Editing Nitrate (section)

== Occurrence and production ==
Nitrate salts are found naturally on earth in arid environments as large deposits, particularly of [[nitratine]], a major source of [[sodium nitrate]].

Nitrates are produced by a number of species of [[nitrifying bacteria]] in the natural environment using [[ammonia]] or [[urea]] as a source of nitrogen and source of free energy. Nitrate compounds for [[gunpowder]] were historically produced, in the absence of mineral nitrate sources, by means of various [[industrial fermentation|fermentation]] processes using urine and dung.

Lightning strikes in earth's nitrogen- and oxygen-rich atmosphere produce a mixture of oxides of nitrogen, which form [[Nitrous acid|nitrous]] ions and nitrate ions, which are washed from the atmosphere by rain or in [[Precipitation#occult deposition|occult deposition]].

Nitrates are produced industrially from [[nitric acid]].<ref name=Ullmann/>