A driven-elastic straw clearing device for strip tillage based on DEM-MFBD coupling simulation significantly improves maize seedling emergence rate

Abstract

The traditional passive-rigid straw clearing device (PRSCD) is difficult to achieve a balance between high straw clearing rate (SCR) and low soil disturbance rate (SDR), resulting in maize seedling emergence rate (SER) consistently below 90.7 % in strip tillage operation mode. In this study, a new driven-elastic straw clearing device (DESCD) that combined driven rotation with elastic material was innovatively developed, and a DEM-MFBD coupling model was constructed to accurately simulate the straw clearing operation process. The simulation results showed that the deformation under force of the elastic rake tine of DESCD reduced the impact on soil particles, which in turn significantly reduced SDR (P ≤ 0.01). Meanwhile, the driven rotation mode could provide stable rotational momentum for DESCD, and then significantly increase SCR (P ≤ 0.01). The elastic deformation coefficient k and driven rotational speed n of DESCD had a significant effect on SCR and SDR (P ≤ 0.01), and the optimal parameter combination of DESCD was k of 780 N mm (°)⁻¹ and n of 280 rpm. The field verification experiment results showed that compared with PRSCD, DESCD could increase SCR by 13.19 % without significantly increasing SDR, which in turn improved SER by 5.78 %. Meanwhile, there was no significant difference between the SCR and SDR calculated by the DEM-MFBD coupling simulation model and the actual field experimental data (P > 0.05). In summary, a new high-performance straw clearing device and a high-precision parameter simulation and optimisation design method were developed for significantly improving the maize SER in strip tillage in this study.