Abstract
The present investigation was undertaken to assess the feasibility and compatibility of different biofertilizers like Rhizobium, Azotobacter, Azospirillum, Pseudomonas and Bacillus as co-cultured multiple inoculant. The microbe-microbe interaction under cultural conditions, in charcoal-based carrier and with pigeonpea and mungbean plants was determined. Under cultural conditions, co-inoculation of Azotobacter, Bacillus, Pseudomonas and Rhizobium resulted in reduced growth of Rhizobium. A co-culture multiple inoculant in sterilized fine wood charcoal powder (200 g) of Azotobacter, Azospirillum, Bacillus and Pseudomonas containing more than 2×108 cells g−1 carrier was possible. However, the number of rhizobia reduced to less than 2×108 cells g−1 carrier, when co-cultured with Rhizobium. Inoculation of pigeonpea and mungbean seeds with multiple co-inoculant produced maximum nodule biomass, plant biomass and total soil N in case of pigeonpea and mungbean hosts. However, no beneficial effect of co-cultured multiple inoculants on nodule occupancy of pigeonpea or mungbean was observed.