Long-term soil redistribution and mollic epipedon thickness reveal distinct dimensions of soil degradation across cultivated Mollisol slopes

This dataset contains data on soil erosion-deposition, mollic epipedon thickness, soil nutrients, aggregate stability, and particle-size composition collected from cultivated slopes in Qiqihar and Qian’an on the Songnen Plain of Northeast China. Parallel transects were established on straight, convex, and concave slopes, with sampling locations distributed along the downslope direction. Sample_ID identifies each sampling location; Site denotes the study area; Shape denotes slope shape; Transect identifies the sampling transect; Width_m and Distance_m describe the cross-slope and downslope spatial positions of each sampling location, respectively; slope gradient (°) represents the local slope gradient; Slope_length_m represents total slope length; SER_t_km2_a represents the long-term soil erosion-deposition rate estimated using the ¹³⁷Cs tracing technique (t km⁻² yr⁻¹); ME_cm represents mollic epipedon (ME) thickness (cm); SOM_g_kg and TN_g_kg represent soil organic matter and total nitrogen contents (g kg⁻¹), respectively; AP_mg_kg, AK_mg_kg, and AN_mg_kg represent available phosphorus, available potassium, and available nitrogen contents (mg kg⁻¹), respectively; MWD_mm represents the mean weight diameter of water-stable aggregates (mm); and Sand_pct, Silt_pct, and Clay_pct represent the proportions of sand, silt, and clay (%), respectively. The dataset was compiled to investigate spatial relationships among long-term soil redistribution, remaining mollic epipedon thickness, and soil functional attributes across different slope shapes and slope positions.