With everything else being equal, which soil conditions cause the deepest soil compaction?

The correct choice regarding the conditions that cause the deepest soil compaction is wet soil. When soil is saturated with water, the soil particles lose contact with each other, and the water fills the void spaces that would typically allow for air. This includes heavier, dense soil, where the weight of machinery or human activity exacerbates the compaction process.

In wet conditions, as machinery travels over the surface, it exerts pressure that forces the particles closer together, leading to a denser soil structure and deeper compaction. The water lubricates the particles, allowing them to be pushed together more easily under pressure, which results in a more compacted layer beneath the surface.

In contrast, dry soil tends to be less prone to compaction because the soil particles are more rigid and can resist the compressive forces better. Moist soil exists in a transitional state where some compaction can occur, but not to the extent of saturated soil. Therefore, while moisture plays an essential role in compaction, the presence of excess water leads to the most significant compaction effects due to the dynamics of soil particle movement and the nature of moisture’s influence on soil structure. Soil moisture definitely impacts compaction but remains less influential than saturated conditions.