Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: The extent of sodium hazard is increased in irrigated agricultural area.
Reason R: Carbonate and bicarbonate are present in irrigation water.
In light of the above statements, choose the correct answer from the options given below:

• 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:

Sodium hazard is measured by SAR (Sodium Adsorption Ratio).
Carbonates and bicarbonates increase sodium hazard.
Gypsum is used to reclaim sodic soils.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This question tests knowledge of irrigation water quality and sodium hazard.

Step 2: Detailed Explanation:
Assertion A:
Sodium hazard in irrigated areas is indeed increased due to the use of irrigation water containing salts.
This is a known issue in arid and semi-arid regions.
This statement is true.
Reason R:
Carbonate and bicarbonate ions present in irrigation water react with calcium and magnesium.
This leads to the precipitation of Ca and Mg as carbonates.
Sodium concentration increases relative to Ca and Mg, causing sodium hazard.
This statement is true and explains A.

Step 3: Final Answer:
Thus, both A and R are true and R is the correct explanation of A, which corresponds to option (A).
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