Editing Nitrogen fixation (section)

=== Haber process ===
{{Main|Haber process}}
[[File:THC 2003.902.022 D. C. Bardwell Study of Nitrogen Fixation.tif|thumb|right|Equipment for a study of nitrogen fixation by [[alpha ray]]s (Fixed Nitrogen Research Laboratory, 1926)]]
The dominant industrial method for producing ammonia is the [[Haber process]] also known as the Haber-Bosch process.<ref>Smil, V. 2004. Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production, MIT Press.</ref> Fertilizer production is now the largest source of human-produced fixed nitrogen in the terrestrial [[ecosystem]]. Ammonia is a required precursor to [[fertilizer]]s, [[explosive]]s, and other products. The Haber process requires high pressures (around 200 atm) and high temperatures (at least 400&nbsp;°C), which are routine conditions for industrial catalysis. This process uses natural gas as a hydrogen source and air as a nitrogen source. The ammonia product has resulted in an intensification of nitrogen fertilizer globally<ref>{{Cite journal| vauthors = Glibert PM, Maranger R, Sobota DJ, Bouwman L |author-link1=Patricia Glibert |author-link2=Roxane Maranger |date=2014-10-01|title=The Haber Bosch–harmful algal bloom (HB–HAB) link|journal=Environmental Research Letters|volume=9|issue=10|pages=105001|doi=10.1088/1748-9326/9/10/105001|bibcode=2014ERL.....9j5001G|s2cid=154724892 |issn=1748-9326|doi-access=free}}</ref> and is credited with supporting the expansion of the human population from around 2 billion in the early 20th century to roughly 8 billion people now.<ref>{{Cite journal| vauthors = Erisman JW, Sutton MA, Galloway J, Klimont Z, Winiwarter W |date=October 2008|title=How a century of ammonia synthesis changed the world |journal=Nature Geoscience|language=en|volume=1|issue=10|pages=636–639|doi=10.1038/ngeo325|bibcode=2008NatGe...1..636E|s2cid=94880859 |issn=1752-0908}}</ref>