Restoration of continuous cropping obstacles by microbial inoculants and mineral amendment in flue-cured tobacco

Continuous cropping obstacles (CCOs) impair soil health and reduce crop yields, posing a significant challenge to agricultural sustainability. Tobacco is a vital economic crop worldwide. For shortage of arable land, tobacco suffers economic losses attributed to CCOs. To address tobacco CCOs, we conducted a 2-year field experiment utilizing microbial inoculants coupled with a mineral soil amendment (tobermorite). Compared to the control, the combined application of microbial inoculants ( Bacillus velezensis K01 and Streptomyces xylanolyticus B75) with tobermorite significantly increased yield by 15.8% and economic value by 32.9%; reduced the disease index by 73.8% of black root rot caused by Fusarium spp.; and enhanced the absorption of mineral nutrients, increasing the leaf contents of boron (B), iron (Fe), and magnesium (Mg) by 45.0%, 65.7%, and 40.1%, respectively. Microbial inoculants and mineral soil amendment modulated the soil bacterial and fungal community structures, increasing bacterial and fungal richness, reducing the abundance of pathogens such as Fusarium , enriching beneficial native bacterial genera such as Pseudomonas , and increasing the number of nodes and edges in the fungal network. Path analysis revealed that fungal community abundance was a critical positive driver of flue-cured tobacco yield. • The combined application of microbial inoculants and tobermorite increased tobacco production while suppressing diseases. • Fungal community restructuring is a key factor in mitigating tobacco continuous cropping obstacles. • Fungal community abundance and plant biomass positively influenced yield, while the disease index had a negative influence.