3.6. Effects of soil chemical properties on abundant phyla
Monte Carlo tests based on the selected soil chemical properties
and top 20 bacterial or fungal genera abundance revealed that the
selected soil chemical properties were significantly correlated with
the variation of top 20 bacterial genera (P = 0.01) but was not
significantly correlated with the variation of top 20 fungal genera
(P = 0.39). The RDA analysis showed that the
first and second RDA
components were able to explain 75.2% of the total bacterial
variation (Fig. 6). The
first component (RDA1), explaining 56.9% of
the total variation of bacterial genera, separated the CF control
from the LBIO and HBIO treatments, and the second component
(RDA2), explaining 18.3% of the total variation of bacterial genera,
separated the HBIO treatment from the LBIO treatment. As shown
by their close grouping and the vectors, the top 20 bacterial genera
in the CF control were dominated by Gp4, Gp6, Terrimonas and
Pasteuria, and related to the soil C/N ratio and the available K
content, while the top 20 bacterial genera in the HBIO treatment
were dominated by Bacillus, Spartobacteria_genera and TM7_genera,
and related to soil pH, TOC, TON, NH4-N, NO3-N and the
available P content