Saline soil is a very important nonbiological force factor influence agricultural production and ecological environment. How to use the great area saline soil and improve the tolerance of salt is an important research subject in bioscience. The alfalfa is a kind of perennial high-quality legume family herb that is praised as “king of herb”. It has agreeable taste and costly nutrition, and has a good adaptability. It is able to bear the drought and resist cold, and has a good ecological benefit to ecological...