Soil
Soil is material capable of supporting plant life. Soil forms through a variety of soil formation processes, and includes weathered rock "parent material" combined with dead and living organic matter and air.Soils can be divided into two general layers: topsoil, the topmost layer, where most plant roots, microorganisms, and other animal life are located, and subsoil, which is deeper and often more dense and contains less organic matter.. For more information about the topic Soil, read the full article at Wikipedia.org. Related articles: Humus — Humus is a complex organic substance resulting from the breakdown of plant material in a process called humification. This process can occur ... > read more Infiltration (hydrology) — Infiltration is the process by which water on the ground surface enters the soil. Infiltration is governed by two forces, gravity, and capillary ... > read more Soil pH — Soil pH is an indication of the alkalinity or acidity of soil. It is based...