Explain how does Nitrobacter increase the soil fertility.

Explanation

### Step-by-Step Solution:

1. **Introduction to Nitrobacter**:
- Nitrobacter is a type of bacteria known as nitrifying bacteria. It plays a crucial role in the nitrogen cycle, which is essential for soil fertility.

2. **Role in the Nitrogen Cycle**:
- Nitrobacter specifically helps in the conversion of nitrites (NO2-) into nitrates (NO3-). This process is vital because nitrates are a more stable and usable form of nitrogen for plants.

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