What are biofertilisers? Give two examples.

Explanation

### Step-by-Step Solution:

1. **Definition of Biofertilizers**:
- Biofertilizers are substances that contain living microorganisms, which when applied to soil or plants, promote growth by increasing the supply or availability of primary nutrients to the host plant.

2. **Role of Biofertilizers**:
- These microorganisms enhance the nutrient content in the soil, which is essential for plant growth. They help in the fixation of atmospheric nitrogen, solubilization of phosphorus, and decomposition of organic matter, thereby improving soil fertility.

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