Implications of variability in soil structures and physio-mechanical properties of soil after different failure patterns

- Soil physio-mechanical properties significantly decreased after brittle failure.
- The highest Dm and Aspecific values were found after brittle failure.
- The soil structure created after brittle failure was deemed to be the most desirable.
- Brittle failure can be obtained at the sticky limit of a soil.

Soil may fail in a number of ways during tilling, depending on soil conditions and the type of implement. The present paper investigates soil structures and several soil physical and mechanical properties associated with different failure patterns in two agricultural soils (upland and paddy). The dry bulk density, soil cohesion, internal friction angle, and cone index decreased remarkably after brittle failure, while chip-forming and bending failure proved less adequate at modifying these parameters. In addition, the highest soil fractal dimensions and specific surface areas were found after brittle failure in both soils, while the lowest were found after bending failure. However, the Dm and Aspecific of paddy soil were higher than that of upland soil after brittle failure and chip-forming failure patterns, whereas the opposite occurred after bending failure. This study suggests that brittle failure is the most desirable type of soil failure pattern to achieve appropriate tilth, which can be found at the sticky limit of soil.