design: The following molecular ecology protocols were as described in Bisker et al. (2021): (i) DNA from 500 mg of all soil samples from the study microcosms; (ii) polymerase chain reaction and of the 16S rRNA gene; (iii) sequencing for V4 region of the bacterial 16S rRNA gene using the primers 515f (5-GTGCCAGCMGCCGCGGTAA-3) and 806r (5-GGACTACHVGGGTWTCTAAT-3) (Kozich et al., 2013; Guo et al., 2016; Pechal et al., 2018) on the Illumina MiSeq platform by NU-Omics (Northumbria University, Newcastle Upon Tyne, UK); (iv) preparation and sequencing of 16S rRNA gene sequence libraries (Kozich et al., 2013); and (v) Hill numbers (0D, 1D, 2D and ratio 1D/0D) calculations as measures of ecological diversity (Chao et al., 2010; 2014).