Estimating sediment transport capacity on sloping farmland on the Loess Plateau considering soil particle size characteristics

•Tc of soils with varied particle size characteristics was contrasted.•Stream power were preferably recommended to predict Tc for four soils.•Median particle size (D50) and kurtosis (Kg) were significantly correlated to Tc.•The inclusion of D50 and Kg greatly improved the predictive accuracy of Tc equations. The sediment transport capacity (Tc) is essential for understanding soil erosion and creating soil erosion prediction models. Although many Tc equations exist, they are not universally applicable to sloping farmland on the Loess Plateau. To tailor Tc equations for this region, Tc for four soils (Shenmu Inceptisol (SMI), Shenmu Entisol (SME), Ansai Inceptisol (AS), and Yongshou Alfisol (YS)) from sloping farmland on the Loess Plateau was determined through flume tests with slopes ranging from 15.84 % to 38.39 % and flow discharges of 0.05 to 0.11 m2 min−1. Additionally, appropriate particle size characteristics were selected to distinguish the soil types. The results revealed that the Tc of SME exceeded that of YS, followed by SMI and AS in descending order. The Tc of the four individual soils increased exponentially with flow discharge (Q) and slope (S). Tc for individual soils could be satisfactorily predicted using power functions of mean velocity, shear stress (τ), stream power (ω), or effective stream power (R2: 0.661–0.950, MAE: 0.020–0.110, RMSE: 0.023–0.151), with ω being identified as an optimal hydraulic parameter for simulating Tc. In contrast, the unit stream power was a poor predictor of Tc for individual soils (R2: 0.403–0.700, MAE: 0.035–0.123, RMSE: 0.040–0.161). The median particle size (D50), sorting coefficient, and kurtosis (Kg) exhibited highly significant positive correlations with Tc (P