With indoor experiment and field test

soil physical and chemical properties

soil disintegration rate and related influential factors of sloping land were determined. The formula calculation method of EPIC (ero-sion productivity impact calculator) was applied to investigate the erodibility factor K of the soil in sloping lands in northeastern upland region of China. The results indicate that soil bulk density increased in an as-cending order of soil depth as 0-5 cm＜20-25 cm＜40-45 cm. The soil of lower slope had smaller bulk density than that of upper slope. Similarly

the soil from gentle slope(7°) had smaller bulk density than that from steeper slope(10°). The organic matter contents showed an exactly opposite trend to bulk density. The median diameter of grain sizes did not show clear trend. The soil disintegration rates gradually increased with soil depth and correlated closely with soil bulk densities and organic matter contents.

soil disintegration rate decreased with increase of organic matter content and decrease of soil bulk density. The soil from upper slope often had higher soil disintegration rate than that from lower slope

and the soil from gentle slope(7°) had smaller soil disintegration rate than that from steeper slope(10°). The calculated soil erodibility K varied be-tween 0.20 -0.40

indicating weak anti-erodibility. Therefore

water and soil conservation should be strengthened in the research area.