What type of soil condition can lead to very hard soil in turfgrass?

Heavy soils can lead to very hard soil conditions in turfgrass due to their composition, which typically includes a higher percentage of clay particles. Clay soils have small, densely packed particles that retain water and can become compacted easily under pressure, especially when they dry out. The compaction caused by foot traffic or other activities can create a hard, impenetrable surface that hinders root growth and reduces overall turf health.

In contrast, excess drainage generally promotes aeration and prevents soil from becoming hard because it allows for more air and moisture circulation within the soil structure. High moisture content may lead to waterlogged conditions, but it does not inherently cause soil hardness; instead, it can create a soft, wet environment that may eventually dry out and harden if fluctuations in moisture occur. Extensive aeration, when done properly, is intended to alleviate compaction rather than contribute to it. Therefore, among the choices, heavy soils are most directly linked to creating hard soil conditions in turfgrass.