A field experiment was conducted to study the efficacy of liquid biofertilizers under different methods of application were seed treatment, soil application and drip fertigation in greengram on availability of soil nutrients and soil microbial biomass carbon. A Field experiment was carried out at water technology centre fields, during kharif 2016 – 2017 with greengram, variety (MGG – 295), College of Agriculture, PJTSAU, Rajendranagar, Hyderabad, Telangana. The initial organic carbon, N, P and K content of experimental soil was 0.35 %, 138.6 kg ha-1, 24.30 kg ha-1 and 168.70 kg ha-1 respectively. Application of biofertilizers (Rhizobium & PSB) along with inorganic fertilizers markedly influenced the nutrient concentration and soil microbial biomass carbon in mungbean crop. Among all methods application of 100 per cent RDF as drip fertigation combined with biofertigation of liquid formulation of Rhizobium and PSB registered the highest organic carbon, N, P, K content in soil and soil microbial biomass carbon were 0.54 %, 221.60 kg ha-1, 53.65 kg ha-1, 168.70 kg ha-1 and 52.40 ?g g-1 respectively.