Harnessing the potential of zinc and phosphorus solubilizing bioinoculants for sustainable rice growth under diverse agroecological conditions

Abstract The rhizosphere, is dynamic and replete with diverse microorganisms, creating a commendatory niche. The rice rhizosphere is a unique anaerobic habitat that enriches the specific microbiota. The current study explored the rhizosphere isolates for minerals solubilization, Indole Acetic acid, siderophore production, and plant growth promotion under pot and field conditions. The in vitro analysis revealed that the isolates could solubilize phosphorus, zinc, silica, and potassium, with a comprehensive range of 4.86 to 21.30 mm halo zone. The IAA production reported in Azospirillum lipoferum, Beijerinckia indica, and Azotobacter chroococcum was 81.56, 68.75, and 47.15 µg/50 ml of broth. The efficient isolates were identified as Pseudomonas aeuruginosa, Priestia/Bacillus aryabhattai, Bacillus/Priestia xanthoxyli, and Pseudomonas sp. based on the 16 S rRNA analysis. Later, a consortium of efficient isolates was formulated in the liquid, sodium alginate, lignite, and peat evaluated for quality, where the liquid formulations had the maximum populations of 8.3 × 1010 CFU/ ml. Three consortia (Paddy Microbial Consortium 1, 2, and 3) were formulated and were evaluated in the pot culture trail, where the PMC 2 (Azospirillum lipoferum, Pseudomonas aeuruginosa, Priestia aryabhattai Pseudomonas sp., Priestia xanthoxyli) increased the dry biomass (89.72 g/plant), soil enzymes like dehydrogenase (89.7 µ TPF g− 1 of soil d− 1) and phosphatase (30.47 µg PNP g− 1 soil h− 1) and LAI (1.31) when compared with other consortia. In the field study, the liquid formulation enhanced nitrogen, phosphorus, potassium, and zinc in the plant biomass by 59.53, 71.42, 54.20, and 29.01%, respectively.