How does soil structure typically form?

Soil structure typically forms through natural processes that influence the arrangement and organization of soil particles into aggregates or peds. Wetting and drying cycles are significant contributors to soil structure formation because they cause fluctuations in moisture content that lead to physical changes in the soil.

When soil becomes wet, it expands due to the water that fills the pore spaces between soil particles. Conversely, as it dries, the soil particles contract. This repeated cycle not only impacts the soil's texture but also promotes the aggregation of particles, ultimately leading to the development of a stable soil structure. The formation of stable aggregates improves aeration, water retention, and root penetration, which are essential for plant health.

In contrast, processes like soil erosion, the addition of chemical fertilizers, and heavy machinery compaction typically do not aid in establishing a stable soil structure. Erosion tends to disrupt the existing structure, chemical fertilizers may alter nutrient availability without significantly affecting physical particle arrangement, and compaction can lead to soil density and rigidity, often resulting in a detrimental effect on soil structure rather than its formation.