Effect of indigenous mineral availing microbial consortia and cattle manure combination for growth of maize (Zea mays L.)

Plant growth promoting bacterial strains were used as bioinoculants on cereal crops to improve plant growth and plant productivity. Crop responses to inoculation are complex because bacteria are not compatible with each other. Therefore, it is necessary to increase our understanding of the microbial ecology of crop rhizosphere under various agricultural techniques. In tropical agriculture, cattle manure is used as an organic fertilizer to increase soil fertility, however use of microbes as consortium have found as sustainable method for the enhancement of crops productivity. The purpose of this study was to evaluate the effects of three potential plant growth-promoting rhizospheric and endophytic bacterial strains EU-C3ST.R1, IARI-JR-44, and IARI-S-45 and organic fertilizers (cattle manure) individually and as consortia on maize (Zea mays L.) under both in-vitro and in-vivo conditions. A total of 123 bacterial strains were sorted out and screened for nitrogen fixation, phosphorus, and potassium solubilization. The potential N₂-fixing; P and K solubilizing bacterial strains were identified using 16 S rRNA gene sequencing as Pseudomonas sp. EU-C3ST.R1, Micrococcus indicus IARI-JR-44, and Bacillus horikoshii IARI-S-45 respectively. The inoculation of these three strains on maize as microbial consortium and individual inoculum significantly increased the growth characteristic including height and biomass of the plants, as well as physiological characteristics i.e., chlorophyll, carotenoids, flavonoids, phenolics, and total soluble sugar content of the plant with respect to chemical fertilizers, cattle manure, and untreated control plant. The consortia were found to be more effective with respect to individual inoculants, cattle manure, and uninoculated control plants, so it can be utilized as biofertilizers for inoculation of cereal crops growing in hilly regions.