More sustainable agriculture by global redistribution of nitrogen fertilizer

Models Reveal that a Homogeneous Global Distribution of Nitrogen Fertilizer Would Significantly Reduce Worldwide Fertilization and the Resulting Pollution of the EnvironmentModels Reveal that a Homogeneous Global Distribution of Nitrogen Fertilizer Would Significantly Reduce Worldwide Fertilization and the Resulting Pollution of the EnvironmentAbout 60 percent of worldwide nitrogen fertilizer consumption are presently used for growing crops, such as corn, wheat, or rice. These plants need nitrogen fertilizers to grow and produce bigger harvests. However, large quantities of the fertilizer enter the ground and groundwater or are emitted into the atmosphere in the form of nitrous oxide. This pollutes the environment and contributes to the loss of biological diversity, to climate change, and to the degradation of the ozone layer. This problem is particularly serious in the big cultivation areas of North America, Europe, and East Asia, where comparably large amounts of nitrogen fertilizer are used. KIT researchers recently modeled the effect of a worldwide redistribution of nitrogen fertilizer use. They simulated various fertilizer quantities at different locations and calculated the total production of corn, wheat, and rice between 2015 and 2030 using the biogeochemical model LandscapeDNDC. “Our work was based on the question of how we can produce sufficient food without exceeding environmental boundaries,” says Dr. Andrew Smerald from the Atmospheric Environmental Research Department of KIT’s Institute of Meteorology and Climate Research (IMK-IFU), KIT’s Campus Alpine in Garmisch-Partenkirchen.

Grain Production Level Could Be Maintained with a Far Smaller Global Use of Fertilizer

“Our models show that worldwide consumption of nitrogen fertilizer could be reduced by 32 percent by a more homogeneous distribution. The current level of grain production would remain unaffected,” Smerald says. “For this, nitrogen fertilizer would have to be redistributed from traditional cultivation areas in China, North America, and Europe to less used areas, such as Sub-Saharan Africa.“ Then, the increased production in these regions would compensate decreased production in other regions. As a result, nitrogen fertilizer use for wheat and corn production would be reduced by 45 and 33 percent, respectively, without influencing worldwide production quantities. Moreover, nitrate leaching would be reduced by 71 percent for wheat and 63 percent for corn.

Models reveal that worldwide redistribution of nitrogen fertilizer consumption would positively affect nitrous oxide emissions. (Photo: Andrew Smerald, KIT)

“According to our study, a more homogeneous distribution of nitrogen fertilizer across global croplands would reduce our dependence on the presently existing granaries and decrease nitrogen pollution in East Asia and other strongly fertilized regions,” Smerald says. Another advantage would consist in the fact that crops could be cultivated closer to the place of their consumption. Increased harvests in Africa would help the continent reach self-sufficiency.

Original Publication
Andrew Smerald, David Kraus, Jaber Rahimi, Kathrin Fuchs, Ralf Kiese, Klaus Butterbach-Bahl, & Clemens Scheer: A redistribution of nitrogen fertiliser across global croplands can help achieve food security within environmental boundaries. Communications Earth & Environment, 2023. DOI 10.1038/s43247-023-00970-8. https://www.nature.com/articles/s43247-023-00970-8

More about the KIT Climate and Environment Center

Being “The Research University in the Helmholtz Association”, KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility, and information. For this, about 9,800 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 22,300 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life. KIT is one of the German universities of excellence.

About 60 percent of worldwide nitrogen fertilizer consumption are presently used for growing crops, such as corn, wheat, or rice. These plants need nitrogen fertilizers to grow and produce bigger harvests. However, large quantities of the fertilizer enter the ground and groundwater or are emitted into the atmosphere in the form of nitrous oxide. This pollutes the environment and contributes to the loss of biological diversity, to climate change, and to the degradation of the ozone layer. This problem is particularly serious in the big cultivation areas of North America, Europe, and East Asia, where comparably large amounts of nitrogen fertilizer are used. KIT researchers recently modeled the effect of a worldwide redistribution of nitrogen fertilizer use. They simulated various fertilizer quantities at different locations and calculated the total production of corn, wheat, and rice between 2015 and 2030 using the biogeochemical model LandscapeDNDC. “Our work was based on the question of how we can produce sufficient food without exceeding environmental boundaries,” says Dr. Andrew Smerald from the Atmospheric Environmental Research Department of KIT’s Institute of Meteorology and Climate Research (IMK-IFU), KIT’s Campus Alpine in Garmisch-Partenkirchen.

Grain Production Level Could Be Maintained with a Far Smaller Global Use of Fertilizer

“Our models show that worldwide consumption of nitrogen fertilizer could be reduced by 32 percent by a more homogeneous distribution. The current level of grain production would remain unaffected,” Smerald says. “For this, nitrogen fertilizer would have to be redistributed from traditional cultivation areas in China, North America, and Europe to less used areas, such as Sub-Saharan Africa.“ Then, the increased production in these regions would compensate decreased production in other regions. As a result, nitrogen fertilizer use for wheat and corn production would be reduced by 45 and 33 percent, respectively, without influencing worldwide production quantities. Moreover, nitrate leaching would be reduced by 71 percent for wheat and 63 percent for corn.

“According to our study, a more homogeneous distribution of nitrogen fertilizer across global croplands would reduce our dependence on the presently existing granaries and decrease nitrogen pollution in East Asia and other strongly fertilized regions,” Smerald says. Another advantage would consist in the fact that crops could be cultivated closer to the place of their consumption. Increased harvests in Africa would help the continent reach self-sufficiency.

Original Publication
Andrew Smerald, David Kraus, Jaber Rahimi, Kathrin Fuchs, Ralf Kiese, Klaus Butterbach-Bahl, & Clemens Scheer: A redistribution of nitrogen fertiliser across global croplands can help achieve food security within environmental boundaries. Communications Earth & Environment, 2023. DOI 10.1038/s43247-023-00970-8. https://www.nature.com/articles/s43247-023-00970-8

More about the KIT Climate and Environment Center

Being “The Research University in the Helmholtz Association”, KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility, and information. For this, about 9,800 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 22,300 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life. KIT is one of the German universities of excellence.