RESUMO
Aim: Microbial community has an integral role in farming, but there is limited understanding of the complex response of microbial populations to organic and conventional farming systems. Therefore, the present study was carried out to study the effect of organic and conventional farming practices on soil microbial population in Haryana. Methodology: Fifty surface soil samples (0-15 cm) were collected from organic and their adjoining conventional farms at 11 districts of Haryana. Soil samples were processed and analyzed for Rhizobium, Azotobacter, Azospirillium and phosphorous solubilizing bacterial (PSB) counts for the two types of farming systems. Results: In comparison to conventional farming system, overall, population of PSB (which was 25.71×104 CFU g-1 soil) increased significantly to 36.91×104 CFU g-1 soil (an increase of 43.5%). Similarily, Rhizobium population in organic farming system increased from 29.26×104 CFU g-1 soil to 42.14×104 CFU g-1 soil (an increase of 44.1%). The population of Azotobacter increased significantly from 15.83×104 to 22.01×104 CFU g-1 soil (39.0%), while Azospirillium population increased from 13.66×104 to 20.10×104 CFU g-1 with an increase of 47.1%. Thus, it is clear from the results that organic nutrient sources showed a stimulating influence on the microbial populations of organic farming. Interpretation: Higher microbial population recorded in organic farming in comparison to conventional farming leads to better soil health and increased productivity.