To investigate the effects of intercropping sweet potato with tobacco on the tobacco rhizosphere soil microbial diversity and to provide a theoretical basis for the promotion of this cropping pattern, Illumina MiSeq high-throughput sequencing technology was employed to compare the microbial diversity and community composition in the tobacco rhizosphere soil under two treatments: tobacco-sweet potato intercropping and tobacco monoculture. The results showed that, compared with tobacco monoculture, intercropping with sweet potato reduced the α-diversity of the fungal community in the rhizosphere soil. At the bacterial phylum level, the relative abundances of Acidobacteriota and Firmicutes increased by 3.29 and 1.82 percentage points, respectively, under intercropping, while those of Actinobacteriota, Proteobacteria, and Chloroflexi decreased by 2.70, 1.16, and 1.82 percentage points, respectively. At the fungal phylum level, the relative abundances of Mortierellomycota, Basidiomycota, and unclassified_k_Fungi increased by 3.01, 1.94, and 0.91 percentage points, respectively, whereas that of Ascomycota decreased by 5.92 percentage points. At the bacterial genus level, the relative abundances of norank_f_Vicinamibacteraceae, norank_f_norank_o_Vicinamibacterales, Bacillus, RB41, and norank_f_norank_o_Gaiellales increased by 0.67, 0.86, 1.47, 0.67, and 0.15 percentage points, respectively, under intercropping. In contrast, the relative abundances of norank_f_JG30-KF-CM45, norank_f_67-14, norank_f_Gemmatimonadaceae, norank_f_norank_o_ norank_c_KD4-96, Blastococcus, Streptomyces, and Solirubrobacter decreased by 0.43, 0.01, 0.37, 0.21, 0.31, 0.25, and 0.15 percentage points, respectively. Correlation analysis indicated that soil pH value significantly influenced the rhizosphere microbial community, exerting notable effects on Firmicutes, Chloroflexi, Ascomycota, and Mortierellomycota. This study provides a theoretical foundation for the promotion and application of the tobacco-sweet potato intercropping pattern.
