Irrigation Efficiencies MCQ with answer and solution

Concept

High initial cost is the main drawback of drip irrigation. Clogging of emitters is a separate drawback that needs flushing and supervision.

Step-by-step solution

1. Assertion: Drip irrigation needs pipes, emitters, filters and fertigation units, so its initial cost is high. This is the main disadvantage, so the Assertion is true. 2. Reason: Emitters can clog with silt, salts or algae. So laterals need regular flushing and the system needs supervision. The Reason is true. 3. Check the link: Flushing and supervision are running (maintenance) needs. They do not cause the high initial investment. 4. So both are true, but the Reason is not the correct explanation. Answer A.

Explanation

Drip irrigation is costly to install because of its pipe network, emitters and filters. It also needs regular flushing and supervision because emitters clog easily. These are two different disadvantages, so the Reason does not explain the Assertion.

Why the other options are wrong

B: The Reason is also true, because clogging makes flushing and supervision necessary. C: Both statements are true, not false. D: Maintenance needs do not explain the high initial (capital) cost.

Shortcut

Initial cost is capital cost, while flushing is maintenance. Different causes means option A.

Common mistake

Choosing D just because both statements are drip irrigation disadvantages, without checking the cause-effect link.