In paddy fields, _____ serves as an important biofertiliser.

Options

A. Rhizobium
B. BGA
C. Glomus
D. Frankia

Answer

**Step-by-Step Solution:**

1. **Understanding the Context**: The question is about identifying an important biofertilizer used in paddy fields. Paddy fields are primarily used for rice cultivation.

2. **Identifying the Biofertilizer**: In paddy fields, the organism that serves as an important biofertilizer is cyanobacteria, commonly known as blue-green algae (BGA).

3. **Role of Cyanobacteria**: Cyanobacteria are significant because they are photosynthetic organisms that can fix atmospheric nitrogen. This means they convert nitrogen gas from the atmosphere into a form that plants can use, which is crucial for soil fertility.

4. **Impact on Soil Fertility**: By fixing nitrogen, cyanobacteria help improve soil fertility, which in turn enhances the growth and yield of rice crops in paddy fields.

5. **Conclusion**: Therefore, the correct answer to the question is that in paddy fields, cyanobacteria (blue-green algae) serves as an important biofertilizer.

**Final Answer**: In paddy fields, **cyanobacteria** serves as an important biofertiliser.

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