Characteristics of soil physical properties and spatial distribution of soil erosion on ridge-slope farmland in the black soil areas of Northeast China

Abstract: To explore the spatial distribution characteristics of soil physical properties and soil erosion in sloping farmland with ridges in the black soil areas of northeast China, the slope farmland with ridges built with woven bags (RW) along the contour lines was selected as the research object, and the slope farmland was selected as a control (CK). Soil samples were collected from both RW and CK at uniform spatial intervals to measure key indicators of soil properties in the surface layer (0-15 cm), including soil water holding capacity, soil structure, and annual average soil loss (A). The results showed that: (i) RW exhibited a significantly higher overall field water-holding capacity compared to CK, with soil moisture characteristics more evenly distributed spatially. Soil bulk weight, fractal dimension and soil aggregate destruction in RW were reduced by 1.09%, 0.65% and 4.61%, respectively, compared to CK. Additionally, soil total porosity, capillary porosity, mean weight diameter (MWD), and geometric mean diameter (GWD) were more evenly distributed spatially in RW. (ii) On the up-slope, soil water content and DR_>0.25 in the RW had higher increase than those of the CK. On the mid-slope, soil field water holding capacity, capillary porosity, MWD and GWD in the RW had a higher increase than those in the CK. On the down-slope, RW had a 7.67%-10.79% increase in soil water content, saturated water holding capacity, field water holding capacity, and capillary water holding capacity compared to CK, with total soil porosity and soil capillary porosity increasing by 2.84% and 15.51%, respectively. (iii) Annual average soil loss (A) of RW was reduced by 61.85%~99.64% compared to CK, based on the China Soil Loss Equation (CSLE). (vi) Soil water-holding capacity and soil structure characteristics of the RW showed benefits compared to the CK, with the benefits ranging from 1.01 to 1.09, while the benefit of A reached 2.46. This study is significant for understanding the spatial distribution of soil erosion on slope farmland in black soil areas and for the effective application of soil and water conservation measures.