Abstract
Background: Continuous cropping of the same crop leads to land degradation. This is also called the continuous-cropping obstacle. Currently, intercropping flue-cured tobacco with other crops can serve as an effective strategy to alleviate continuous cropping obstacles.
Results: In this study, flue-cured tobacco K326 and insectary floral plants were used as materials, and seven treatments of flue-cured tobacco monoculture (CK), flue-cured tobacco intercropped with Tagetes erecta, Vicia villosa, Fagopyrum esculentum, Lobularia maritima, Trifolium repens, and Argyranthemum frutescensrespectively, were set up to study their effects on rhizosphere soil chemical properties and composition and structure of rhizosphere soil microbial community of flue-cured tobacco. 16 S rRNA and ITS amplicons were sequenced using Illumina high throughput sequencing. Flued-cured tobacco/insectary floral plants intercropping can influence rhizosphere soil chemical properties, which also change rhizosphere microbial communities. The CK and treatment groups flue-cured tobacco rhizosphere soil microorganisms had significantly different genera, such as intercropping T. repens and A. frutescens significantly increased the number of Fusarium and intercropping T. erecta, V. villosa, L. maritima, T. repens, and A. frutescens significantly increased the number ofSphingomonas and norank_f_Gemmatimonadaceae. Additionally, intercropping T. erecta, V. villosa and L. maritima changed the rhizosphere fungal and bacterial community and composition of flue-cured tobacco and the positive correlation between flued-cured tobacco rhizosphere the genera of fungi and bacterial were greater than CK. The pathway of the carbohydrate metabolism, amino acid metabolism, and energy metabolism in rhizosphere bacteria were significantly decreased after continuous cropping. Fungal symbiotic trophic and saprophytic trophic significantly increased after intercropping V. villosa, L. maritima and plant pathogen and animal pathogen were increased afterintercropping T. repens and A. frutescens. Additionally, bacterial and fungal communities significantly correlated with soil chemical properties, respectively.
Conclusion: Based on the results, we may provide new insights into improving barriers to continuous cropping of flue-cured tobacco via intercropping approach to regulate the rhizosphere environment, which would allow us to facilitate translation to more effective measures.