Simulated Rainfall Reveals Divergent Runoff–Sediment Dynamics and Soil Property of Aeolian Sandy Soil, Mollisol, and Chernozem in Northeast China

ABSTRACT Water erosion threatens soil ecosystem services globally. In Northeast China, the differential impacts of rainfall on runoff–sediment dynamics and soil physicochemical properties across three major erosion‐prone agricultural soils, namely aeolian sandy soil, mollisol, and chernozem, remain poorly understood. To address this, rainfall simulation experiments were conducted at rainfall intensities of 0, 50, and 100 mm h −1 to assess runoff, sediment yield, and soil properties in the three soil types. Under 100 mm h −1 rainfall, mollisol exhibited the highest total sediment yield, whereas aeolian sandy soil had the lowest. In the sediment, clay, C, and N content in aeolian sandy soil and chernozem increased significantly under 100 mm h −1 rainfall relative to 50 mm h −1 . In the soil flume, rainfall intensity significantly increased soil shear strength and compaction ( p < 0.05). Relative to the no‐rainfall treatment, clay content decreased by 14.7%–37.2% in chernozem and by 6.7%–8.3% in mollisol under 50 and 100 mm h −1 rainfall. The proportion of water‐stable aggregates smaller than 0.25 mm (WT < 0.25 mm) increased significantly in aeolian sandy soil and chernozem. C and N content declined with increasing rainfall intensity across all soil types, with the most pronounced losses in aeolian sandy soil. Structural equation modelling further demonstrated that rainfall intensity regulated erosion through soil‐specific pathways: nutrient and compaction effects dominated sediment responses in aeolian sandy soil, WT < 0.25mm controlled erosion in chernozem, and shear strength primarily regulated runoff in mollisol. These findings enhance understanding of rainfall‐induced erosion processes in Northeast China and inform region‐specific soil conservation strategies.