What is your nitrogen footprint?

N-Print.org is a website focused on one of the main concerns of this website -- nitrogen pollution. They also have a nitrogen calculator! Worth a look: The human creation of reactive nitrogen (all N species except N2) by food and energy production has profound beneficial and detrimental impacts on people and the environment (1).  Agricultural uses, including both food production and consumption, contribute the most reactive nitrogen to the environment.  The main beneficial impact of the agricultural use of reactive nitrogen is the food produced by nitrogen fertilizer and human-enhanced biological nitrogen fixation.  These two processes provide the N to sustain about half of the world’s population (2).  The detrimental impacts result because a large fraction of the N used in food and biofuel production, and all of the N used in non-biofuel (i.e. non-agricultural) energy production, are lost to the environment.  Of the N used to produce food, about 80% is lost before consumption, and the remainder is lost after consumption as human waste.

Once lost to the environment, this nitrogen moves through the Earth’s atmosphere, forests, grasslands and waters causing a cascade of environmental changes that negatively impact both people and ecosystems.  These changes include smog, acid rain, forest dieback, coastal ‘dead zones’, biodiversity loss, stratospheric ozone depletion and an enhanced greenhouse effect (3).

The human influences on both the nitrogen and carbon cycles of the Earth are important to understand and to manage.  Over the past decade, great progress has been made in communicating to the public the role that their actions have on the carbon cycle and the environment.  For two reasons this is not the case with nitrogen.  First, there has been less scientific focus on nitrogen.  Second is the challenge in communicating to the public the complexities of nitrogen’s interactions with the environment.  One way to address the latter is through a nitrogen footprint model: N-Calculator....

A 42 foot Caterpillar Lexion combine harvester unloading wheat to an auger wagon pulled by a tracked Caterpillar Challenger tractor on the move near Pallamallawa, New South Wales, Australia. Shot by Cyron Ray Macey, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license