Individual N footprints are Country-Specific:
The N-Calculator tool is country-specific to account for energy use, food consumption patterns, and food production practices specific to a particular country. The N-Calculator is currently available online for the United States, Netherlands, Germany, and United Kingdom. Versions for Austria and Japan will be posted in the coming months. Tools are in development for Australia, China, Denmark, Tanzania, and more!
The figure below from (Leach et al. 2013) shows a comparison of the nitrogen footprints currently available, along with preliminary results for Austria, Japan, and China. The footprints are then broken up into consumption sectors: food consumption, food production, housing, transport, and goods & services.
In all countries, the largest losses of nitrogen to the environment occur in the food sector, and in particular, food production. For the food consumption footprint, the difference across countries is not due to consumption rates--it is due to the advanced sewage treatment found throughout most of Germany, the Netherlands, and Austria. The differences in food production footprints are largely driven by food choice. For example, the Netherlands food production N footprint is smaller than that of the US due to lower consumption of meat; more of the protein consumed in the Netherlands is from fish and dairy. These country comparisons illustrate how lifestyle choices can minimize your N footprint.
The energy sector is typically the smallest part of an individual's nitrogen footprint. However, its contribution varies by country; in the United States, the energy footprint is proportionally larger. The US energy N footprint is driven by both higher rates of consumption (e.g., of gasoline) and higher emission factors.
Who is using the N-Calculator?
The figure below shows results from the N-Calculator for individuals based on their home country, as of late 2011 (Leach et al., 2012). This figure will be updated with more recent statistics. The numbers in parentheses show how many times the N-Calculator has been used by an individual from a particular country. For example, at the time of this figure, the N-Calculator had been used in Italy 1,231 times.