Blue green algae are a group of gram negative photosynthetic prokaryotes mostly known as cyanobacteria which has drawn worldwide attention for the nitrogen fixing ability and their use in agriculture. BGA are very common in Indian in rice fields .The present study is focused towards develosping ecofriendly technique for mass production and suitable bio-inoculum development for field application of BGA strains. For that purpose three BGA strain namely Anabaena torulosa, Anabaena doliolum and Calothrix marchica were isolated from selected rice field of Assam, North East India. Growth behaviour and potentiality of all the three strains were explored in terms of their biomass production, chlorophyll –a and total chlorophyll content, packed cell volume (PCV) and their production of IAA like substances. The Intrinsic antibiotic resistance profile (IARP) test and compatibility study among the three aforementioned BGA isolates were also carried out for their efficient growth and biomass production for application and development of biofertilizer technology, three biowastes namely paddy straw, sugarcane trash and water hyacinth were analyzed for substrate preparation. It was Anabaena torulosa which showed maximum biomass yield of 18.33 mg/100ml and N-content of 10.16% obtained when paddy straw was taken as substrate. Again paddy straw showed best result of 28.16 mg/100ml and N-content of 20.33%, when composite inoculation of all the three stains was considered. Based on these findings an integrated BGA immobilized inoculum was also formulated with Luffa cylindrica which is locally known as bhol and with sugarcane trash. The experiment conducted was aimed to achieve suitable biofertilizer production at a very low cost using cheapest substrate which is far superior to harmful chemical fertilizers available in market.
