Rill erodibility as influenced by soil and land use in a small watershed of the Loess Plateau, China.

Land use can significantly affect soil properties, root systems, and tillage practices, and hence probably influence rill erodibility ( K r ) considerably. Nevertheless, there is little quantitative research on the effects of land use on K r . The objectives of this study were to evaluate the influence of land use on K r , quantify its potential influencing factors, and develop a regression model to estimate K r in a small Loess Plateau watershed. Undisturbed samples were collected from four different land uses on red Loess soil and seven different land uses on yellow Loess soil. Soil detachment capacity by overland flow was measured in a sand-glued hydraulic flume under six different shear stresses (5.59–18.31 Pa) to determine K r . The results indicated that K r was affected by soil type significantly and the average K r of yellow Loess soil was 1.5 times greater than that of red Loess soil. K r was also significantly influenced by land use. For the red Loess soil, cropped land had the maximum K r and followed by orchards, shrub land, and grassland. For the yellow Loess soil, cropped land also had the maximum K r , which was 1.74, 9.17, 11.65, 26.34, 28.88, and 42.57 times greater than those of roads, orchards, shrub land, woodland, grassland, and wasteland, respectively. K r increased with silt content, and decreased with soil cohesion, water stable aggregate, soil organic matter, and root mass density. A nonlinear regression showed that K r could be estimated well ( NSE = 0.87) by silt content, soil cohesion, water stable aggregate, and root mass density in the Loess Plateau. [ABSTRACT FROM AUTHOR]