Question

Most Laterite soils are rich in

• A. Phosphorous and Calcium
• B. Calcium and Magnesium
• C. Molybdenum and Chlorine
• D. Iron and Aluminum

Hint:

Laterite soils: Rich in Iron and Aluminum (Sesquioxides). Highly deficient in Nitrogen, Phosphorus, Potassium, Calcium, and Organic matter.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Laterization (ferrallitization) is a pedogenic process occurring in warm, humid tropical climates characterized by intense chemical weathering and desilication.
Key Formula or Approach:
\[ \text{Laterite Soil} \approx \text{Hydrated Oxides of Iron (}\text{Fe}_2\text{O}_3\text{) and Aluminum (}\text{Al}_2\text{O}_3\text{) [Sesquioxides]} \]

Step 2: Detailed Explanation:
Under alternating wet and dry tropical climates:
Intense leaching washes away soluble basic cations ($Ca, Mg, K, Na$) and silica (desilication).
The residual soil matrix becomes heavily enriched in insoluble, immobile hydrated oxides of Iron (giving laterites their characteristic brick-red color) and Aluminum (sesquioxides, $\text{Fe}_2\text{O}_3$ and $\text{Al}_2\text{O}_3$).

Step 3: Final Answer:
Thus, most Laterite soils are rich in Iron and Aluminum, matching option (D).