Abstract:
Food production and power generation have increased to feed growing
populations and to keep pace with economic development, leading to major human
alteration of the global nitrogen (N) cycle. The result is a global challenge, with
many regions having ‘too much’ or ‘too little’ nitrogen. As di-nitrogen (N2) in the
atmosphere, nitrogen is one of the most abundant elements, but which cannot be used by most organisms. Conversely, reactive nitrogen (Nr) is essential for organisms, but
is mostly in short supply for natural ecosystems. Human activities have polarized the
differences in Nr flows between different world regions, leading to major sustainability challenges, with implications for food security, adverse impacts on health and
ecosystems, and the need to develop tools and policies for better management. In
developed regions, abundant use of manufactured fertilizers, crop biological nitrogen
fixation and inadvertent formation of nitrogen oxides via combustion processes are
leading to a plethora of environmental problems.