How do you damage soil?

Answer 1

That depends on what you mean by "damage"!

High temperatures can effect the structure and mineralogy of a soil which can effect it's physical characteristics such as density and shear strength.

Deformation of the soil can cause the alignment of clay minerals creating preferential planes of weakness which will reduce the soils shear strength to the residual value making failure of a soil slope or punching failure of a foundation built on a soil more likely to occur.

Seasonal fluctuations in weather can have a strong impact on clay soils, for example in the summer months with higher temperatures (and in turn higher net radiation and evapo-transpiration) can remove moisture from the soil. This causes soil suctions (more correctly termed negative pore water pressure) and a consequent decrease in soil volume. This can in turn induce the formation of dessication cracks.

These act as high permeability pathways deeper into the soil making the vertical permeability higher than it otherwise would be. As such during periods of high rainfall the pore water pressure increases much more rapidly at depth than would otherwise be expected, which can act to create instability in embankments and other soil slopes and also leads to "wetting up" of the soil at a greater depth than would otherwise occur. This in turn causes clay minerals to swell and the volume of the soil mass over a greater depth than normal to increase.

These seasonal volume fluctuations are a form of deformation and act to reduce the stiffness and strength of the soil over time. This is known as strain softening behaviour.

Mechanical acts can damage soil. For example weathering and erosion processes, be they natural or caused by man act to break down and or move soil from one place to another. The most obvious example of this is on footpaths in national parks where the "trampling" of thousands of human feet have caused significant erosion.

This is a very brief overview of a very large topic but hopefully should give you some ideas about the subject.

Answer 2

Soil can be damaged by activities such as overgrazing, deforestation, excessive tilling, and pollution from chemicals or heavy metals. These activities can lead to erosion, loss of soil fertility, compaction, and contamination, which can negatively impact plant growth and soil health.