Question

In general, the depth of irrigation water needed per irrigation to irrigate 1 meter depth of clay loam soil profile at 50% soil-moisture availability is

• A. 20-30 mm
• B. 45-80 mm
• C. 80-120 mm
• D. 120-140 mm

Hint:

Irrigation depth:
- Clay loam: 45-80 mm per irrigation.
- Sandy soil: 20-30 mm per irrigation.
- Heavy clay: 80-120 mm per irrigation.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
This question tests knowledge of irrigation water requirements for different soil types.

Step 2: Detailed Explanation:
For a clay loam soil, the available water capacity is about 15-20% by volume.
For 1 meter depth (100 cm), the available water is about 15-20 cm (150-200 mm).
At 50% soil-moisture availability, the irrigation water needed is about 75-100 mm.
However, in practice, the recommended depth for clay loam soil is 45-80 mm per irrigation.
This accounts for field conditions and irrigation efficiency.
20-30 mm (A): Too low for clay loam.
80-120 mm (C): Too high for clay loam.
120-140 mm (D): Too high.
Thus, the correct answer is 45-80 mm.

Step 3: Final Answer:
Thus, the irrigation water depth needed is 45-80 mm, which corresponds to option (B).
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