What effect does increasing soil compaction have on moisture retention?

Increasing soil compaction typically increases moisture retention in the soil. When soil particles are compacted, the arrangement of those particles becomes denser, which reduces the size of the pore spaces between them. Initially, this may seem counterintuitive, as you might assume less space would mean less ability to hold water. However, compacted soils can actually retain moisture more effectively due to improved contact between soil particles that enhances capillary action, allowing water to be stored in smaller pore spaces that can be held against gravitational pull.

In addition, well-compacted soil can minimize large voids that allow water to drain quickly, leading to improved moisture retention overall. It's important to note that moisture retention is influenced by the overall structure of the soil, including its texture and the properties of the different soil materials present. While the correct answer indicates that compaction generally leads to increased moisture retention, the effects can vary for specific soil types, meaning there are nuances in practice.