What is the nitrogen footprint of organic food in the United States?

Laura Cattell Noll1, Allison M. Leach2, Verena Seufert3, James N. Galloway1, Brooke Atwell1, Jan Willem Erisman4, Jessica Shade5

1 University of Virginia, 291 McCormick Rd, Charlottesville, VA, 22903, http://www.virginia.edu/, 22903 USA, [email protected]

2 University of New Hampshire, 131 Main Street, 107 Nesmith Hall, Durham, NH, 03824 USA

3 University of British Columbia, 6476 NW Marine Drive, Vancouver, BC, V6T 1Z2, Canada

4 Louis Bolk Institute, Hoofdstraat 24, 3972 LA, The Netherlands; VU Amsterdam, The Netherlands

5 The Organic Center, 444 N. Capitol St. NW, Suite 445, Washington D.C. 20001 USA

Abstract

Using a nitrogen (N) footprint model, we estimated the Nr lost per unit Nr consumed for organic food production in the United States and compared it to conventional production. Additionally, we quantified the types of Nr inputs (new versus recycled) that are used in both production systems.

Nr losses from organic crop and animal production are estimated to be of comparable magnitude to conventional production losses. While Nr losses from organic grains and vegetables are slightly higher (+13%, +43%, respectively), and from organic starchy roots and legumes slightly lower (-1%, -17% respectively), losses from organic poultry, pigmeat, beef and dairy production are generally higher than from conventional production (+40%, -7%, +58%, +81%, respectively). Due to high variability and high uncertainty in both systems, we cannot make conclusions yet on the significance of these differences. Conventional production relies heavily on the creation of new Nr (70-90% of inputs) whereas organic production primarily utilizes already existing Nr (0-50% of inputs from new Nr).

Consuming organically produced foods has little impact on an individual’s food N footprint, but it changes the percentage of new Nr in the footprint. Per unit N in product, Nr losses from organic production are comparable to conventional production, but organic production introduces less new Nr to the global pool.

For the full paper, please contact Laura Cattell Noll at [email protected]