To make a comparison of the potential of spent mycelium substrate (SMS) of Pleurotus florida as a soil conditioner compared to conventional biofertilizers in growth of Capsicum annuum, treatments used were SMS singly and with Azotobacter spp. and Glomus intraradices, to understand their interaction. Paddy straw, tea and sawdust were used as substrates in P.florida cultivation. Potted-plant experiments were conducted in triplicate, used randomized block design and standard garden soil was supplemented with 1% SMS, Azotobacter spp. and G.intraradices. Plants that used G.intraradices(T4) as biofertilizer exhibited maximum height(28.13cm), flowers(8nos.), chlorophyll(31.34mg g-1), shoot biomass(19.65gm) and uptake of leaf and fruit nitrogen (5.11 and 4.13%); plants grown on SMS+Azotobacter spp.(T3) showed maximum auxiliary buds(11nos.), soil porosity(85%), root biomass(2.54gm) and uptake of leaf and fruit potassium (2.63%); SMS (T2) used singly gave maximum soil phosphorus(0.1%), SMS+G.intraradices(T6) used together gave maximum soil nitrogen(0.32%) and a combination of SMS+Azotobacter spp.+G.intraradices(T5) exhibited highest soil carbon(1.7%) and uptake of leaf and fruit phosphorus (0.33%). Azotobacter spp.(T1) used singly gave highest fruit biomass (4.9 gm). Carbon was the main factor influencing production of leaves, leaf pigments and flowers; indicated by positive correlation (0.48, 0.64, 0.65 and 0.78) between carbon and the above factors. Nitrogen had negative correlation with height (-0.76). SMS used singly resulted in increased soil phosphorus; used with Azotobacter spp. and G.intraradices, it enhanced leaves, auxiliary buds, flowers, root biomass, soil porosity, soil carbon and nitrogen. Hence, it is more beneficial when used as a supplement to conventional fertilizers compared to being used singly.