Match the following columns:

Column I (Fertilisers)	Column II (N Content %)
a. Anhydrous ammonia	1. 16
b. Ammonium phosphate	2. 82
c. Di-ammonium phosphate	3. 18 - 21
d. Ammonium chloride	4. 25

a. N content in Anhydrous ammonia is 82%. Anhydrous ammonia, NH₃, is typically among the least expensive sources of nitrogen and contains 82 percent nitrogen by weight, the highest of all available sources.
b. N content in Ammonium Phosphate is 16%. Ammonium phosphate is an inorganic compound with the formula (NH₄)₃PO₄. It is the ammonium salt of orthophosphoric acid.
c. N content in Di-ammonium phosphate is 18 - 21%. DAP (NH₄)₂HPO₄: Fertilizer grade DAP Contains 18% Nitrogen and 46% Phosphorus (P₂O₅). DAP is manufactured by reacting Ammonia with Phosphoric acid under controlled conditions in fertilizer plants.
d. N content in Ammonium chloride is 25%. Ammonium chloride, a by-product of sodium bicarbonate production, contains 25 and 65% N and chlorine, respectively, and can be used as a nitrogen fertilization source in crops.