As with metal ores, it is useful to be able to calculate exactly what proportion the essential nutrients accounts for in a fertiliser. Ammonium nitrate (NH 4 NO 3) is commonly used as a fertiliser.

Nitrate fertilisers can be made through neutralisation reactions. To complete this, a supply of nitric acid is required. Nitric acid is then used to make ammonium nitrate which is high in nitrogen.

Syria’s new authorities have started probing “the involvement of the former Syrian regime in cooperation with Iran-backed Lebanese militias” in “the import and smuggling of the ammonium nitrate” of ...