
Shifting some use of nitrogen from rich countries to poor countries would improve food security and environmental sustainability, according to a study. Wealthy countries tend to use too much nitrogen fertilizer, which leads to climate change, water pollution, and biodiversity degradation.
Poor countries lack sufficient nitrogen to attain proper crop yields. Helena Kahiluoto and colleagues quantified the optimal redistribution of nitrogen input for production of maize, rice, and wheat among countries and sub-national regions, using a set of nitrogen-yield response functions from an ensemble of empirically evaluated global gridded crop models.
The authors modeled production for both the current level of nitrogen use and for lower levels deemed sustainable. In addition, the authors modeled the lowest possible use of nitrogen to achieve today’s level of food production. Optimal redistribution of today’s level of nitrogen use would increase global crop production by 12%.