How do the properties and characteristics of soil change when it gets wet?

1 Answer
Sep 25, 2017

Taking two primary characteristics - composition and pH - wet soil will usually expand, and it will equilibrate the pH of components to a more uniform level.

Explanation:

Dry soil does not really have a "pH" because that is a measure of hydrogen ions in solution. But, it does have the compounds in it that will make the soil more alkaline or acidic when it gets wet.

Beside simply "adsorbing" moisture, soil will usually expand as it fills with water. That is why dry fields and roads can turn into sticky mud pits when wet.

A cycle of wetting and drying soil will affect its weathering by the chemical interaction of components (e.g. pH) and the further breakdown of larger particles, and mixing of the soil materials.

Excessive wetting may lead to soil erosion through runoff in the water.