Question

The C:N ratio of wheat straw is approximately

• A. 5:1
• B. 10:1
• C. 15:1
• D. 20:1

Hint:

C:N ratios:
- Wheat straw: 20:1.
- Legume straw: < 20:1 (10:1).
- Rice straw: 30-40:1.
- High C:N slows decomposition.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
This question tests knowledge of the carbon to nitrogen (C:N) ratio of crop residues.

Step 2: Detailed Explanation:
The C:N ratio of wheat straw is approximately 20:1 (D).
Wheat straw has a relatively high C:N ratio, which affects its decomposition rate.
Materials with C:N > 20:1 immobilize nitrogen during decomposition.
Other crop residues:
- Legume residues: C:N < 20:1 (e.g., 10:1).
- Rice straw: 30-40:1.
- Maize straw: 40-60:1.
Thus, wheat straw has a C:N ratio of about 20:1.

Step 3: Final Answer:
Thus, the C:N ratio of wheat straw is approximately 20:1, which corresponds to option (D).
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