Response of Fractal Analysis to Soil Quality Succession in Long-Term Compound Soil Improvement of Mu Us Sandy Land, China

Table 2

Relationships between the FD of compound soil particles in different proportions and the content of each grain fraction.

Soft rock : sand	D and sand (0.05–2 mm) X1	D and silt (0.002–0.05 mm) X2	D and clay (<0.002 mm) X3
1 : 1	D = −0.003X11 + 2.764	D = 0.003X21 + 2.431	D = 0.029X31 + 2.372
	R^2 = 0.574	R^2 = 0.458	R^2 = 0.963
1 : 2	D = −0.007X12 + 3.019	D = 0.008X22 + 2.318	D = 0.038X32 + 2.326
	R^2 = 0.894	R^2 = 0.851	R^2 = 0.952
1 : 5	D = −0.006X15 + 2.934	D = 0.006X25 + 2.333	D = 0.067X35 + 2.230
	R^2 = 0.531	R^2 = 0.438	R^2 = 0.965

²D: FD value; X_1i: sand content in different proportions of the compound soil; X_2i: silty content in different proportions of the compound soil; and X_3i: Clay content in different proportions of the compound soil.