title: 16S amplicons: control soil column
design: Genomic DNA was extracted from soil cores, in replicate, using the DNeasy PowerSoil DNA extraction kit from Qiagen (Hilden, Germany) following the manufacturer's protocol. The V4 hypervariable region of the 16S rRNA gene in both bacteria and archaea (primer pair 548F and 806R) (Kozich et al., 2013) was amplified and sequenced in duplicate for each soil core. Amplicons were sequenced on an Illumina MiSeq (San Diego, CA, USA) in the Ronholm Lab (McGill University).