Discrete element method (DEM) and soil bin evaluation of farmyard manure and tire traffic on the soil compaction

The research investigates the impact of farmyard manure application and tire traffic on soil compaction using a combination of soil bin tests and Discrete Element Method (DEM) simulation. Tests were conducted in the controlled condition of soil bin facility utilizing a well-equipped single-wheel tester. An agricultural tractor tire of 220/65R21 manufactured by Goodyear was used. Then DEM was employed to model soil-tire interactions, considering factors such as soil properties, tire design, and tire traffic. The DEM model was calibrated using laboratory experiments, including uniaxial compression test and repose angle measurement. The results revealed a significant and good correlation between laboratory method and the DEM through the examination of soil density variations at different depths and organic matter ratios. A comparison between the DEM and experiments revealed a strong correlation, with an R² value of 0 9924, a correlation coefficient of 0.996, and P-value less than 0.05. It was found that increasing soil depth leads to decrease in bulk density and the application of manure resulted in loosening of the soil and subsequently significantly reducing its bulk density. DEM method showed a significant increase in density from 1 to 3 passes at the shallow depth of 10 cm, followed by a continuous increase in density from 3 to 16 passes. The DEM simulations provided valuable insights into the mechanisms of soil compaction and the effects of different management practices. This research highlights the potential of DEM as a powerful tool for studying soil-tire interactions and optimizing agricultural practices to minimize soil compaction.