How is Soil Formed?
There are thousands of different soils throughout the world. Soils are formed through a combination of five important factors.
Parent Material - Earthy materials, both mineral and organic. Parent material can be a volcanic deposit such as ash; it can be a sediment that has been transported and deposited by wind or water; or it can be a deposit left by glaciers.
Climate - Parent material is broken down into finer particles by a process called weathering, which is controlled by the climate of a given location. Temperature and water are major climatic forces that influence weathering.
Living Organisms - Both plants and animals help to create soils. As they die, plants and animals add organic matter to weathered parent material to help form subsoil and topsoil. As animals dig through the soil, they break it up, permitting more are and water to enter.
Topography - Topography is the hilliness, flatness, or amount of slope of the land.
Time - The age of a soil must be considered in thousands and even millions of years since it may take hundreds of years for these factors to form one inch of soil from parent material.