Illuvial accumulation or 'wash-in' processes transpire within which specific soil horizon?
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Answer: C. B
Explanation
The B horizon is the subsoil layer characterized by illuvial accumulation of various minerals. Clay, iron oxides, aluminum, and humus wash down from upper horizons and accumulate here. This illuvial wash-in process creates a denser, often distinctively colored subsoil layer. Soil profiles develop distinct master horizons designated by letters like O, A, E, B, and C. Illuviation involves the deposition of materials leached from overlying eluvial E horizons. Subsoil B horizons play a crucial role in water retention and nutrient storage capacity.
Pedologists identify B horizons in the field by their strong structure and illuvial clay coatings. Foundation engineers evaluate B horizon stability when assessing subgrade soil load capacities. Agricultural roots penetrate into the B horizon to access stored moisture during dry periods. Option A is the E horizon, which is an eluvial layer depleted of clay, iron, and aluminum. Option B is the O horizon, consisting primarily of organic litter and decomposing plant debris. Option D is the A horizon, representing the topsoil layer rich in dark organic matter.
- Subject
- Agriculture
- Category
- Agriculture
- Topic
- —
- Difficulty
- medium
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