Study on Rotary-Cutting Behavior Toward Maize Root–Soil Composite for Reducing Consumption
The high-value utilization market for crop straw renders the development of stubble management technology crucial. This study aims to reduce the energy consumption of L-shaped rotary blades during stubble-breaking. Based on a theory analysis of the rotary-cutting operation process, this study involved the burial of the in situ maize root–soil composite in an indoor soil bin, and investigated the effects of rotary speed (275, 330, 385, 440 rpm) and working depth (50, 85, 120 mm) on torque, power, and energy. Field verification yields an overall average relative error of 2.76% across six replicates, verifying that the indoor test method can reliably reproduce field cutting conditions. As the high-speed video images show, a reduction in rotary speed coupled with an augmentation in working depth has the potential to result in residue entanglement and secondary cutting, thereby leading to an escalation in consumption. As the working depth increased, peak torque appeared at a deeper penetration position. The analysis of the computer-aided geometric model section of the root–soil composite indicated that the diameter of the branching root was the primary factor influencing peak torque. At a working depth of 85 mm, the average power savings ranged from 2.26% to 24.8% compared to 50 mm and 120 mm. Despite the increase in average power, peak power, and specific energy requirements at all operational depths with increasing rotary speed, torque reached its minimum at 385 rpm. At 385 rpm, average torque hits its minimum to mitigate component wear, though power and specific energy rise monotonically with rotational speed. The multi-index evaluation balancing mechanical load, energy loss, and residue delivery identifies 385 rpm paired with 85 mm depth as the optimal parameter set. The optimized parameter combination delivers a quantifiable sustainable residue management scheme that balances ecological residue treatment and economic machinery operation costs, supporting low-carbon, sustainable production.