Authors

Abstract

To address severe soil compaction, high draft, and low subsoiling efficiency in saline–alkali soils, we designed a soil-breaking subsoiling shovel aimed at reducing draft and improving soil comminution. A discrete element method (DEM) soil model with graded particle sizes was established using the Hertz–Mindlin contact with JKR adhesion, and simulation analyses were combined with an orthogonal experimental design to optimize the shovel’s structural parameters and operating conditions. The optimal combination—blade edge angle 56.97°, blade inclination 44.45°, and forward speed 0.69 m·s⁻¹—yielded a simulated draft of 2731.74N and a maximum particle velocity of 2.75 m·s⁻¹. Field tests at 0.69 m·s⁻¹ measured a draft of 2885.62N, within a 4.49% relative error of the simulation, indicating high predictive reliability. The mean soil comminution rate reached 57.79%, 64.5% above the conservation-tillage threshold (≥35%). These results verify the shovel’s usability and efficiency: the proposed mechanical design reduces draft while substantially enhancing soil fragmentation, and the overall operating performance meets agronomic requirements for saline–alkali land improvement, offering an effective and innovative solution for improving soil structure.

Abstract in Chinese

为解决盐碱土中土壤板结严重、牵引阻力高、深松效率低等问题，本文设计了一种破土型深松铲，旨在降低阻力并提高土壤碎土效果。基于离散元方法（DEM），采用Hertz–Mindlin 接触模型结合 JKR 黏附建立分级粒径的盐碱土模型，并将仿真分析与正交试验设计相结合，优化深松铲的结构参数与作业条件。最优组合为：刃口角 56.97°、破土刀倾角 44.45°、前进速度 0.69 m·s⁻¹；在此条件下，仿真牵引阻力为 2731.74 N，颗粒最大流速 2.75 m·s⁻¹。田间试验在 0.69 m·s⁻¹下测得牵引阻力 2885.62 N，与仿真结果的相对误差为 4.49%，表明模型预测可靠。平均碎土率 57.79%，较保护性耕作阈值（≥35%）提高 64.5%。研究结果验证了所提深松铲的可用性与高效性：该机械设计可在显著降低牵引阻力的同时明显增强碎土效果，其总体作业性能满足盐碱地改良的农艺要求，为改善盐碱土结构提供了有效且具有创新性的技术方案。