Abstract:
The present investigation was aimed at producing biofertilizers using a consortium of diazotroph and phosphorous solubilizing bacteria and determining the effect of biofertilizers application on the growth of maize plants. Azotobacteria and Phosphobacteria are amongst the most vital components of biofertilizer. Biofertilizers are the formulations of living microorganisms, which have the ability of fixing atmospheric nitrogen in the soil and thereby, increasing the crop yield. They play essential roles in solubilizing of phosphorous in soil for utilization by plants. These organisms enrich the soil through their metabolic activities. Mass production of pure cultures was carried out at the optimized condition in batch fermentation using specific medium forPhosphobacter and Azotobacter. Initially, organisms were isolated from the soil sample and confirmation was done using the biochemical test. The concentration of phosphorous, total nitrogen, nitrate, nitrite, ammonium and total organic carbon were determined in the individual setups; Phosphorous solubilizing, nitrogen fixing and in the consortium of the organism. The effect of the biofertilizer produced was tested on the growth parameters using maize plants. After 21 days of germination, phenotypic observations showed significantly high performance in plant length (cm), mass of whole plant (g), number of roots, length of roots (cm), total length of plant (cm), breadth of leaves (cm), shoot length (cm), root mass (g) and biological average yield (%). The biochemical parameters showed significant increase (P<0.05) in chlorophyll content (mg/g.fr.wt) as recorded in Control (0.010+0.000), Phosphobacter (0.016+0.000), Azotobacter (0.016+0.000) and combination treatment (0.018+0.000). Significant increase (P<0.05) in carbohydrate content (%) was recorded at Control (51.976+0.768), Phosphobacter (69.690+0.500), Azotobacter (69.656+2.355) and combination treatment (70.190+0.500). Significant increase (P<0.05) in protein content (g) was recorded at Control (0.028+0.001), Phosphobacter (0.040+0.000), Azotobacter (0.060+0.001) and combination treatment (0.061+0.000). In all the treatments, Azotobacter with Phosphobactertreated plants shows significantly (P<0.05) maximum growth when compared with single inoculations and control. The overall results suggest that biofertilizer inoculation improves plant mineral concentration through nitrogen fixation and phosphorous solubilization.
