April 24, 2017
Soil: A natural body of mineral and organic matter formed at Earth’s surface and capable of
• Formed at Earth’s surface in a fixed spot (Soils don’t move)
o Archives of environmental history. Integral of history of one spot.
o Not as precise as tree rings
o Mineral and organic matter Rocks that have been broken down and
decomposed into organic matter
• A soil=vertical slice
Boundaries between horizons may not always be clear (can be gradual)
o Just organic matter
o Fresh leaf or completely broken down matter
o Dark in color
o High in organic matter
o Where most of biological activity takes place
▪ Roots, critters, etc.