Bacterial 16S rRNA gene amplicon sequencing from cropland and forest soils across China

This project contains bacterial 16S rRNA gene amplicon sequencing data from soils collected in cropland and adjacent forest ecosystems (coniferous and broadleaved forests) across eight sites in China. Sampling was conducted between August and September 2023. At each site, paired cropland and forest plots were established, and soils were collected at depths of 0-20 cm and 60-80 cm. After quality control, a total of 144 soil samples were obtained, with roots, litter, and stones removed before processing.DNA was extracted using the TGuide S96 Magnetic Soil/Stool DNA Kit (Tiangen Biotech, Beijing, China). The V3-V4 region of the bacterial 16S rRNA gene was amplified with primers 338F (5'-ACTCCTACGGGAGGCAGCA-3') and 806R (5'-GGACTACHVGGGTWTCTAAT-3'). PCR products were purified, libraries were prepared using the NEBNext Ultra DNA Library Prep Kit, and sequencing was performed on an Illumina NovaSeq 6000 platform.The raw sequencing reads were demultiplexed, quality filtered, and processed in QIIME2 to generate amplicon sequence variants (ASVs). Taxonomic annotation was conducted against the Silva database. These data provide insights into bacterial community structure in cropland and forest soils with contrasting soil organic carbon levels across a broad climatic gradient in China.