Temporal recovery of soil biological activity and diversity after 915-MHz microwave treatments (Illumina MiSeq, 16S rRNA V4-V5)

Treating soil by microwaves to control plants invasiveness is an alternative method to chemical treatments that could however impact untargeted soil organisms. Two 915 MHz microwave treatments combining power and duration (2 kW-8 min and 4 kW-4 min) were applied on an alluvial soil sampled from a grassland and their effects were surveyed for four weeks. Soil DNA content, hydrolysis activity and abundance and diversity of heterotrophic organisms (bacteria, fungi and nematodes) were monitored after treatments over 26 days under standardized conditions.Bacterial diversity was analyzed by using a metagenomics approach applying MiSeq Illumina sequencing. The 16S rRNA V4-V5 region of DNA was amplified with the forward PCR1_515F (GTGYCAGCMGCCGCGGTA) and reverse PCR1_928R (CCCCGYCAATTCMTTTRAGT) primers.