Definition

Noun 1. A soil layer: The B-horizon is a subsurface layer of soil found immediately below the topsoil (A-horizon). It is characterized by the accumulation of materials such as clay, iron, aluminum oxides, and organic compounds that have been leached (washed down) from the layers above.

Examples

• Noun:
  • The B-horizon in this forest soil has a distinct reddish color due to accumulated iron oxides.
  • Soil scientists took a core sample to examine the composition of the B-horizon.
  • Plant roots often extend into the B-horizon to access water and minerals stored there.

Advanced Usage

• "Argillic horizon": A specific type of B-horizon where clay accumulation is the dominant process.
  • The presence of an argillic horizon indicates significant clay translocation over time.
• "Subsoil": A common, less technical synonym for the B-horizon.
  • The subsoil (or B-horizon) is typically denser and less fertile than the topsoil.

Variants and Related Words

• Soil horizon: The general term for a distinct layer of soil. The B-horizon is one of the master soil horizons (O, A, E, B, C, R).
• A-horizon (n): The topsoil layer, rich in organic matter, located above the B-horizon.
• C-horizon (n): The layer of partially weathered parent material found below the B-horizon.
• Eluviation (n): The process of leaching materials a soil layer.
• Illuviation (n): The process of depositing leached materials a soil layer, which is the defining process for the formation of the B-horizon.

Synonyms

• Subsoil: The layer of soil lying immediately under the surface soil.
• Zone of accumulation: A descriptive term highlighting its key characteristic.

Related Terms (Contextual)

• Leaching: The process by which soluble materials are dissolved and carried downward by water through the soil profile.
• Parent material: The underlying geological material from which soil horizons form.

Noun

1. immediately below the A-horizon; contains deposits of organic matter leached from surface soils