300 mu (220 hectares) of paddy fields here recently.Photo:Xinhua

Aerial photo taken on July 10, 2020 shows unmanned aerial vehicles fertilizing a paddy field at Balidian Town in Wuxing District of Huzhou City, east China's Zhejiang Province. Unmanned aerial vehicles are used to conduct fertilization work above more than 3,300 mu (220 hectares) of paddy fields here recently.Photo:Xinhua

An unmanned aerial vehicle fertilizes a paddy field at Balidian Town in Wuxing District of Huzhou City, east China's Zhejiang Province, July 10, 2020. Unmanned aerial vehicles are used to conduct fertilization work above more than 3,300 mu (220 hectares) of paddy fields here recently.Photo:Xinhua

An agriculture cooperative staff member fills an unmanned aerial vehicle with chemical fertilizer at Balidian Town in Wuxing District of Huzhou City, east China's Zhejiang Province, July 10, 2020. Unmanned aerial vehicles are used to conduct fertilization work above more than 3,300 mu (220 hectares) of paddy fields here recently.Photo:Xinhua