Soil microbial dynamics and enzyme activities as influenced by biofertilizers and split application of vermicompost in rhizosphere of wheat (Triticum aestivum. L.)

Aim: A field experiment was conducted during rabi season to determine the effect of biofertilizers and split application of vermicompost on biological properties (microbial biomass carbon and nitrogen, microbial populations and enzyme activities) in rhizosphere of wheat. Methodology: The experiment was laid out in factorial randomized block design with three replications consisting of twenty treatment combinations. Soil samples were collected from the plots at 0-15 cm depth after harvest of wheat crop and soil biological properties analyzed using standard analytical procedure. Results: The experiment results indicated that among biofertilizers treatments, seed inoculation with Azotobacter + PSB + KMB + ZnSB (B5) resulted in a significant higher soil microbial biomass carbon, microbial biomass nitrogen, population of bacteria, fungi and actinomycetes, dehydrogenase activity and acid phosphatase enzyme activity in comparison to control. Similarly, application of vermicompost as 50 % VC at sowing + 50 % VC at tillering (V3) were obtained improved microbial biomass carbon and nitrogen, microbial population, dehydrogenase activity and acid phosphatase enzyme activity while remaining at par with 75 % VC at sowing + 25 % VC at tillering (V4) proved superior in comparison to rest of the treatments due to continuous supply of nutrients throughout the crop cycle. Grain and straw yield of wheat also increased due to the application of biofertilizers and vermicompost over the control. Interpretation: Biofertilizers (Azotobacter, PSB, KMB and ZnSB) and split application of vermicompost enhanced the soil microbial population and enzymatic activities which sustained the soil health for better wheat production.