Surface Runoff and Sediment Yield Modelling Under No‐Till: Chiselling and Crop Management Effects

ABSTRACT No‐till conserves the soil by minimizing disturbance and maintaining crop residue on the surface; however, runoff generation and propagation on no‐till hillslopes are not well understood due to the high cost and labor requirements of field monitoring. Hydrological models can help advance this understanding by simulating runoff, sediment yield, and infiltration under different management conditions. This study evaluated the performance of the LISEM model in simulating runoff and sediment yield on hillslopes under no‐till agriculture with different soil management practices (with and without chiseling) and cover crop levels, and compared model‐simulated infiltration (Green‐Ampt method) with apparent infiltration derived from field observations. Rainfall events were monitored from 2014 to 2018 in experimental units of 0.6 ha and 2.5 ha. Nineteen events covering a range of rainfall intensities and seasons were recorded using manual and automatic measurements (2–5 min intervals). LISEM was calibrated and validated for runoff and sediment yield at both spatial scales. For calibration events, Green‐Ampt infiltration was directly compared with apparent infiltration estimated from rainfall‐runoff data. Model performance was assessed using NSE and PBIAS. Runoff simulations showed good calibration (NSE = 0.99) and satisfactory validation (NSE > 0.5). Sediment yield was well reproduced during calibration but showed lower accuracy in validation, requiring reduced soil cohesion to match observed values. Infiltration simulated by the Green‐Ampt method correlated strongly with apparent infiltration (NSE > 0.98), especially at the larger scale, where spatial variability is lower. Overall, the results demonstrate that LISEM can adequately represent runoff processes and infiltration in no‐till systems with different management practices and surface cover conditions. The model provides a useful tool for evaluating and designing conservation practices, such as broad‐based terraces and retention or detention structures, aimed at mitigating excess runoff and soil loss in agricultural landscapes.