The form of nitrogen from the soil that plant absorbs is

Options

A. `NH_(3)`
B. `N_(2)`
C. Nitrate
D. Nitrite

Answer

**Step-by-Step Solution:**

1. **Understanding Nitrogen in Soil:**
- Nitrogen is an essential nutrient for plants, but it is not readily available in a form that plants can absorb directly from the soil.

2. **Forms of Nitrogen:**
- There are various forms of nitrogen present in the soil, including:
- Atmospheric nitrogen (N₂)
- Ammonia (NH₃)
- Nitrate (NO₃⁻)
- Nitrite (NO₂⁻)

3. **Absorption of Nitrogen by Plants:**
- Plants cannot absorb atmospheric nitrogen directly. They rely on nitrogen that has been converted into a usable form through biological processes.

4. **Role of Bacteria:**
- Certain bacteria in the soil play a crucial role in converting nitrogen into forms that plants can use:
- **Nitrogen Fixation:** Some bacteria can convert atmospheric nitrogen into ammonia (NH₃).
- **Ammonification:** Organic nitrogen from decomposing matter is converted into ammonia by bacteria.
- **Nitrification:** Ammonia is further converted into nitrites (NO₂⁻) and then into nitrates (NO₃⁻) by nitrifying bacteria.

5. **Final Form of Nitrogen Absorbed by Plants:**
- The primary form of nitrogen that plants absorb from the soil is nitrate (NO₃⁻). This is the most readily available and usable form of nitrogen for plant uptake.

6. **Conclusion:**
- Therefore, the correct answer to the question is that the form of nitrogen from the soil that plants absorb is **nitrate (NO₃⁻)**.