Soil is an underated and forgotten commodity, but as Doran and Parkin say, “the thin layer of soil on the surface of the earth represents the difference between survial and extinction for most terrestrial life”. The quality of the soil dictates the plant growth in virtually all environments. Soil is the habitat for millions of organisms, nature’s recycler, the medium for plant and therefore animal, growth, an agent of landscape change and a store of history. It’s a big deal.
Pedology (the study of soils) links the lithosphere (earth’s core/crust) biosphere, atmosphere and hydrosphere. Only 5% of soil is organic matter. Of the rest, 25% is air, 45% is minerals and 25% is water. The parent material is usually the rock which makes up most of the unconstitued material just above the bed rock and under the top soil. In between the top soil and the bedrock you can sometimes get many layers (horizons) of different soil.
Doran and Parkin, In Holden, J. Ed. (2005) An introduction to Physical Geography and the Environment. First edition. Harlow.
Fitzpatrick, E.A. (1983) Soils: Their Formation, Classification and Distribution. First Ed. Harlow.
Avery, B.W. (1990) Soils of the British Isles. CAB International. Wallingford.
