Sodic soils are characterized by high pHs (>8.5),high ESP (>15) and variable electrical conductivity of soil saturation paste. These soils are very less organic carbon and microbial population. The sodic lands contain high concentration of sodium in their soil and difficult to cultivate. The applications of halophilic bacteria include recovery of salt affected soils by directly supporting the growth of vegetation thus indirectly increasing crop yields in salt affected soils. The present study was undertaken during 2018-19 for isolation of salt toerant bacteria from sodic soils that sustain in these soils and their formulation applications can increase nutrient uptake by the plants in sodic soils. The sodic soil collected from salt affected area in Ahemednagar district of Maharashtra was used for isolation of salt tolerant bacteria and these three isolates viz., STB-1, STB-2 and STB-3 were characterised morphological, physiological and biochemically. Out of these, all 3 isolates were white in colony colour and colonies were round, circular in shape. The bacteria were rod shaped and singular or pair habitat. The isolates STB-1 and STB-2 were Gram negative and STB-3 was Gram positive in reaction. All 3 STB isolates were streaked on Nutrient Agar medium plates containing different NaCl concentrations showed STB-1, STB-2 and STB-3 grew prolific at 3 and 5 per cent (slightly salt tolerant) and moderate at 7 per cent salt concentration (moderately salt tolerant). All STB-1 to STB-3 bacterial isolates were characterized biochemically viz., starch hydrolysis, H2S production, Catalase test, oxidase test, denitrification, Methyl Red test and gelatin liquefaction. All three STB were positive in oxidase and catalase in reaction. Out of 3 bacterial isolates, 2 isolates were positive in starch hydrolysis reaction and 1 was negative in starch hydrolysis, H2S production, Denitrification, Gelatin liquefaction. Thus, the salt tolerant bacteria were tentatively identified on the basis of morphological, physiological and biochemical characterization. The isolate-1 was found to be Pseudomonas spp. (STB-1), isolate-2 was Azatobacter spp. (STB-2) and isolate-3 was Bacillus spp. (STB-3). The consortia of salt tolerant bacteria viz., Azotobactor sp., Bacillus sp., Pseudomonas sp. is be useful for decreasing the pH of sodic soil and these consortia useful further for reclamation of Sodic soil.

Download this article as