Question

Which are the fundamental soil-forming process ?
(A) Eluviation
(B) Illuviation
(C) Laterization
(D) Humification
Choose the correct answer from the options given below :

• A. (A), (B) and (C) only.
• B. (B), (C) and (D) only.
• C. (A), (C) and (D) only.
• D. (A), (B) and (D) only.

Hint:

All pedogenic processes can be grouped under four broad fundamental pathways: Additions (e.g., humification), Losses (e.g., leaching), Translocations (e.g., eluviation/illuviation), and Transformations (e.g., weathering).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Soil-forming (pedogenic) processes are categorized into fundamental processes and specific processes.
Fundamental processes occur universally in all soils across the globe, whereas specific processes are restricted to specific climatic zones, parent materials, or vegetation types.

Step 3: Detailed Explanation:
Let us classify the soil-forming processes listed:
1. Fundamental Soil-Forming Processes: These processes occur in every soil profile to some degree. They include:
- Humification (D): The transformation of raw organic matter into stable humus by soil microbes.
- Eluviation (A): The downward translocation of soil constituents (clay, oxides, organic matter) out of an upper horizon (exit).
- Illuviation (B): The deposition and accumulation of these eluviated materials into a lower horizon (into).
Because these processes occur universally in all soils, they are fundamental soil-forming processes.
2. Specific Soil-Forming Processes: These processes require specific environmental conditions to occur.
- Laterization (C): This is the intensive leaching of silica and accumulation of iron and aluminum oxides, which occurs exclusively in hot, humid tropical climates.
Other specific processes include podzolization, calcification, salinization, and solonization.
Therefore, (A), (B), and (D) are fundamental processes, while (C) is a specific process.

Step 4: Final Answer:
The fundamental soil-forming processes are (A), (B), and (D) only, corresponding to option (D).