Experimental research on straw movement patterns in cross-slope strip tillage based on MBD-DEM coupling

Due to the significant lateral undulation of sloped farmland, existing strip tillage machinery exhibits poor lateral profiling capabilities, severely affecting the effectiveness of cross-slope strip tillage operations. Based on the straw distribution and soil characteristics of sloped farmland in Northeast-China, this study conducted soil angle of repose tests and basic inclined plane experiments using a 2D LiDAR to determine the contact parameters between straw and soil components. A soil-straw composite model is established under different slopes. Using MBD-DEM coupled simulations, the performance of a straw strip clearing device (SSCD) was analysed under varying front tilt angles (FTAs), side tilt angles (STAs), working speeds (WSs), and working depths (WDs). The optimal operating parameters for the SSCD were determined to be 30°, 20°, 3 m s −1 , and 150 mm, respectively. By analysing the trajectories of straw of four different lengths on the sowing strip above and the sowing strip below under different slopes, it was concluded that heavier straw was more affected by slope than lighter straw. Field test results indicated that at a 0° slope, the straw clearing rate (SCR) was 98.1 % for the sowing-strip below and 98.4 % for the sowing-strip above, with a difference of 0.3 %. At a 6° slope, the SCR was 93.3 % for the sowing-strip below and 97.8 % for the sowing-strip above, with a difference of 4.5 %. The discrepancies between simulation and field results were not significant. The designed device meets the agronomic requirements for cross-slope tillage on sloped farmland. • Acquisition of soil repose angle based on LiDAR was developed. • The contact parameters of soil and straw on sloping farmland were determined. • A composite soil-straw model was established for different slopes. • The straw movement patterns were predicted based on MBD-DEM coupling simulation. • Key parameters of the straw strip cleaning device were optimised.