NITROGEN FIXATION EVALUATION OF AZOTOBACTER CHROOCOCCUM ISOLATED FROM SOIL OF FOREST

Abstract

With the continuous use of chemical fertilizers in Agriculture system may help to produce sufficient amount of food for growing population but these chemicals have an adverse effect both on the environment and living organisms. Biofertilizers are a promising alternative to hazardous chemical fertilizers and gaining importance for attaining sustainable agriculture. They play key role in maintaining soil health and plants. Microorganisms can interact with the crop plants and enhance their immunity, growth, and development. Nitrogen, Phosphorous, Potassium are the essential nutrients required for the growth of crops, but these nutrients are naturally present in insolubilized forms. Certain microorganisms make them soluble and can be easily assimilated by plants for their growth and development. In this study, Azotobacter chroococcum were isolated from forest surroundings of Panbari Dharan. 25 soil samples were collected in sterile bag and cultured in Ashby’s media by serial dilution and incubated at 30˚C for 5 days. Morphological, cultural, biochemical characterization was done and bacteria were identified. Isolated A. chroococcum was cultured in Ashby’s broth and inoculated on tomato seedlings by root dipping technique. It was found that tomato plants inoculated with A. chroococcum has significant growth in height, no. of leaves and root length than that of untreated tomato plants. The research result showed that this strain had positive effect on the increase of nitrogen content of soil. On the base of this study, it is concluded that Azotobacter chroococcum has positive effect in growth of plants. It could be good biofertilizer as an alternative to nitrogen fertilizer.