The process of increasing fertility of soil by the earthworm is called -

Options

A. Vermicomposting
B. Chemicomposting
C. Chemimanuring
D. Percolation

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Earthworms**: Earthworms play a crucial role in soil fertility. They consume organic matter and excrete it in a form that is rich in nutrients, which enhances soil quality.

2. **Identifying the Process**: The specific process by which earthworms contribute to soil fertility is known as vermicomposting. This involves the breakdown of organic waste by earthworms, leading to the production of nutrient-rich compost.

3. **Evaluating the Options**:
- Option 1: Vermicomposting - This is the correct process involving earthworms.
- Option 2: Camey composting - This is not a recognized term related to earthworms.
- Option 3: Camey manuring - This also does not relate to the process of earthworms enhancing soil fertility.
- Option 4: Percolation - This refers to the movement of water through soil and is unrelated to earthworm activity.

4. **Conclusion**: Based on the definitions and roles of the processes listed, the correct answer is that the process of increasing the fertility of soil by earthworms is called **vermicomposting**.

**Final Answer**: Vermicomposting

---