Farmers work in a plantation of Chinese wolfberry in Zhongning County of Zhongwei, northwest China's Ningxia Hui Autonomous Region, March 31, 2020. Local farmers of Zhongning County, known as the "hometown of Chinese wolfberry", started to get busy in spring ploughing. (Xinhua/Yang Wenxi)

Farmers work in a plantation of Chinese wolfberry in Zhongning County of Zhongwei, northwest China's Ningxia Hui Autonomous Region, March 31, 2020. Local farmers of Zhongning County, known as the "hometown of Chinese wolfberry", started to get busy in spring ploughing. (Xinhua/Yang Wenxi)

A farmer works in a plantation of Chinese wolfberry in Zhongning County of Zhongwei, northwest China's Ningxia Hui Autonomous Region, March 31, 2020. Local farmers of Zhongning County, known as the "hometown of Chinese wolfberry", started to get busy in spring ploughing. (Xinhua/Yang Wenxi)

Farmers work in a plantation of Chinese wolfberry in Zhongning County of Zhongwei, northwest China's Ningxia Hui Autonomous Region, March 31, 2020. Local farmers of Zhongning County, known as the "hometown of Chinese wolfberry", started to get busy in spring ploughing. (Xinhua/Yang Wenxi)

Farmers work in a plantation of Chinese wolfberry in Zhongning County of Zhongwei, northwest China's Ningxia Hui Autonomous Region, March 31, 2020. Local farmers of Zhongning County, known as the "hometown of Chinese wolfberry", started to get busy in spring ploughing. (Xinhua/Yang Wenxi)