Impacts of Cropping Systems and Long-Term Tillage on Soil Microbial Population Levels and Community Composition in Dryland Agricultural Setting
Table 2
Pairwise comparison of treatments and comparison of phylogenetic groups between treatments. (A) Parsimony test results between treatments. (B) Relative abundances of bacterial phyla detected in 16S rRNA gene clone libraries derived from soil under different long-term tillage and rotation treatments.
Phylogenetic group
Treatmenta
CT-CW
CT-RW
NT-CW
NT-RW
(A) Treatment
CT-CW
—
CT-RW
<0.001
—
NT-CW
0.083
0.109
—
NT-RW
0.007
0.028
0.086
—
(B) Phylogenetic group
%
Acidobacteria
44.1
43.6
48.0
46.9
Actinobacteria
5.9
9.4*
3.6
7.5
Bacteroidetes
6.4
5.6
4.0
3.1
Chloroflexi
nd
nd
nd
0.4
Cyanobacteria
3.0
0.4*
4.4
1.3
Deinococcus-Thermus
nd
nd
nd
0.4
Firmicutes
3.8
2.1
0.9*
1.3
Gemmatimonadetes
2.5
1.3
1.3
0.9
Nitrospira
0.4
nd
nd
nd
OP10
0.8
nd
nd
0.4
OP11
nd
0.4
nd
nd
Planctomycetes
4.7
4.3
4.9
5.3
Proteobacteria
22.9
27.4
24.4
22.4
α-Proteobacteria
5.5
10.3
5.3
6.1
β-Proteobacteria
8.5
8.1
10.7
8.8
γ-Proteobacteria
4.7
3.0
4.4
2.6
δ-Proteobacteria
4.2
6.0
4.0
4.8
TM7
0.4
nd
nd
nd
Verrucomicrobia
1.7
1.3
1.3
1.8
WS3
0.4
nd
nd
nd
Unclassified bacteria
3.0
4.3
7.1
8.3
aNT: no tillage; CT: conventional tillage; CW: continuous wheat; RW: sorghum-wheat-soybean rotation. nd indicates that the phylogenetic group was not detected.
*Significantly different from CT-CW at .
