Soil compaction is a decrease in pore space driven by mechanical stresses. It is prevalent in agriculture, forestry and construction due to too high wheel loads by machinery, leading to adverse impacts to drainage, aeration and soil strength that affects plants and exchanges between soils and the wider environment. Compaction arises when a mechanical stress exerted on the soil exceeds its internal strength. The applied stress attenuates with depth, but mitigating subsoil compaction is more difficult than compaction of the upper soil layers.