What does soil compaction primarily affect in plant health?

Soil compaction primarily affects the air space in the soil. When soil particles are pressed together due to compaction, the voids or spaces between them, which typically allow for air to permeate, are reduced. This decreased air space restricts the amount of oxygen available to the roots, which is vital for plant growth and overall health.

Roots need oxygen for respiration, and a lack of air space can lead to poorly developed root systems, increased susceptibility to disease, and reduced nutrient uptake. While soil compaction does impact factors like water retention and nutrient absorption, the immediate and direct consequence of reduced air space is the most significant concern for maintaining healthy plant life. The other factors play a role, but air space is crucial for root respiration.