Boosting Nitrogen Efficiency: Key to Safeguarding Human Health and the Environment

A villager making biofuel from cow manure. The report says agrifood system policies should encourage the use of organic nitrogen fertilizers to enhance sustainability.
The rise in nitrogen fertilizers over the past century has significantly contributed to enhancing agricultural production and bolstering food security and nutrition for an expanding global population. Nevertheless, improper use of nitrogen can severely damage air, water, and soil quality, result in biodiversity loss, and exacerbate climate change.
A new report from the Food and Agriculture Organization of the United Nations (FAO), launched today, provides a comprehensive overview of nitrogen use and the resulting challenges in agrifood systems. It emphasizes the importance of ensuring sustainable use and offers recommendations to achieve this goal.
Nitrogen is an essential component of food constituents, particularly amino acids and proteins required for the growth of plants, animals, and humans.
Thanks to the invention of the Haber–Bosch process in the early 20th century, humans have been able to convert unreactive nitrogen, abundant in the atmosphere (the same nitrogen that makes the sky blue), into useful substances like ammonia, which is now commonly used as fertilizer.
Humans currently add approximately 150 teragrams (Tg) of reactive nitrogen to the Earth’s land surface each year through agriculture and industry. This amount is more than double the pre-industrial rate. Some experts suggest that climate change could contribute to this rate raising to about 600 Tg per year by 2100, which could increase the levels of nitrogen loss into the environment.
Livestock are the main contributors to nitrogen emissions and are responsible for about one-third of the total nitrogen emissions produced by human activity. Synthetic fertilizers, land-use change, and manure emissions are the main causes of nitrogen pollution in this area.
Nitrogen pollution is most severe in North America, Western Europe and certain Asian countries, where fertilizers have been extensively used and misused for decades.
In some low- and middle-income countries restricted access to fertilizers leads to the depletion of nitrogen, which reduces soil nutrients and leads to soil degradation.
A judicious use of nitrogen in agriculture, therefore, helps prevent soil degradation and nutrient depletion while increasing crop yields. In contrast, excessive use exacerbates global warming, degrades air and water quality, and depletes stratospheric ozone. Nitrogen pollution poses risks to human health by increasing the incidence of respiratory and heart diseases.
Therefore, sustainable nitrogen management that focuses on minimizing external inputs and losses and maximizing recycling is more urgent than ever.
“Nitrogen Use Efficiency (NUE) has seen improvements in recent years, which is encouraging. However, significant work remains to be done. This report provides a detailed set of recommendations to further enhance NUE, helping to reduce pollution while promoting environmental and human health,” stated Thanawat Tiensin, Assistant Director-General and Director of the Animal Production and Health Division at FAO.
The report highlights critical actions and policies to improve nitrogen use efficiency (NUE) globally, offering case studies and recommendations to address nitrogen-related challenges. Key proposals include reducing greenhouse gas emissions from nitrogen fertilizer production and minimizing waste throughout its lifecycle. Governments are urged to promote biological nitrogen fixation in crop rotations using legumes and establish manure management guidelines to reduce nitrogen losses.
The report advocates for sustainable agrifood policies, such as promoting organic fertilizers, spatial livestock planning, and circular bioeconomy practices. It emphasizes integrating nitrogen management into national climate and biodiversity strategies, reducing food waste, and encouraging recycling unsuitable food as livestock feed.
Private and public stakeholders are called to invest in efficient, low-emission fertilizers and recycling organic residues. Improved NUE, the report asserts, is essential for meeting Sustainable Development Goals by 2030, enhancing food production, reducing emissions, and protecting water and ecosystems while addressing global hunger and climate challenges.