design: Total DNA from soil subsamples was isolated using DNeasy PowerSoil (Qiagen, Germany), variable 16S rRNA regions were amplified with primers 341F 5CCTAYGGGRBGCASCAG3 and 806R 5GGACTACNNGGGTATCTAAT3 for V3V4 region or with primers 515F 5GTGCCAGCMGCCGCGGTAA3 and 907R 5CCGTCAATTCCTTTGAGTTT3 for V4V293