Which of the following is not a characteristic feature of the humus?

Options

A. It is a dark coloured, amorphous substance
B. Highly resistant to microbial action
C. It is reservoir of nutrients
D. Cannot be degraded further

Answer

To solve the question of which option is not a characteristic feature of humus, we can analyze each option provided:

1. **Option A: It is a dark colored amorphous substance.**
- Humus is indeed known for its dark brown color and amorphous (non-crystalline) structure. This is a characteristic feature of humus.

2. **Option B: Highly resistant to microbial actions.**
- Humus is resistant to decomposition by microbes, making it a stable component of soil. This is also a characteristic feature of humus.

3. **Option C: It is the reservoir of nutrients.**
- Humus serves as a reservoir of essential nutrients for plants, which is a well-known characteristic of humus.

4. **Option D: It cannot be degraded further.**
- This statement is incorrect. While humus is resistant to microbial action, it can still be degraded by certain microbes over time, which leads to the release of inorganic nutrients through a process called mineralization. Therefore, this option does not accurately describe humus.

Based on the analysis, the answer to the question is **Option D: It cannot be degraded further.**