Microbial population and nutrient dynamics in rhizosphere soil of direct seeded rice

A field experiment was undertaken to investigate the microbial population and nutrient dynamics in rhizosphere soil of direct seeded rice (DSR). The research was conducted at ARS, Dhadesugur during the year 2015–16. The experiment was laid out in randomized block design with ten treatments and three replications. Among all the treatments, combined inoculation of Azospirillum + PSB + AMF + 75% N + 75% P + 100% K recorded significantly higher soil microbial population with respect to bacteria (6.04 x 10⁶ cfu g⁻¹ dry soil), fungi (7.89 x 10³ cfu g⁻¹ dry soil), actinobacteria (7.11 x 10⁴ cfu g⁻¹ dry soil), Azospirillum (39.30 x 10² cfu g⁻¹ roots), PSB (8.01 x 10³ cfu g⁻¹ dry soil) compared to individual and dual inoculation. Similarly, per cent root colonization, spore count of AM fungi, soil biomass carbon and chemical properties of soil performed better with combined inoculation of efficient strains of Azospirillum, PSB and AM fungus as compared to other treatments and uninoculated control.