The nutrient situations in the major alfalfa producing areas of China

In order to clarify the availability of soil nutrients and the nutrition situation of alfalfa plants (Medicago sativa) in the major alfalfa producing area in China, soil and plant tissue samples were collected in 21 areas, the nutrient levels in both the soils and plant tissues in the early flowering stage of alfalfa were analyzed, and the first harvesting yields of grass and the reasonability of present fertilization were investigated from May to June 2012. The relationship between the nutrient supply and the yields was evaluated at the same time. The results show that the major alfalfa producing areas are mainly sandy soils with low levels of organic matter contents. The nitrogen（N）nutrition in alfalfa is sufficient, but phosphorus（P）and potassium（K）are inadequate in general, and trace elements such as zinc（Zn）, boron （B）and molybdenum（Mo）are often deficient. The P in soils, B, Mo and Fe contents in plant tissues are significant and positively correlated with the yield of the first harvesting (P0.05). Among the investigated fields, N fertilizers are applied in 12, P fertilizers in 5 and K fertilizers in 3 sites. Therefore, applications of P and K and trace elements B and Mo fertilizers should be taken as an effective way for the yields increase of alfalfa.