From N₂ gas to amino acids — bacteria power the cycle that feeds the world
Nitrogen Pools (Tg N)
Atmosphere N₂—
Soil Inorganic (NO₃⁻/NH₄⁺)—
Living Biomass—
Ocean—
Industrial Fixed (Haber)—
Human Interventions
Haber-Bosch Process Industrial N fixation (120 Tg/yr)
Fossil Fuel NOₓ Combustion N deposition
Livestock Manure NH₃ volatilization
Human activity has roughly DOUBLED the rate of reactive N creation. Excess N causes: eutrophication, acid rain, N₂O (greenhouse gas, ozone depleter), biodiversity loss.