Table 1. Soil physical properties of shifting sand and shelterbelt soil after shelterbelt has been set up for 7 years.

Physical properties	Soil Bulk Density (g cm3-)	Clay Content (%)	Silt Content (%)	Sand Content (%)	Soil aggregate sizes (%)					Soil aggregate stability
					>5 mm	5~2 mm	2~1 mm	1~0.5 mm	0.5~0.25 mm	>0.25 mm	MWD (mm)	GMD (mm)
Shifting sand (CK)	1.5±0.03a	0.27±0.01	12.35±0.04	87.48±1.25	0b	0b	0b	0b	0b	0b	0.13b	0.13b
Shelterbelt soil	1.3±0.007b	0.67±0.01a	19.9±0.37a	79.69±7.25b	4.08±0.09a	1.25±0.02a	0.33±0.01a	0.25±0.01a	0.18±0.01a	6.08±0.11a	0.48±0.01a	0.16±0.001a

Note: MWD presents the mean weight diameter, GMD presents geometric mean diameter and CK presents the shifting sand, the different letters give significant difference at P = 0.05.