Fertilisers are the chemicals rich in

Options

A. N
B. P
C. K
D. all of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Fertilizers**: Fertilizers are chemical substances that are added to soil or plants to provide essential nutrients that promote growth.

2. **Types of Chemicals in Fertilizers**: The primary chemicals found in fertilizers are inorganic substances. These substances are specifically formulated to supply essential nutrients to crops.

3. **Key Nutrients**: The most common nutrients provided by fertilizers are nitrogen (N), phosphorus (P), and potassium (K). These nutrients are crucial for plant growth and development.

4. **Function of Nutrients**:
- **Nitrogen**: Essential for leaf growth and overall plant vigor.
- **Phosphorus**: Important for root development and flowering.
- **Potassium**: Helps in overall plant health and disease resistance.

5. **Impact of Fertilizers**: While fertilizers can significantly enhance crop production and lead to healthier plants, excessive use can negatively affect soil health and fertility over time.

6. **Conclusion**: Therefore, fertilizers are rich in essential chemicals such as nitrogen, phosphorus, and potassium, which are vital for improving crop yield and ensuring disease-free plants.

**Final Answer**: Fertilizers are chemicals rich in nitrogen, phosphorus, and potassium.

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