Investigation on the mechanism for crushing root-stubble and disturbing soil by bionic cutters and multi-curved cutters based on DEM

In this study, to address the challenges of root-stubble crushed insufficiently and excessive disturbance of the soil on ridges, moving and fixed cutters imitating a cat’s claw were designed for crushing stubble efficiently through reverse engineering technology. The multi-curve cutter was designed based on the distribution characteristics of roots in different soil layers, enabling efficient crushing of roots with minimal soil disruption. The EDEM was employed to build a root-stubble-soil discrete element model and simulate the crushing process of root-stubble. The accuracy of the result of the numerical simulation was validated through the field test. The qualified rate of root-stubble length, the rate of soil disturbance, and the power consumption of the device (PCD) would be increased with the increase of the rotational speed of cutter shaft (RSCS). The stubble, driven by the moving cutters, rotated around its root until a cutting support was established between the moving and fixed cutters, enabling efficient fragmentation. At a lower RSCS, the disturbed soil in the surface layer would fall back to the ridge. The soil in the middle and deep layers would also be collided and compressed by the soil in the surface layer, and a low rate of soil disturbance would occur. When the RSCS was 380 r/min, the rate of soil disturbance was the lowest, at 18.57%, and the qualified rate of root-stubble length could reach 91.07%, which could meet the requirements of agricultural technology.