Which among the following is not the characteristic of a manure?

Options

A. Manure is not readily soluble in water, thus it is absorbed by plants slowly.
B. Manure is not nutrient specific. It only removes the general deficiency of soil.
C. These are rich in humus but not in inorganic nutrients.
D. These are inorganic salts made by humans.

Explanation

### Step-by-Step Solution:

1. **Understanding Manure**: Manure is a natural substance derived from the decomposition of organic matter, such as animal waste (e.g., cow dung) and plant materials. It is used to enhance soil fertility.

2. **Characteristics of Manure**:
- **Organic Nature**: Manure is 100% organic and does not contain any synthetic chemicals.
- **Nutrient Absorption**: Manure is not readily soluble in water, which means it is absorbed by plants slowly. This slow release helps in sustaining plant growth over time.
- **Nutrient Specificity**: Manure is not nutrient-specific; it helps in addressing general deficiencies in the soil rather than providing specific nutrients.
- **Rich in Humus**: Manure is rich in humus, which improves soil structure and fertility but does not contain inorganic nutrients.

3. **Identifying the Incorrect Statement**: Among the options provided, the statement that describes manure as "inorganic salts made by humans" is incorrect. This statement refers to fertilizers, which are different from manure.

4. **Conclusion**: Therefore, the statement that is not a characteristic of manure is that it is "inorganic salts made by humans."

### Final Answer:
The characteristic that is **not** associated with manure is: "These are inorganic salts made by humans."

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