Azure, also known as fresh green, is an annual erect herb with single stem in Leguminosae. Tianqingxi has a warm climate, strong drought resistance, insect resistance, salt tolerance, waterlogging tolerance and barren tolerance, and is a pioneer crop for improving saline-alkali land. There are early, middle and late-maturing varieties, and the whole growth period is 100- 150 days, and the late-maturing varieties have higher grass yield.