Water Requirement of Crops MCQ with answer and solution

Concept

Permanent wilting point and available soil moisture limits

Formula

Available Water = Field Capacity - Permanent Wilting Point

Step-by-step solution

1. Statement (i) is correct: Permanent Wilting Point (PWP) is the soil moisture limit below which plants permanently wilt and cannot recover. 2. Statement (ii) is incorrect: Field Capacity (FC) marks the upper limit of available water; PWP marks the lower limit of available water. 3. Available water for plants is the difference between Field Capacity and Permanent Wilting Point. 4. Therefore, only statement (i) is true. Answer: A

Explanation

Permanent Wilting Point (PWP) is a critical soil moisture threshold below which plant roots can no longer extract capillary water from the soil pores, causing permanent wilting. The upper limit of available moisture is Field Capacity (FC), while PWP represents the lower limit of available moisture. Hence, statement (i) is true and (ii) is false.

Why the other options are wrong

B) Incorrect because statement (ii) is false. C) Incorrect because statement (ii) incorrectly claims PWP is an upper limit. D) Incorrect because statement (i) is a scientifically correct definition.

Shortcut

Upper limit = Field Capacity; Lower limit = Permanent Wilting Point.

Common mistake

Thinking PWP is the upper limit of available water rather than the lower limit.