When EM is applied to soil or plant leaf surfaces, the populations of photosynthetic bacteria and nitrogen fixing bacteria increase dramatically. The phenomenon is associated with the growth of more vigorous plants, higher plant yields and improved crop quality compared with no EM treatment. It was thought that the high number of photosynthetic bacteria and nitrogen fixing bacteria in soil and at leaf surfaces might enhance the plants photosynthetic rate and efficiency, and its nitrogen fixing capacity.
Improved yields in Maize Crops - http://www.emnz.com/asset/library/Improvement%20in%20BNF%20%20yield%20of%20groundnut%20by%20EM.pdfFixing%20atmospheric%20nitrogen
The concepts and Theories of Effective Microorganisms - http://infrc.or.jp/english/KNF_Data_Base_Web/PDF%20KNF%20Conf%20Data/C1-5-015.pdf