Select the option that is appropriate regarding the following two statements labelled Assertion and Reason. Assertion: Proper deep ploughing, which is done by tractors, requires overall less quantity of water and hence, the duty is high. Reason: Ploughing should be done properly and deeply so that the moisture-retaining capacity of the soil is increased.
- AAssertion is true, but Reason is false.
- BBoth Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- CBoth Assertion and Reason are false.
- DBoth Assertion and Reason are true and Reason is the correct explanation of Assertion.Correct
Solution
Concept
Deep and proper ploughing increases the moisture-holding capacity of soil, so less water is needed and duty increases.
Step-by-step solution
1. Duty = area irrigated per unit discharge (ha/cumec). Less water needed for the same area means higher duty. 2. Check the Assertion: deep ploughing by tractors needs less water overall, so duty is high. This is true. It is a standard factor affecting duty. 3. Check the Reason: deep and proper ploughing increases the moisture-retaining capacity of soil. This is true. 4. Link: soil holds more moisture, so fewer waterings are needed, less water is used, and duty is high. The Reason explains the Assertion. 5. So both are true and the Reason is the correct explanation. Answer (D).
Explanation
Deep ploughing loosens the soil, so it can store more water in the root zone. The crop then needs less frequent irrigation, total water use falls, and duty goes up. So the Reason directly explains the Assertion.
Why the other options are wrong
A: The Reason is not false. Deep ploughing does increase moisture retention. B: The Reason is the actual cause of the high duty, so it is the correct explanation. C: Both statements are true, as given in standard irrigation textbooks.
Shortcut
Better ploughing means more moisture stored, less water needed, and higher duty.
Common mistake
Thinking that deep ploughing uses more water and lowers duty, or choosing B without checking the cause-effect link.
Correct answer: D) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.