The book covers concept and relevance of organic agriculture in 16 chapters as organic farming, basic information on biofertilizers, classification of biofertilizers, nitrogen fixation, Rhizobium, Azolla, Azotobacter, Azospirillum, blue green algae, phosphorus solubilizing micro-organisms (PSMs), Mycorrhizae, Frankia, vermiculture and vermicomposting, liquid biofertilizers, production, quality and marketing of biofertilizers & some important media. The book is written in a very simple form with up to date data and statistics. We have put the references of all chapters at the end of book that we hope will be useful to you. It is a mostly all-inclusive basic textbook on organic farming system and will specifically meet out the requirement of the scientists, teachers, research scholars and students of both the urban and non-urban areas.