A field experiment was undertaken at College of Agriculture, Vellayani during June to December 2019, to assess the efficacy of liquid consortium biofertilizer, Plant Growth Promoting Rhizobacteria (PGPR) Mix - I in cassava and to examine the changes in soil chemical and biological properties with the application. The treatment combinations included four levels of biofertilizer [PGPR Mix - I liquid (L) @ 2 %, PGPR Mix - I liquid (L) @ 5 %, PGPR Mix - I powder (P) formulation @ 10g of 2 % mixture per plant, without biofertilizer] and three levels of nutrients, with 50: 50: 100 kg NPK/ha as the standard dose of nutrients (SDN), [50 % SDN, 75 % SDN, 100 % SDN]. The 4 × 3 factorial experiment was laid out in randomized block design with three replications. The results of the study revealed that the liquid biofertilizer consortium at 5 per cent + 75 percent SDN (37.5: 37.5: 75 kg NPK /ha) recorded significantly superior yield attributes in cassava and improved the soil organic C, available K status and microbial count.