1. The Nitrogen Cycle Vinny Hageman and Kevin Lombardo

2. Found in animal waste and minerals • Present in all living organisms Nitrogen

3. Biological • Atmospheric nitrogen is converted to ammonia • Nitrogenase (enzyme) • Cyanobacteria • Chemical • Haber process • Requires high pressures/temperatures • Uses natural gas as a hydrogen source/ air as a nitrogen source Nitrogen Fixation

4. Nitrogen Cycle

5. Process of making nitrogen compounds in the air available to plants • Nitrogenase, cyanobacteria • Molecular nitrogen (N2) -> ammonia, nitrates, nitrites (NH4, NH3) Nitrogen Fixation

6. Conversion of ammonia to nitrates and nitrites • Nitrifying bacteria • Ammonia -> nitrates, nitrites Nitrification

7. Process during which decomposers convert organic nitrogen of dead plants into inorganic forms • Ex. Earthworms, bacteria, fungi Ammonification (Mineralization)

8. Process of reduction of nitrate to nitrogen • Microorganisms • Can lead to intermediates • Ex. Nitrous oxide Denitrification

9. Emissions of NO/NO2 from technical combustion processes • Ex. Car engines • High concentrations can lead to ozone smog • Nitrogen oxides -> nitric acid in atmosphere • Contributes to acid rain • Too much nitrogen-containing fertilizer in the soil • Ammonia and nitrate end up in water bodies and coastal areas and cause plant growth • Plant decomposition can fatally reduce oxygen content in water • Denitrification is enhanced and more nitrous oxide is produced • Increases greenhouse effect Human Intervention