RAS question
Black soil (Regur) is most suitable for growing:
Correct answer: (D) Cotton.
Black soil, also called regur or black cotton soil, is most suitable for growing cotton.
Explanation
Black soil is the expected answer because regur is black cotton soil and NCERT connects the black soil of the Deccan Plateau with cotton cultivation. Regur forms from the weathering of Deccan Trap basalt, has high moisture-retention capacity, and shows a wet-swelling, dry-shrinking character often described as self-ploughing. These properties make it especially useful for cotton. NCERT adds the geographical anchor: the black soil of the Deccan Plateau is particularly suitable for cotton cultivation, which explains why textile industries are concentrated in that region. Its mineral profile also fits the standard exam note: rich in lime, iron, magnesia and alumina, but deficient in nitrogen, phosphorus and organic matter.
Why the other options are wrong
- (A) Wheat is not the best match for black regur soil because wheat is primarily associated with alluvial soil.
- (B) Tea is ruled out because it requires acidic soil in hilly areas, not Deccan black cotton soil.
- (C) Rice is not the best answer because it is associated with alluvial or clayey soil and standing water conditions.
Concept
This tests Indian soil types and their crop associations, especially the exam-standard link between regur soil and cotton. It recurs in RAS because soil-crop matching combines physical geography, regional distribution and agriculture in one quick question.