Question

Match List-I with List-II 

List-I (Soil Process)		List-II (Description)
A	Eluviation	I	Materials washed down from above are accumulated in the lower part of the profile.
B	Illuviation	II	The separation of material, usually of different grain sizes, by organic activity.
C	Cheluviation	III	Mechanical movement of clay and other fine particles down the profile.
D	Organic sorting	IV	Downward movement of material akin to leaching due to organic chelating agents.

• (A) - (IV), (B) - (III), (C) - (II), (D) - (I)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
• (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
• (A) - (III), (B) - (II), (C) - (I), (D) - (IV)

Hint:

Remember the prefix difference: Eluviation starts with E for Exit (washing out from a horizon), while Illuviation starts with I for Into (accumulation into a lower horizon).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Pedogenesis (soil formation) involves the translocation of organic and inorganic substances across different horizons within a soil profile.
These processes shape the physical and chemical characteristics of distinct soil layers.

Step 2: Detailed Explanation:
Let us analyze each process in the soil column:
1. Eluviation is the physical removal or washing out of chemical substances, dissolved organic matter, and fine mineral particles (like clay) from an upper soil horizon (the E or A horizon) to a lower one. This matches description (III), which details the mechanical downward movement of clay and fine particles. Thus, (A) matches with (III).
2. Illuviation is the deposition and accumulation of the eluviated materials (such as clay, iron, or humus) into a lower horizon (typically the B horizon). This matches description (I). Thus, (B) matches with (I).
3. Cheluviation is a specialized form of eluviation where plant root exudates and decomposing organic matter release soluble organic compounds (chelating agents). These agents bind to iron and aluminum ions, forming soluble metal-organic complexes that are easily leached downward. This matches description (IV). Thus, (C) matches with (IV).
4. Organic sorting describes the biological action of soil fauna (such as earthworms and ants) that selectively transport soil particles, leading to a separation of soil materials of different grain sizes. This matches description (II). Thus, (D) matches with (II).
This yields the combination: (A) - (III), (B) - (I), (C) - (IV), (D) - (II).

Step 3: Final Answer:
The correct matching sequence corresponds to option (C).