Phosphorus in DAP is

Correct option is D

The correct answer is (D) 46%

Explanation:
• DAP (Diammonium Phosphate) is the most widely used phosphatic fertilizer in the world. It is a concentrated, high-analysis fertilizer.
• The standard grade of DAP contains 18% Nitrogen (in ammoniacal form) and 46% Phosphorus (as $P_2O_5$).
• Most of the phosphorus in DAP ($>90%$) is water-soluble, making it highly effective for providing immediate $P$ to crops during the early growth stages.
• Its chemical formula is $(NH_4)_2HPO_4$. Because it contains both Nitrogen and Phosphorus, it is classified as a "Complex" or "Binary" fertilizer.

Information Booster:
• SSP (Single Super Phosphate): Contains $16% P_2O_5$ and is also a source of Sulfur ($12%$).
• Urea: The most common Nitrogenous fertilizer, containing $46% N$.
• MOP (Muriate of Potash): Contains $60% K_2O$.
• DAP should not be mixed with lime or high-calcium fertilizers as it can lead to phosphorus fixation.

Additional Knowledge:
• Option C (18%): This is the percentage of Nitrogen in DAP, not phosphorus.
• Option B (60%): This is the percentage of Potassium in MOP.
• DAP has an alkaline reaction around the dissolving granule, which can temporarily damage seeds if placed too close, but overall it has an acid-forming effect on soil in the long run.