TABLE 1.

Relative abundances of bacterial phyla among locations, years, cropping systems, and root proximities^a

Parameter	% abundance (mean ± SD)
	Acidobacteria	Actinobacteria	Bacteroidetes	Firmicutes	Planctomycetes	Proteobacteria	Verrucomicrobia
Location
Colfax	13 ± 0.04 a	30.3 ± 0.11 a	12.6 ± 0.07 a	0.69 ± 0.01 a	3.5 ± 0.03 a	31.8 ± 0.09 a	3 ± 0.01 a
Lamont	13 ± 0.05 ab	27 ± 0.13 b	13.2 ± 0.12 a	1.1 ± 0.02 a	3.8 ± 0.05 a	33 ± 0.12 a	3.4 ± 0.01 a
Ritzville	11.7 ± 0.09 b	27.7 ± 0.13 a	13.7 ± 0.14 a	0.46 ± 0.004 b	2.6 ± 0.02 a	38.7 ± 0.16 b	2.1 ± 0.02 b
Genesee	11.2 ± 0.05 b	34.4 ± 0.12 c	9.9 ± 0.11 b	5.4 ± 0.13 c	2.2 ± 0.01 a	31.9 ± 0.13 a	1.6 ± 0.02 b
Year
2015	13.4 ± 0.04	26 ± 0.07	15.4 ± 0.07	3 ± 0.06	4.5 ± 0.02	30.9 ± 0.07	2.2 ± 0.02
2016	11.5 ± 0.02	32.9 ± 0.06	10.1 ± 0.03	0.9 ± 0.01	2 ± 0.01	35.7 ± 0.05	2.8 ± 0.01
Land use history
No-till	11 ± 0.03 a	29.1 ± 0.07 a	12.1 ± 0.06 a	1 ± 0.01 a	2.8 ± 0.02 a	36.8 ± 0.08 a	2.2 ± 0.01 a
CRP	13.6 ± 0.03 b	28.6 ± 0.07 a	12.7 ± 0.06 a	2.8 ± 0.05 b	3.2 ± 0.02 a	32.4 ± 0.06 b	2.7 ± 0.01 b
Root proximity
Bulk	14.2 ± 0.03 a	33.4 ± 0.07 a	9.1 ± 0.03 a	1.9 ± 0.03 a	3.5 ± 0.01 a	30.5 ± 0.05 a	2.6 ± 0.01 a
Rhizosphere	10.5 ± 0.03 b	26.6 ± 0.06 b	15.5 ± 0.05 b	1.7 ± 0.03 a	2.6 ± 0.02 b	36.7 ± 0.07 b	2.5 ± 0.01 a

^aSignificant differences, indicated by different letters, were determined using Kruskal-Wallis tests. Differences were considered significant if FDR-adjusted P values were <0.05. Multiple comparisons were performed using Dunn’s test.