bacterial in long-term CC of Tibetan barley Raw sequence reads

In agroecosystems, the potential interaction between rhizosphere microbial community and cropping system is essential to crop management. However, how the specific biotic or abiotic interactions are affected by the long-term continuous cropping (CC) of Tibetan barley remains largely unknown. In this study, we investigated bacterial diversity and their metabolites composition, as well as the key taxa mediating geochemical processes of Carbon, Nitrogen, and Sulfur, in the rhizosphere soils of Tibetan barley continuous cropped in the short-term for 2 and 5 years (CCY02 and CCY05), and the long-term for 10 years (CCY10). We found the rapidly available potassium (RAK) was significantly higher in CCY10, while total nitrogen (TN), soil organic matter (SOM), and available nitrogen (AN) were significantly lower than the short-term continuous cropping years. Interestingly, we found a significant decrease in bacterial richness and phylogenetic diversity (PD) occurred along with the short-term of continuous cropping, but recovered in CCY10. Microbial community formed a less stable bacterial co-occurrence network in the short-term continuous cropping years, while resumed after long-term cropping years. Further, we determined nine key genera, which showed closely correlations with important elements cycling by QMEC and co-occurrence network analysis. Moreover, by applying LC-MS untargeted metabolomics, we observed the obvious difference in metabolites composition among different cropping years, and found that the most hub taxa Desulfuromonadales, who were frequently associated with the metabolites. Collectively, our research gave a better understanding of the effects of long-term monoculture of Tibetan barley on rhizosphere soils' bacterial community structure and function, as well as soil metabolites.