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Cascading through the environment
Figure 1: The nitrogen cascade
A single atom of nitrogen can have sequential effects in various parts of the environment after it has been converted from non-reactive N2 to a reactive form during energy or food production.
There are three groups of reactive nitrogen compounds:
inorganic reduced forms of N: ammonia [NH3] and others forms [NHx], such as ammonium [NH4+];
inorganic oxidized forms: nitrogen oxide [NOx], nitrous oxide [N2O], nitrate [NO3-] and others [NOy]; and
organic compounds: urea, amines, proteins, nucleic acids and others [Norganic]
Source: adapted from Galloway and others 2003 and redrawn by Robert Smith, Charlottesville, US


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