| To examine the effects of different planting years on soil nutrition and microbial community, the Illumina sequencing method was used to investigate the diversity and structure of bacterial community in the rhizosphere soil of 3, 4, and 7-year-old Elymus sibiricus (Y3, Y4, and Y7). Results showed that the pH of the rhizosphere soil increased from 7.95 to 8.03 while the total nitrogen (TN), available nitrogen (AN), and available phosphorus (AP) were gradually decreased as the planting years increased. Compared to Y3, TN, AN, and AP in the rhizosphere soil of Y4 decreased 21.9%, 12.0%, and 32.0%, while which they decreased 34.5%, 24.2%, and 38.9% with Y7, respectively. The Chao1 and Shannon indices were also degraded with planting years, while the Chao1 indices of Y3, Y4, and Y7 were 2605.42, 2518.46, and 2483.89, and the Shannon indices were 9.79, 9.65, and 9.62, respectively. Clustering analysis showed that the bacterial communities of rhizosphere soil in 3 and 4-year-old Elymus sibiricus were similar to each other. The bacterial communities’ dominant phyla of all soil samples were Proteobacteria, Actinobacteria, and Acidobacteria. Meanwhile, Norank_c_Subgroup_6, Sphingomonas, Norank_ f_Gemmatimonadaceae, Blastococcus, and RB41 were the dominant genera. Correlation analysis showed that MND1 and Gaiella were negatively correlated with TN, TP, TK, AP, and AK, and were positively correlated with SOM. While Bacillus, RB41, and Norank_ f _67-14 were positively correlated with pH (P<0.001). |