Soil Sampling
Soil samples were collected to assess bacterial communities (described
below) at 6-hour intervals (00:00, 06:00, 12:00, and 18:00). We sampled
across a 24-hour sampling period at each plot once per week repeated
across 6 consecutive weeks from 14 June to 21 July 2022, resulting in
six replicates of each site-land cover-time combination (n = 6
replicates x 2 study sites x 2 land cover plots x 4 time intervals = 96
total samples).
Bacterial community soil samples: Soils were collected from the
top 10 cm at nine grid points following the Biomes of Australian Soil
Environments database protocols (Bissett et al., 2016) using a
decontaminated trowel (by using 5% bleach and DECON-90 following
protocols in Cando-Dumancela et al., 2021; 2022) and homogenised in a
sterile sample bag. From this, subsamples of 50 mL were collected and
stored on ice, then frozen at -20˚C within one hour of sampling.
Physicochemical soil samples: From the composite soil samples
taken for bacterial community analysis, 200 g was subsampled from all
12:00 samples (per plot n = 6) and sent for physicochemical
analysis. Samples were analysed by CSBP Labs (Bibra Lake, WA 6163),
quantifying levels of phosphorus, potassium, sulphur, organic carbon,
nitrate nitrogen, ammonium nitrogen, electrical conductivity, pH, and
texture using protocols described on the service provider’s website
(https://www.csbplab.com.au/tests/soil).