Synergistic Effect of Co-inoculating Gum Liquid Inoculums of Rhizobium japonicum and Azotobacter chroococcum on Grain yield of Glycine max

Abstract

Rhizobium japonicum and Azotobacter chroococcum are known to be symbiotic and non symbiotic nitrogen fixing strains respectively. The main aim behind mixed inoculation is to achieve enhanced nodulation and grain production using gum as carrier rather than lignite . Lignite is not efficient in holding moisture due to which shelf life of bio-fertilizer decreases and cause pollution in production area. Worker in production area suffer from lungs diseases. To study the effect of inoculation with a mixed culture on yield of soybean was undertaken under field condition by random block method. Rhizobium japonicum, cultures were grown and maintained on yeast extract agar medium and Azotobacter chroococcum was grown on Jensen medium. Field trial was carried out by the seed treated with bacterial suspension having 10 9 cells /ml. The present findings revealed a significant increase in nodulation and grain yield in mixed culture with gums of both the strains against their control and inoculums in conventional carrier lignite. The effect observed after yield of crop the increase in grain yield around 42%. Present investigation confirms beneficial effects of mixed gum inoculum of Rhizobium japonicum and Azotobacter chroococcum against inoculums in lignite and single culture. The synergistic effect on crop yield is due to the various growth promoting substances like Auxins, Gibberllin and Indole 1 3 acetic acid secreted by Azotobacter chroococcum. This possibly is helpful in nitrogen fixation and nodulation, which is beneficial to the prolonged survivability of Rhizobium japonicum in presence of media containing gums. Gums are extracted from the trees. Two different gums are used as carrier as gums are efficient in holding moisture even at high temperature. This gums are nutritive too.