Agricultural machinery collect wheat straw in the field at Haizhou District in Lianyungang, east China's Jiangsu Province, June 12, 2019. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest. (Photos: Xinhua)

A farmer operates a tractor to collect wheat straw in the field at Wangyaobao Village of Jiazhai Township in Liaocheng City, east China's Shandong Province, June 12, 2019. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest.

Aerial photo taken on June 12, 2019 shows farmers stacking the collected wheat straw in the field at Luwu Village of Jiazhai Township in Liaocheng City, east China's Shandong Province. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest.

Aerial photo taken on June 12, 2019 shows agricultural machinery collecting wheat straw in the field at Liubao Township in Baoying County in Yangzhou, east China's Jiangsu Province. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest.

Aerial photo taken on June 12, 2019 shows agricultural machinery collecting wheat straw in the field at Liubao Township in Baoying County in Yangzhou, east China's Jiangsu Province. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest.

A farmer transports the collected wheat straw in the field at Luwu Village in Jiazhai Township in Liaocheng City, east China's Shandong Province, June 11, 2019. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest.

A farmer operates a tractor to collect wheat straw in the field at Wangyaobao Village of Jiazhai Township in Liaocheng City, east China's Shandong Province, June 12, 2019. The recycling of wheat straw is commonly conducted with the ongoing wheat harvest.