Microbial organic fertilizer improves soil microbial community and promotes tobacco growth

Continuous cropping obstacles pose a significant threat to sustainable tobacco (Nicotiana tabacum L.) production. To mitigate these obstacles and soil degradation in tobacco cultivation, thereby improving economic returns, this study implemented field experiments with different fertilization regimes. We systematically investigated changes in soil chemical properties, rhizosphere microbial community structure, tobacco growth parameters, chemical composition of flue-cured tobacco, and yield. The effects of microbial organic fertilizer (MOF) on soil improvement were comprehensively evaluated. Compared to conventional fertilization (control), MOF application resulted in a soil pH increase of 0.37 units at the bunching stage and 0.49 units after topping, along with a 36.42% (p < 0.001) elevation in total phosphorus content. Rhizosphere bacterial α-diversity (Shannon index) increased by 6.19% (p < 0.001), with higher relative abundance of beneficial microorganisms. Meanwhile, MOF application significantly increased the yield of flue-cured tobacco by 20.40% (p < 0.01), reaching 2128.2 kg/hm² compared with 1767.6 kg/hm² in the conventional fertilization control. These improvements collectively enhanced tobacco growth and flue-cured tobacco quality. Overall, MOF technology effectively improves soil chemistry and microbial community structure, promotes tobacco growth, and enhances flue-cured tobacco quality compared to conventional fertilization.