-Formed by weathering of pre-existing rocks, minerals, & organic matter by exposure of surface. -Consist of minerals, air, water, and organic matter. -Needed to support primary producers (plants) --> vital natural resource. No producers = no consumers. -Over 17,000 types; 5 major types; 12 soil orders.
-Holds nutrients and water, waste decomposer, produces and absorbs gases, habitat for organisms.
Soil as a system
-Dead and living microorganisms. -Decaying material. -Bacteria. -Habitat for earthworms, insects, mammals, reptiles, and amphibians.
5 factors that determine soil formation and characteristics
-Parent material -Climate -Organisms -Topography -Time
How long does soil formation take?
-Very slow process --> hundreds to thousands of years for an inch to form. -Soil is a marginally renewable resource.
Must be: -Naturally occurring. -Inorganic. -Solid. -Have definite chemical composition. -Have an internal crystal structure.
-Over 2,500 known. Limited by abundance of elements. -92% are silicates. -8% are oxides, sulfides, and carbonates.