Effect of Straw Content on Soil Compaction Under Agricultural Traffic Conditions

Soil compaction caused by agricultural machinery operations is becoming increasingly serious, damaging soil structure and affecting sustainable agricultural production. However, there has been a lack of systematic research on the quantitative effects of straw on soil compaction. Therefore, this study used the discrete element method to investigate the effects of different straw contents (0–50%) on soil compaction characteristics. The results showed that: (1) When the loading plate sinks at a constant speed of 0.01 m/s, the compressive force on the soil mixture at depths of 50 mm, 100 mm, and 150 mm with 50% straw content is reduced by 669.03 N, 639.79 N, and 382.04 N, respectively, compared to pure soil; (2) When the loading plate was applied with a constant load of 100 N, the compressive forces at the same depths were reduced by 1,289.36 N, 862.9 N, and 607.49 N, respectively. Furthermore, both simulation results and indoor compaction experiments indicate that settlement decreases with increasing straw content. Pore ratio analysis confirms that the “micro-spring” effect of straw can improve soil compressive strength. This study provides guidance for enhancing agricultural machinery mobility and mitigating soil compaction hazards.