What is Subsoil?
Subsoil is the soil layer between topsoil above and the parent material beneath. It has a relatively dense structure with little space for air or water. It is largely uninhabited by soil organisms and contains few roots. It is rich in mineral salts but low in organic content. Subsoil is the soil that’s left after valuable topsoil has been lost to erosion. The thickness of the subsoil layer is seldom more than a few feet.
