Applied and Environmental Soil Science

Research Article

Magnitude of Annual Soil Loss from a Hilly Cultivated Slope in Northern Vietnam and Evaluation of Factors Controlling Water Erosion

Table 5

Significant differences in the mean daily soil loss between plots 1 to 12, between groups A to D and between 1st to 3rd years analyzed by either the Kruskal-Wallis test or the t-test.


Effect examined	Group/year	Plots/groups/years examined for the difference		Soil loss
Effect examined	Group/year	Plots/groups/years examined for the difference		-value	Plots/groups/years in significant combinations

Land-cover	1	1, 2, 3	31	.117
	1	4, 5, 6	31	.0001^**	4–6, 5-6
	3	4, 5, 6	25	<.0001^**	4-5, 4–6
	1	7, 8, 9	22	.093
	2	7, 8, 9	22	.159
	1	10, 11, 12	22	.855
	2	10, 11, 12	22	.554
	3	10, 11, 12	25	<.0001^**	10–12 11-12

Slope gradient	1	A, B, C, D	93⁽²⁾, 66 ⁽³⁾	<.0001^**	A-D, B-C, B-D
Slope gradient	3⁽¹⁾	B, D	75	.221

	B⁽¹⁾	1 , 3	93 ⁽⁴⁾, 75 ⁽⁶⁾	.387
Seasonal rainfall	C⁽¹⁾	1 , 2	66	<.0001^**
	D	1 , 2 , 3	66 ^{(4, 5)}, 75 ⁽⁶⁾	<.0001^**	1-2, 1-2, 2-3

: number of observations for each group/year.
^**: significance at 1% level.
⁽¹⁾: analyzed by the -test, and others were by the Kruscal-Wallis test.
⁽²⁾ and ⁽³⁾: numbers for groups A and B and for groups C and D, respectively.
^{(4, 5)} and ⁽⁶⁾: numbers for 2000, 2002, and 2003, respectively.