<P> Human impact on the nitrogen cycle is diverse . Agricultural and industrial nitrogen ( N ) inputs to the environment currently exceed inputs from natural N fixation . As a consequence of anthropogenic inputs , the global nitrogen cycle ( Fig. 1 ) has been significantly altered over the past century . Global atmospheric nitrous oxide ( N O ) mole fractions have increased from a pre-industrial value of ~ 270 nmol / mol to ~ 319 nmol / mol in 2005 . Human activities account for over one - third of N O emissions , most of which are due to the agricultural sector . This article is intended to give a brief review of the history of anthropogenic N inputs , and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems . </P>
<P> Human impact on the nitrogen cycle is diverse . Agricultural and industrial nitrogen ( N ) inputs to the environment currently exceed inputs from natural N fixation . As a consequence of anthropogenic inputs , the global nitrogen cycle ( Fig. 1 ) has been significantly altered over the past century . Global atmospheric nitrous oxide ( N O ) mole fractions have increased from a pre-industrial value of ~ 270 nmol / mol to ~ 319 nmol / mol in 2005 . Human activities account for over one - third of N O emissions , most of which are due to the agricultural sector . This article is intended to give a brief review of the history of anthropogenic N inputs , and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems . </P>
human interaction with the nitrogen cycle is primarily due to
human interaction with the nitrogen cycle is primarily due to
the agricultural sector
the agricultural sector