Numerical analyses ridge-forming for whole film-mulching and double ridge-furrow, a discrete element method

[Display omitted] •A comprehensive analysis was conducted on the formation process of ridges from multiple perspectives.•The JKR V2 soil model was calibrated using the drum method.•Data processing was carried out using Python programming methods.•The shape function expression was obtained by fitting the contour data points of the ridge cross-section.•The intensity of soil disturbance was analyzed using regional statistical methods.•Technical support is provided for analysis of ridge forming. The Northwest of China is a typical production mode of rain-fed agriculture, which mostly adopts the whole film-mulching and double ridge–furrow technique to address the difficulty of surface water storage. However, the quality of ridge formation directly affects the water storage on both sides of the ridges, the reliability of plastic film mulching, and the crop growth. This study focused on the process of rotary tillage ridging, took different inclination angles and depths of ridger as variable factors, explored the influence of different operation parameters on the quality of ridge forming. The soil viscoelastic model was established in the study using the discrete element method. The changes in ridger resistance, ridge structure, and soil particle disturbance were analyzed in detailed, respectively. The results indicated that as the inclination angles and depths of ridger increased, the resistance of ridger also increased. The height of the ridges significantly influenced by the inclination angles and depths of ridger, and under the same inclination angles of ridger, the height of the ridges was directly proportional to the depth of ridger. Under different combinations of operational parameters, the height of the small ridges had good agreement with the ridging agronomy. As for the large ridges, when the depth of ridger was 100mm and the inclination angles were 15 °, 30 °, and 45 °, the working parameters met the agronomic requirements for ridge forming. In terms of soil disturbance, the soil located within a range of 30～90mm from the surface was most susceptible to disturbance from the rotary tillage and the ridger, and the soil disturbance was stronger in the small ridges compared to the large ridges. The results of study contributed to a deeper understanding of the rotary tillage ridging process and provided insights into the factors influencing the quality of ridge forming.