Question

Assertion (A): Organic mulch conserves soil moisture.
Reason (R): Organic mulches cut off solar radiation falling on the soil surface and reduce evaporation.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Mulches help conserve water by acting as a protective barrier from sun and wind.

Answer 1

The Correct Option is A

Organic mulches reduce soil temperature and minimize evaporation by blocking solar radiation, thus helping retain soil moisture. Hence, both statements are true and R correctly explains A.

Answer 2

Assertion-Reason check method: Test Assertion (A) alone, field studies consistently show mulched soils retain more moisture than bare soils, so (A) is true.
Test Reason (R) alone, a layer of organic mulch (straw, leaves, compost) physically intercepts incoming solar radiation before it reaches the soil surface, keeping the soil cooler and slowing the rate of evaporation, so (R) is also true.
Check the causal link, does blocking radiation and reducing evaporation (R) explain why moisture is conserved (A)? Yes, less evaporative water loss is exactly why moisture is retained.
Both statements hold and the causal chain is direct, so the first option is correct.