Question Bank • QB_IDE_EXP_011 MCQ • 1 Mark

Section 5: Irrigation and Drainage Engineering

Soil-Water-Plant Relationship

Subtopic: Water requirement of crops

Question Statement:

The moisture extraction pattern by plant roots in a uniform soil profile typically follows the 40-30-20-10 rule. The percentage of total water extracted from the top quarter ($25\%$) of the root zone depth is:

Options:

  • (A) $40\%$
  • (B) $30\%$
  • (C) $20\%$
  • (D) $10\%$

Answer Key:

A

Step-by-Step Solution & Explanation

The standard 40-30-20-10 moisture extraction pattern indicates that plant roots extract: • $40\%$ from the 1st quarter depth (top quarter) • $30\%$ from the 2nd quarter depth • $20\%$ from the 3rd quarter depth • $10\%$ from the bottom quarter depth.
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