Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment

Abstract

Nitrogen (N) management presents a sustainability dilemma: N is strongly linked to energy and food production, but excess reactive N causes environmental pollution. The N footprint is an indicator that quantifies reactive N losses to the environment from consumption and production of food and the use of energy. The average per capita N footprint (calculated using the N-Calculator methodology) of ten countries varies from 15 to 47 kg N capita -1 year -1 . The major cause of the difference is the protein consumption rates and food production N losses. The food sector dominates all countries' N footprints. Global connections via trade significantly affect the N footprint in countries that rely on imported foods and feeds. The authors present N footprint reduction strategies (e.g., improve N use efficiency, increase N recycling, reduce food waste, shift dietary choices) and identify knowledge gaps (e.g., the N footprint from nonfood goods and soil N process).

Variations in the Use of Resources for Food: Land, Nitrogen Fertilizer and Food Nexus

“…Other studies show the nitrogen footprint of food using the Nitrogen Calculator (a website designed for consumers to calculate their N footprint: www.n-print.org). The values for Mexico range from 20 to 50 kg·N/cap/year [19] and for Tanzania it is 14 kg·N/cap/year [21]. These comparisons show that our results are in the same order of magnitude as the present literature, and the differences are due to our simplifications and the fact that we only considered the use of synthetic nitrogen fertilizer in order to discuss the trade-off between the use of nitrogen fertilizer and land.…”

“…Other studies have calculated all sources of nitrogen related with food production and consumption [19][20][21]. In contrast, in this paper, we are interested in the trade-off between arable land use and synthetic nitrogen fertilizer; therefore, we only consider the use of synthetic nitrogen fertilizer for the production of the food.…”

High nitrogen rates do not increase canola yield and may affect soil bacterial functioning

“…Inorganic N fertilizer application is a primary approach to intensify crop production and ensure food security (Liu et al., ), but it also has a large C footprint and causes eutrophication and algal blooms when it leaches from agricultural land to waterways (Seitzinger & Phillips, ). In addition, fuel and energy use during the manufacturing and transport processes of fertilizers may also contribute substantially to environmental erosion (Shibata et al., ). Although N fertilization has a fundamental role in agricultural productivity, it is important to ensure the minimum N required for satisfactory crop growth is applied.…”

Opportunities and Barriers for Water Co-Governance—A Critical Analysis of Seven Cases of Diffuse Water Pollution from Agriculture in Europe, Australia and North America

“…It constitutes a threat to water quality and aquatic ecosystems in many farmed regions of the world [1][2][3][4][5][6][7]. Information regarding DWPA is incomplete and asymmetrical; the polluters often have more information than the regulators [8].…”