Question

Which of the following purposes N - serve is used?

• A. Phosphate solubility
• B. Nitrification inhibitor
• C. Chelating agent
• D. Urease inhibiter

Hint:

Remember the classic nitrification inhibitors:
- Nitrapyrin (N-Serve)
- DCD (Dicyandiamide)
- AM (2-amino-4-chloro-6-methylpyrimidine)
Keep these names memorized for nutrient management questions.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Nitrogen fertilizers applied to soil are subject to significant losses through leaching (as nitrate, \(\text{NO}_3^-\)) and denitrification (as nitrous oxide, \(\text{N}_2\text{O}\), and nitrogen gas, \(\text{N}_2\)).
Chemical compounds are developed to temporarily halt or slow down specific steps in the nitrogen cycle to minimize these losses.

Step 2: Detailed Explanation:
"N-Serve" is the registered commercial trade name for Nitrapyrin (2-chloro-6-(trichloromethyl)pyridine).
It is a widely used, highly effective nitrification inhibitor.
The primary mode of action of Nitrapyrin includes:
- It selectively inhibits the activity of soil bacteria belonging to the genus Nitrosomonas.
- These bacteria are responsible for the first step of nitrification, which oxidizes ammonium (\(\text{NH}_4^+\)) to nitrite (\(\text{NO}_2^-\)):
\[ 2\text{NH}_4^+ + 3\text{O}_2 \xrightarrow{\textit{Nitrosomonas}} 2\text{NO}_2^- + 2\text{H}_2\text{O} + 4\text{H}^+ \]
By temporarily suppressing these bacteria, Nitrapyrin keeps nitrogen in the stable ammonium (\(\text{NH}_4^+\)) form for longer.
Ammonium is positively charged and binds to negatively charged soil clay and organic matter, preventing it from leaching.
This reduces nitrate accumulation in groundwater and lowers nitrous oxide emissions, thereby improving nitrogen use efficiency.

Step 3: Final Answer:
N-serve is used as a Nitrification inhibitor.