Cyanobacteria help farmers by

Options

A. reducing the alkalinity of soil
B. reducing the acidity of the soil
C. neutralizing the alkalinity of soil
D. water logging

Answer

**Step-by-Step Solution:**

1. **Understanding Cyanobacteria**: Cyanobacteria are photosynthetic prokaryotes that belong to the kingdom Monera. They are also known as blue-green algae and are important in agriculture.

2. **Role in Agriculture**: Cyanobacteria are considered a valuable bio-resource in agriculture due to their ability to fix atmospheric nitrogen. This means they convert nitrogen gas from the atmosphere into forms that plants can use, such as nitrates and nitrites.

3. **Effect on Soil Acidity**: The nitrogen oxides produced by cyanobacteria help in reducing the acidity of the soil. This is crucial because overly acidic soils can hinder plant growth and nutrient availability.

4. **Evaluating the Options**: The question provides four options regarding how cyanobacteria help farmers:
- A) Reducing the alkalinity of the soil
- B) Reducing acidity of soil
- C) Neutralizing the alkalinity of soil
- D) Water logging

5. **Identifying the Correct Answer**:
- Option A (reducing alkalinity) is incorrect because cyanobacteria do not reduce alkalinity; they help reduce acidity.
- Option B (reducing acidity of soil) is correct as cyanobacteria contribute to this process.
- Option C (neutralizing alkalinity) is also incorrect for the same reason as option A.
- Option D (water logging) is unrelated to the role of cyanobacteria.

6. **Conclusion**: Therefore, the correct answer is **B) Reducing acidity of soil**.

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