BEIJING — China will expand trials of crop rotation and fallow systems to aid the green and sustainable development of agriculture, an agriculture official said on Feb 23.

The crop rotation and fallow systems will cover more than 50 million mu (around 8 million hectares) by 2020, said Zeng Yande, an official with the Ministry of Agriculture, at a news conference on Feb 23.

For 2018, the crop rotation and fallow systems will cover 24 million mu, expanding from 12 million mu in 2017 and 6.16 million mu in 2016, Zeng said.

China launched crop rotation and fallow systems in 2016 in nine provincial-level regions to relieve the burden on its arable land.

The crop rotation system is mainly in use in the country’s northeast, where corn and soybeans are grown, while the fallow system mainly covers farmland affected by environmental problems, including heavy metal pollution and desertification.

The systems have helped upgrade the agricultural structure and boosted green and sustainable growth, said Zeng.

The bottom line of the systems is to ensure China’s food security, and subsidies will be given to farmers who join the trials, according to Zeng.