Short-term effects of cover grass intensity on soil microbial
communities in an apple orchard
Abstract
Soil microbiota play an important and diverse roles in horticultural
crop nutrition or productivity. However, the soil microbial community
composition and the relationships within the taxa in the microbial
community populations after cover grass treatments in apple orchards are
not well understood. We analysed the microbial community diversity,
composition and microbial network of an apple orchard after covering
with native wild grasses at different intensities for 2 years in the
Loess Plateau, China. The cover grass intensities were 0%, 20%, 40%,
60% and 80%. Soil microbial community diversity was not obviously
change by cover grass in the apple orchard. Cover grass altered the
microbial bacterial community compositions, their changes exhibited
significant differences at the phylum level that were caused by the
Proteobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes,
Nitrospirae. However, low-intensity (20%) and moderate-intensity (40%)
treatments were the only cover grass intensities that altered the soil
fungal community composition; but their changes did not exhibit
significant differences at the phylum level. The positive links among
the bacterial taxa decreased with the increasing cover intensity,
primarily among Proteobacteria, Acidobacteria, Actinobacteria,
Chloroflexi and Gemmatimonadetes. Although cover grass increased the
positive links between fungal taxa, these taxa were reduced with the
increasing cover intensity. Here we demonstrate that cover grass changed
the soil microbial community, and the changes may be attributed to the
given phyla in the bacterial community; furthermore, the antagonistic
effect between the soil bacterial and fungal communities was
significantly increased by higher coverage than by lower coverage.