Question

The term 'regur' refers to :

• A. Black cotton soils
• B. Red and yellow soils
• C. Laterite soils
• D. Deltaic alluvial soils

Hint:

Black cotton (regur) soils are classified under the order Vertisols in the USDA soil taxonomy due to their high content of swelling-expanding clays.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
India possesses diverse soil groups classified based on origin, chemical composition, color, and geographic distribution.
Regur is a regional term derived from the Telugu word Reguda, meaning black soil.

Step 2: Detailed Explanation:
Regur soils are commonly referred to as Black Cotton Soils because they have a dark color and are highly suited for cotton cultivation.
These soils are formed in situ by the weathering of Deccan basaltic lava sheets under semi-arid conditions.
Key characteristics of Regur soils include:
- High clay content (typically montmorillonite clay mineral, which has high swelling and shrinking properties).
- High water-retaining capacity.
- Self-ploughing nature: during dry seasons, they develop deep, wide cracks, which facilitates aeration and soil mixing.
- High chemical fertility, rich in calcium, carbonate, magnesium, and potash, but deficient in nitrogen, phosphorus, and organic matter.

Step 3: Final Answer:
The term 'regur' refers to Black cotton soils.