Application of Plant Growth-Promoting Rhizobacteria Consortia as Biofertilizers for Sustainable Cereal Production
Abstract
Sustainable crop production is increasingly threatened by declining soil fertility, climate change, excessive agrochemical use, and rising food demand. Cereal crops are major staple foods globally and require innovative strategies to improve productivity. Nigeria’s total grain production as at 2019 stood at 19.1 million tonnes, of which 11 million tonnes were corn and 6.5 million tonnes were sorghum. Among this, total imports were 5.6 million tonnes, with rice alone constituting 3.8 million tonnes, of which 3 million tonnes valued at $1.2 billion were imported from other countries. The Nigerian government recently imposed a 70% tariff and a levy on sea-imported rice, with a total import ban on land borders. Nigerian farmers are also faced with the increasing cost of fertilizer and agrochemicals. Therefore, formulating the best alternative to chemical fertilizers in terms of cost implications, environmental stability, and increased production rates will greatly enhance agricultural production in Nigeria. The Nigerian government has opened many opportunities for farmers, which need to be complemented by sustainable research outputs. Plant Growth-Promoting Rhizobacteria (PGPR) are beneficial rhizosphere bacteria that stimulate plant growth through direct and indirect mechanisms, including nitrogen fixation, phosphate solubilization, phytohormone production, siderophore secretion, pathogen suppression, and enhanced stress tolerance. Recent studies indicate that microbial consortia comprising compatible PGPR strains often outperform single-strain inoculants due to synergistic interactions and multifunctional benefits. The PGPR consortia have been reported to improve germination, root architecture, nutrient uptake, biomass accumulation, drought tolerance, grain yield, and soil health in cereal crops. The adoption of well-formulated PGPR consortia offers a sustainable pathway to enhance cereal productivity while reducing dependence on chemical fertilizers.