Quick facts
About 78% of the atmosphere is inert dinitrogenAir is mostly N2
Only some bacteria and archaea fix N2 into ammoniaNitrogenase
1909–1913 industrial ammonia — a human parallel to microbesHaber-Bosch
Ammonia oxidisers then nitrite oxidisers (classic Nitrosomonas / Nitrobacter teaching)Nitrification pair
Anaerobes return N2 (and some N2O) to airDenitrification
1990s — anaerobic ammonium oxidation, now used in some wastewater plantsAnammox
The nitrogen cycle is how life borrows an inert atmospheric gas. Microbes fix N2, oxidise ammonia, and return N2 — a relay no animal invented.
Haber-Bosch (1909–1913) added an industrial shortcut that now feeds billions and also leaks surplus nitrate and N2O.
This atlas is ecology and history, not a fertilizer recipe or a culture protocol.
The profile
- Familiarity40
- Medical weight10
- Benefit90
- Risk8
- Research60
- Live debate15
Risk
How microbes move nitrogen between air, soil, water and food — plus the industrial shortcut that feeds billions.
Seven ways into this topic
01
Identity
A microbial relay that moves nitrogen between air, water, soil and living tissue.
Read ?
02
How they live
Fixation, assimilation, nitrification, denitrification and anammox.
Read ?
03
Body & health
Bread from Haber-Bosch, river dead zones, and wastewater as a microbial factory.
Read ?
04
History
From Hellriegel's nodules to Haber-Bosch, Winogradsky and anammox.
Read ?
05
Everyday life
Beans on the plate, lawn fertilizer, river news and the air you do not notice.
Read ?
06
Frontiers
How to feed people with less leak, and who the newest oxidisers really are.
Read ?
07
Myths
Air nitrogen is not plant food until microbes or factories act; more fertilizer is not always better.
Read ?
Frequently asked questions
Why can't we breathe nitrogen into protein?
N2's triple bond is extremely stable. Only nitrogenase (and industry) break it at scale.
Do plants fix nitrogen themselves?
Most do not. Legumes host rhizobia in nodules. Some other plants host different partners.
Is Haber-Bosch a microbe?
No. It is an industrial chemical process that now rivals biological fixation in global flux.
What is nitrification?
Microbes oxidise ammonia to nitrite then nitrate — a teaching two-step, now known to include complete ammonia oxidisers too.
Is this fertilizer advice?
No. Educational only. Farm rates belong with agronomists.
Can I culture nitrogen-fixers at home?
This atlas does not provide culture methods.
Why does the cycle matter for climate?
N2O is a strong greenhouse gas from soils and waters. Amounts depend on oxygen and surplus nitrogen.
Is this medical advice?
No. Educational only.
More in Beneficial allies
