Effects Of Inoculation With Different Rhizobium On Three Alfalfa Varieties And Soil Nutrients

One of the most important ways to establish an efficient,high-yield,high-quality alfalfa production system is to inoculate alfalfa with efficient rhizobium.The efficiency of alfalfa-rhizobia symbiotic nitrogen fixation must consider the synergistic effect among the host plant,rhizobium and environment.There are many types of alfalfa that are popularized in the western region of Inner Mongolia,but few high-efficiency rhizobium strains that can be symbiotically matched with different varieties of alfalfa.The excellent alfalfa nodule strains that are compatible with different varieties of alfalfa and are highly competitive and have high nodulation rate are selected through experiments and applied to actual agricultural production promotion.It is an important method to improve the yield and quality of alfalfa in our region.It is also an effective measure to improve salinized land and increase soil nutrients in our region.In this study,six nodule strains of alfalfa interconnected races screened by predecessors were selected with Medicago varia Martin.cv.Caoyuan No.3 and M.sativa L.cv.Aohan)and Adinalin(M.sativa L.cv.Adrenalin)for inoculation matching screening,through the plant height,single plant biomass,nodulation,crude protein,phosphorus,potassium and changes in soil nutrients and other indicators The strains with high matching degree with the three varieties were screened out,and the changes of soil nutrients after inoculation were determined.The findings are as follows:(1)The suitable growth strains of the three alfalfa varieties are different.Among the 6 strains inoculated,Medicago varia Martin.cv.Caoyuan No.3,M.sativa L.cv.Aohan,and M.sativa L.cv.Adrenalin had better growth-promoting effects.SJN strain.The above-ground biomass of alfalfa per plant in the first year of growth can be increased by 60%,71%,and 64%.(2)The quality of alfalfa inoculated with different strains varied in different degrees.Among them,Medicago varia Martin.cv.Caoyuan No.3 inoculated with XBC strain can significantly increase its crude protein content;M.sativa L.cv.Aohan inoculated with XBC and XH strains significantly increased its phosphorus and potassium content;M.sativa L.cv.Adrenalin The crude protein content of the inoculated SJN strain increased significa-ntly,but had no significant effect on the phosphorus and potassium content of the plants.(3)After Medicago varia Martin.cv.Caoyuan No.3 and M.sativa L.cv.Aohan were inoculated with rhizobium,the total nitrogen,total potassium,total phosphorus,total carbon and some quick-acting indicators in the soil decreased,but the ratio of carbon and nitrogen increased.After M.sativa L.cv.Adrenalin was inoculated with rhizobium,total potassium,pH,and carbon-nitrogen ratio decreased,but the other indicators increased significantly.