Effects of hedgerow on soil fractal characteristics and erodibility of sloping farmland in the purple soil area of Sichuan, China

This paper studied effects of vetiver hedgerow and leucaena leucocephala hedgerow on fractal characteristics and erodibility of the purple soil. It took fractal dimension of PSD (particle-size distribution) to describe soil fractal characteristics, and EPIC (erosion-productivity impact calculator) to calculate values of soil erodibility factor K. Results showed that:(1) hedgerows affected spatial distributions of soil particles as small ones reduced in CK (check) plots, but increased in hedgerow plots.(2) Variations of PSD fractal dimension had negative linear correlation with variations of sand content with correlation coefficient of −0.828, but had positive linear correlations with variations of silt content and clay content with correlation coefficients of 0.638, 0.898.(3) Values of K decreased in 10° plots with hedgerows, especially with vetiver hedgerows.(4) Variations of K had significant positive correlations with variations of sand content and dispersion coefficient of micro-aggregate (particle size < 0.002mm), and their correlation coefficients were 0.980 and 0.836. Variations of K had negative correlation with variations of silt content, clay content, organic carbon content and aggregation rate, and their correlation coefficients were −0.925, −0.833, −0.787 and −0.716. (5) Vetiver is more suitable than Leucaena leucocephala for popularization and application on control of the purple soil erosion.