Spatial Variations in Concentration, Compositions of Glomalin Related Soil Protein in Poplar Plantations in Northeastern China, and Possible Relations with Soil Physicochemical Properties

Table 2

Two-way ANOVA results on spatial (site, soil layer) variations of different soil physicochemical properties in poplar shelterbelt forests in Songnen Plain.

Index	pH value	EC	Bulk density	Soil moisture
Site
𝐹	55.21	2.08	29.76	111.05
𝑃 value	0.000	0.068	0.000	0.000
Soil layer
𝐹	7.13	3.90	7.62	9.34
𝑃 value	0.000	0.004	0.000	0.000
Interaction
𝐹	0.26	0.56	1.55	1.22
𝑃 value	1.000	0.937	0.062	0.232
Site-related differences (mean and their statistical significance)
Dumeng	8.49^a	105.7^ab	1.51^a	5^d
Fuyu	8.46^a	152.1^a	1.40^bc	17^a
Lanling	7.68^b	122.6^ab	1.43^b	9^c
Mingshui	7.44^b	80.9^b	1.32^d	16^a
Zhaodong	8.51^a	114.9^ab	1.39^bc	13^b
Zhaozhou	8.53^a	139.5^ab	1.38^c	9^c
Largest/lowest ratio	1.15	1.88	1.14	1.89
Soil layer-related differences (mean and their statistical significance)
0–20 cm	8.08^ab	105.2^b	1.37^c	13^a
20–40 cm	8.00^b	173.7^a	1.39^bc	12^ab
40–60 cm	8.15^ab	114.4^ab	1.41^abc	11^ab
60–80 cm	8.32^a	110.2^b	1.43^ab	10^b
80–100 cm	8.38^a	92.9^b	1.43^a	10^b
Largest/lowest ratio	1.05	1.87	1.04	1.30
Mean of pooled data	8.19	119.28	1.41	11

Note: Different lowercases indicate the related differences between different soil layers or between different sites were statistically significant (𝑃<0.05).