Changes in near soil-surface traits with crop growth can strongly influence erosion processes during rainfall events and provide valuable insights for farmland management. This study explored how crop growth-induced variations in near soil-surface traits affect soil erosion on gently sloping farmlands. A rainfall simulation experiment with a rainfall intensity of 80 mm h-1 was carried out in runoff plots (5 m x 1.4 m) filled with clay loam with slope gradients of 5.24% and 8.75% at five soybean growth stages (G1-seeding, G2-jointing, G3-final flowering, G4-grain forming, and G5-ripening). Near soil-surface traits were measured, and runoff and sediment samples were collected and measured. The results indicated that the variation in near soil-surface traits was time-dependent and showed weak to strong temporal variations. Overall, the measured runoff and sediment rates showed temporal variations, first decreasing and then increasing with crop growth during the growing season. The mean runoff rate, sediment rate, and sediment concentration decreased by 8%-75%, 13%-92%, and 5%-73%, respectively, in comparison with the bare soil. Seasonal variations in the runoff rate, sediment rate, total runoff volume, and total sediment yield were closely related to changes in near soil-surface traits related to crop growth. Linear or exponential functional relationships were found between the runoff volume and near soil-surface traits. This study reflects the positive impact of crop growth on reducing soil erosion and provides theoretical guidance for soil and water conservation in sloping farmlands.