Background Information
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.
The Nitrogen Cascade
The video below, developed by Erin Siegel and Professor Myrna Jacobson Meyer at the University of Southern California, describes how nitrogen cascades through the environment and the widespread effect a single atom of reactive nitrogen can have on various parts of the environment.
About the N-PRINT Team
The team behind the N-PRINT project is made up of nitrogen researchers from many organizations:
James Galloway and Allison Leach from the University of Virginia
Albert Bleeker and Jan Willem Erisman from the Energy Research Center of the Netherlands
Richard Kohn from the University of Maryland
N-PRINT is an INI (International Nitrogen Initiative) project. INI strives to both "minimize the negative effects of nitrogen on human health and the environment" and "optimize the beneficial role of nitrogen in sustainable food production."
The North American Nitrogen Center is one of five globally distributed centers of the INI. Their website provides more information on nitrogen and projects related to nitrogen in the US.
If you have any questions, you can contact Alley Leach via e-mail (aml4x@virginia.edu) or phone (1-434-924-1303).
Please also feel free to contact us here with questions.
Further reading on nitrogen
1. A nitrogen footprint model to help consumers understand their role in nitrogen losses to the environment. Leach, AM, JN Galloway, A Bleeker, JW Erisman, R Kohn, J Kitzes. In press. Environmental Development.
2. Transformation of the nitrogen cycle: recent trends, questions and potential solutions. Galloway, JN, AR Townsend, JW Erisman, M Bekunda, Z Cai, JR Freney, LA Martinelli, SP Seitzinger, MA Sutton. 2008. Science 320, 889-892.
3. How a century of ammonia synthesis changed the world. Erisman, JW, JN Galloway, MA Sutton, Z Klimont, W Winiwarter. 2008. Nature Geocience 1, 636-639.
4. The nitrogen cascade. Galloway, JN, JD Aber, JW Erisman, SP Seitzinger, RW Howarth, EB Cowling, BJ Cosby. 2003. Bioscience 53, 341-356.
4. Too much of a good thing. Sutton, MA, O Oenema, JW Erisman, A Leip, H van Grinsven, W Winiwarter. 2011. Nature 472, 159-161.
5. Advances in nitrogen management for water quality. Delgado, JA and RF Follett (eds). 2010. 424 pp. Soil and Water Conservation Society. Ankeny, IA.
6. Nitrogen in agricultural systems. Schepers, JS, and WR Raun (eds). 2008. Agronomy Monograph 9. 965 pp. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. Madison, WI.
7. Agirculture and the nitrogen cycle: Assessing the impacts of fertilizer use on food production and the environment. Mosier, AR, JK Syers, and JR Freney (eds). 2004. 296 pp. SCOPE 65, Island Press. Washington, DC.
8. Nitrogen in the environment: Sources, problems, and management. Follett, RF, and JL Hatfield. 2001. 520 pp. Elsevier.
You can also visit www.NitrogenNews.com for the latest news in the nitrogen world.
