A soil profile is a sequence of horizons (layers with distinctive properties). Soils are characterized, named and managed based on profile characteristics. A generalized view of a Soil Profile: Please note this is an exaggerated simplistic illustration. |
O Horizon: Organic leaves and debris.
A Horizon: Topsoil; brownish from humus; often sandy.
E Horizon: Light colored, leached; sandy.
B Horizon: Clayey, often red-yellow; blocky structure.
C Horizon: Sandy, various colors, not blocky; weathered rock (saprolite).
R Horizon: Hard rock.
Note that not all horizons are present in any given soil; the presence and properties of the horizons are used to describe and name individual soils.The key to describing soil profiles is first to look for a B horizon; these are usually brightly colored (red/yellow), are clayey (have a clayey textural name), and have a blocky structure. Once you see a B, then below is the C, and above the A (with or without an E- they are commonly not present). Try to name the following horizons:
___ 0-1” leaves and twigs.
___ 1-6” brown sandy loam; granular structure.
___ 6-10” light brown sandy loam; granular structure.
___ 10-36” reddish brown clay; blocky structure.
___ 36-45” reddish and yellowish brown sandy loam; massive.
___ 45”+ hard schist.