Synergistic Effects of Bacterium ZM12 and Vermicompost on Groundnut Yield, Quality, and Nutrient Uptake

Peanut cultivation in nutrient-poor soils often relies heavily on chemical fertilizers, leading to soil degradation, reduced productivity, and lower profitability for farmers. To address this issue, a sustainable alternative combining organic amendments and beneficial microbes was evaluated. The research objective is to assess the influences of vermicompost addition and inoculant with Bacterium strain ZM12 on the growth, yield, and quality of peanuts. Bacterium strain ZM12 was isolated on YMA medium and identified using 16S rRNA gene sequencing. Field research was conducted using a factorial design with two factors: (i) inoculation vs. non-inoculation with strain ZM12 and (ii) three rates of vermicompost (0, 5, and 10 t ha-1), resulting in six treatments with four replications. The combined application of 10 t ha-1 vermicompost and ZM12 inoculation significantly enhanced peanut protein content and growth performance. Peanut yield increased by 38.4% with 10 t ha-1 vermicompost compared to the control (0 t ha-1), and ZM12 inoculation alone improved yield by 12.9% compared to non-inoculated plots. These improvements were attributed not only to biological nitrogen fixation but also to the plant growth-promoting effects of strain ZM12. The study demonstrates an effective strategy for improving peanut productivity and soil fertility while reducing dependence on chemical fertilizers. However, future work should include the isolation and testing of additional beneficial microbial strains to further enhance the sustainability of this approach.