The characteristics of ammonium sulphate are:
(A). Ammonium sulphate \([(\text{NH}_4)_2\text{SO_4]\) is a white crystalline and free-flowing fertilizer.
(B). It contains only 20.5% N and classified as low analysis fertilizer and also contains 23.7% S.
(C). It is the best N-fertilizer having least hygroscopicity, indicating that it has excellent physical property.
(D). It is an excellent nitrogenous fertilizer for acid soil.
Choose the correct answer from the options given below:
Show Hint
Ammonium sulphate is a physiologically acid-forming fertilizer. It is highly suitable for alkaline and neutral soils, but is not recommended for acidic soils.
Step 1: Understanding the Concept:
Ammonium sulphate is an inorganic salt widely used as a nitrogen and sulphur fertilizer. Its properties determine its storage stability and suitability for different soil types. Step 2: Detailed Explanation:
- Statement A is correct: Pure ammonium sulphate is a white crystalline solid that is free-flowing and easy to handle.
- Statement B is correct: It contains \(20.5\%\) to \(20.6\%\) Nitrogen and approximately \(23.7\%\) to \(24\%\) Sulphur. Because its total primary nutrient concentration is less than \(25\%\), it is classified as a low-analysis fertilizer.
- Statement C is correct: It has low hygroscopicity (critical relative humidity of \(79\%\) at \(30^\circ\text{C}\)), which minimizes moisture absorption from the air during storage.
- Statement D is incorrect: Ammonium sulphate is a physiologically acid-forming fertilizer. When applied to soil, nitrification of \(\text{NH}_4^+\) releases hydrogen ions (\(\text{H}^+\)), which increases soil acidity. Thus, it is not recommended for acid soils as it further reduces soil pH.
- Consequently, statements (A), (B), and (C) are correct. Step 3: Final Answer:
The correct combination is (A), (B) and (C) only.
