Effects of tobacco plant residue return on rhizosphere soil microbial community

Based on the recycling principle, returning of tobacco crop residues into the field is a common agronomic practice. However, comprehensive knowledge about the effects of tobacco plant residue return on the rhizosphere soil microbial community is very limited. After tobacco crop residue returning into the potted soil, 16S ribosomal RNA (rRNA) and internal transcribed spacer (ITS) amplicon sequencing were employed to investigate the bacterial and fungal communities, respectively, from the tobacco rhizosphere soils. The results showed that tobacco residue returning increased the diversity of microbial communities (bacteria and fungi) and changed the species composition. It further increased the relative abundance of beneficial microorganisms. After tobacco residue returning, the structure of the rhizosphere soil microbial community network was found more complex with strong interactions among microbial species. In addition, the keystone species of bacterial and fungal communities associated with tobacco rhizosphere soil were altered. This had exerted a driving force to the beneficial bacteria such as Sphiningomonas and Psathyrella to the keystone microorganisms which played important roles in microbial species interaction. Tobacco residue return into soil showed significant effects on the microbial diversity, community composition, network structure, keystone microorganisms, and ecosystem functions of tobacco rhizosphere soils. This study provides a scientific basis for the improvement of tobacco field ecosystem functioning and ensuring soil health.