Astragalus sinicus L. in rice farming systems of southern China

摘要

Rice is the main crop in southern China. There are more than 20 million ha of paddy fields in this region, and one of the main cropping systems is two crops of rice followed by Astragalus sinicus L. (astragalus) In this system, early rice is transplanted in the second half of April, and harvested in the second half of July. The late rice crop is then transplanted and harvested in the second half of October. Astragalus is oversown in the second half of September, and ploughed in early April. There has been a long history of planting astragalus on paddy field in southern China. More than 8 million ha of paddy fields were sown with the species in the 1970s. It is used mainly as a green manure, and is the main green manure crop in China.