How does soil compaction affect plant growth?

Soil compaction significantly impacts plant growth primarily by reducing pore space and impeding root growth. When soil particles are compressed, the spaces between them—where air and water are typically held—become diminished. This reduction in pore space constrains roots from expanding and accessing vital resources such as water, nutrients, and oxygen.

The impediment to root growth is critical because healthy roots are essential for a plant's stability, nutrient uptake, and overall health. Compacted soil creates a dense layer that roots struggle to penetrate, often leading to stunted plant growth or, in severe cases, plant death. Additionally, limited pore space reduces the soil's ability to retain moisture and exchange gases, which are both critical for root function and plant health.

In contrast, the other options suggest outcomes that are simply not conducive to healthy plant development in compacted soils. For instance, increased nutrient availability and enhanced water infiltration do not occur under compacted conditions, as both processes rely on adequate pore space to function effectively. Encouraging deeper root growth also contradicts the reality of compaction since it physically limits root extension. Thus, understanding the mechanisms of soil compaction highlights its detrimental effects on plant growth.