Effect of salt-tolerant rice (Oryza sativa L.) cultivation on soil bacterial community and ecological function groups in coastal saline land

Salt-tolerant rice (STR) cultivation is an effective way to remediate coastal saline land (CSL). However, soil bacterial community and ecological function groups, as well as their controlling factors under STR cultivation in CSL, are still unclear. Here, we evaluated the composition, diversity, and ecological function groups of soil bacteria under different STR cultivation years in a typical CSL in eastern China. Soil bacterial communities across soil samples were dominated primarily by the phyla Proteobacteria (14.3–26.2 %), Bacteroidetes (13.5–17.3 %), Chloroflexi (13.5–17.3 %), Patescibacteria (7.1–13.1 %) and Desulfobacterota (6.6–11.0 %). STR cultivation notably decreased the relative abundance of Proteobacteria and Planctomycetota phyla, while increasing the relative abundances of the Chloroflexi, Desulfobacterota, and Crenarchaeota phyla. The richness and diversity of soil bacterial communities were significantly increased after STR cultivation. Meanwhile, a significant difference in beta diversity of soil bacterial communities was found in STR fields and uncultivated CSL. Additionally, six functional categories were identified, among which metabolism and genetic information processing were the dominant functional groups. Compared with soil bacterial community composition, the bacterial community diversity has a greater impact on bacterial ecological functions. Moreover, the composition and diversity of soil bacterial communities are profoundly driven by soil water content, electrical conductivity, total nitrogen, and total phosphorus. In summary, STR cultivation altered the soil environment and bacterial community, and their ecological function groups, thus improving soil quality and being considered an effective measure for improving CSL.