Understanding and experimental analysis of soil disturbance by tillage tools with different outer contours

To investigate the soil dynamics affected by the tillage tools with different lateral outer contours, three distinct contour profiles were designed, and a soil bin experiment was conducted. The contour profiles of the tools included a straight line, a concave brachistochrone, and a convex brachistochrone. The experimental conditions involved two soil types (sandy soil and clay soil) with moisture content ranging from 10 % to 30 %, and tool operating speeds varying from 0.03 to 0.15 m/s in increments of 0.03 m/s. In this study, Digital Particle Image Velocimetry (DPIV) was employed to measure soil disturbance caused by the tools, focusing on the fine movement of soil particles, a phenomenon often overlooked in previous studies. The final state of soil movement was categorized into two distinct areas: a covered area and an uncovered area. The experimental results indicated that the covered area predominantly determined the variation in disturbed soil when changes were made to the soil moisture content and tool velocity. In contrast, the uncovered area was largely unaffected by variations in soil moisture content or tool movement. Additionally, the interaction force between the soil and tool was investigated, revealing that it was more sensitive in clay soil compared to sandy soil. • DPIV technology measured the micrometer level of soil particles movement on surface. • Uncovered area is insensitive to the condition of soil moisture content and tool movement. • Concave contour tools outperforming flat and convex in CA and UCA ranking.