The impact of land-use change on the soil bacterial community in the Loess Plateau, China

The conversion of cropland to plantation is important ecological engineering in the Loess Plateau, China. Moreover, the extent of cropland abandonment and fallow is gradually increasing in this area, which probably affects the soil bacterial composition. Therefore, we applied Illumina MiSeq sequencing targeting the V3?V4 region of the 16S rRNA gene to analyze the bacterial community from different land-use types (cropland, plantation, cropland fallow and abandonment). The results showed that the plantation soil had the highest bacterial diversity. Biomarkers that strongly differentiated land-use types were found. The plantation, cropland fallow and abandonment were primarily associated with Proteobacteria, Nitrospirae, Acidobacteria, Firmicutes and Verrucomicrobia. The dominant populations from different land-use types had high similarity at the genus level, but there were still significant differences on the relative abundance of bacteria among some populations. Moreover, Pearson?s correlations indicated that soil available phosphorus (SAP), soil available K (SAK) and vegetation biomass were the important factors affecting the bacterial community. These results suggested that bacterial community structure differed among different land-use types, which was closely related to soil environmental factors, such as SAP and SAK.