Arrange the following soil horizons from top to bottom:
A. Oₐ Horizon B. E-Horizon C. A-Horizon D. B Horizon E. Oᵢ Horizon
Choose the correct answer

Correct option is B

The correct sequence for the soil horizons from top to bottom is:
1. E. Oᵢ Horizon – The uppermost layer of fresh organic material.
2. A. Oₐ Horizon – The decomposed organic material layer below the Oᵢ Horizon.
3. C. A-Horizon – Known as the topsoil, where mineral matter mixes with organic material.
4. B. E-Horizon – A zone of leaching or eluviation, where minerals are washed out.
5. D. B Horizon – The subsoil, where minerals and nutrients accumulate.
Explanation:
· Oᵢ Horizon (E): Contains fresh, undecomposed organic material like leaves and twigs.
· Oₐ Horizon (A): Composed of decomposed organic matter, rich in humus.
· A-Horizon (C): The topsoil layer rich in minerals and organic matter; critical for plant growth.
· E-Horizon (B): Known as the eluviation layer, where materials are leached out.
· B Horizon (D): The subsoil, where minerals leached from the E-Horizon accumulate.
Information Booster:
1. O-Horizon refers to organic layers at the soil surface.
2. A-Horizon is critical for plant growth due to its nutrient content.
3. E-Horizon is a zone of leaching, typically found in acidic soils.
4. B-Horizon accumulates clay, iron, and other leached materials.
5. Soil horizons vary in depth and composition depending on environmental factors.
6. Understanding soil horizons helps in agriculture, forestry, and environmental science.
Additional Knowledge:
· (A) Oₐ Horizon:
· Contains highly decomposed organic matter.
· Dark and rich in nutrients.
· Important for soil fertility.
· (B) E-Horizon:
· Found below the A-Horizon.
· Eluviation process washes out silicate clay, iron, or aluminum oxides.
· Appears lighter in color due to leaching.
· (C) A-Horizon:
· Also called topsoil.
· Contains a mix of organic material and minerals.
· Crucial for supporting plant life.
· (D) B Horizon:
· Also known as the subsoil.
· Accumulates leached minerals from the E-Horizon.
· Rich in clay and iron oxides.
· (E) Oᵢ Horizon:
· The uppermost organic layer.
· Contains fresh, undecomposed organic matter.
· Found in forests and areas with significant organic deposition.
Key Points:
1. Soil profiles consist of multiple horizons.
2. Top layers (O and A Horizons) are rich in organic matter.
3. E-Horizon is characterized by leaching (eluviation).
4. B-Horizon accumulates leached materials (illuviation).
5. Soil layers are essential for understanding agricultural practices and ecosystem health.