Which element is required in comparatively least quantity for the growth of plant?

Options

A. Zn
B. N
C. P
D. Ca

Answer

To determine which element is required in comparatively least quantity for the growth of plants, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Essential Elements for Plant Growth**:
- Plants require around 17 essential mineral elements for their growth. These elements are categorized into two groups based on the quantity needed: macronutrients and micronutrients.

2. **Understand Macronutrients vs. Micronutrients**:
- **Macronutrients**: These are elements required in larger quantities (e.g., Nitrogen, Phosphorus, Calcium).
- **Micronutrients**: These are elements required in smaller quantities, often in milligram amounts (e.g., Zinc).

3. **Analyze the Given Options**:
- The options provided are: Zinc, Nitrogen, Phosphorus, and Calcium.
- Among these, Nitrogen, Phosphorus, and Calcium are macronutrients, which means they are needed in larger quantities.

4. **Identify the Element Required in Least Quantity**:
- Zinc is the only element listed that is classified as a micronutrient. It is required in comparatively smaller amounts than the macronutrients.

5. **Conclusion**:
- Therefore, the element required in comparatively least quantity for the growth of plants from the given options is **Zinc**.

### Final Answer:
**Zinc**

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