What happens during soil compaction?

During soil compaction, the primary action that occurs is the pressing together of soil particles. Compaction reduces the space between the particles, leading to decreased pore space in the soil. This process can make the soil denser, affecting its physical properties significantly.

As a result of compaction, the movement of air and water through the soil can be restricted. This decreased porosity can create challenges for root growth and can hinder the soil's ability to hold water effectively, contrary to options that suggest water retention is increased or microbial diversity is enhanced. In fact, compacted soils often exhibit reduced organic matter and microbial activity due to less aeration and harder conditions for organisms to thrive. Therefore, the relinquishing of space between particles and the resultant density is what makes the process of soil compaction crucial to understand in soil management practices.