Preserving the environment

Fertilizers are produced by extracting nitrogen from the atmosphere.

Optimizing fertilizer production

The process requires energy and thus releases CO2, contributing to global warming. Due to continuous improvements, European fertilizer plants are today operating near the theoretical energy minimum and Yara plants are among the best in the world. 

In addition to CO2, fertilizer production also releases N2O, a powerful green house gas. Yara has developed proprietary catalyst technology to abate most of the N2O released during production. As a forerunner in the industry, Yara is sharing its catalyst technology with other fertilizer producers around the world. The climate impact of fertilizers can be measured by its carbon footprint. It is expressed as kg CO2-eqv per kg nitrogen produced. However, to understand the true climate impact of a product, lifecycle analysis needs to be performed, including all steps from production to application. A detailed comparison of the respective life cycle carbon footprints for different fertilizer types are given in the next section.

Energy consumption of European fertilizer production plants has decreased over time and is today near the theoretical optimum.

Yara has reduced the carbon footprint of nitrate fertilizer production by 35- 40%. Enhancing nitrogen efficiency in fertilizer use can contribute by another 10-30%.

Improving fertilizer application

The undesirable environmental effects of fertilizer application, whether from mineral or organic sources, are not caused by any fundamental properties of these elements but as a result of lost nitrogen. Where such losses are kept small, the negative effects on the environment are also minimal.

Average ammonia emissions per kg of nitrogen applied for different fertilizer types. The table includes data from the official European Emission Inventory EMEP as well as the Defra study. In all cases, volatilization losses are significantly higher with urea and UAN than with (calcium) ammonium nitrate.

The life cycle carbon footprint for ammonium nitrate is lower than for urea and UAN. When compensating the lower efficiency of urea and UAN by higher dosage, the difference is even more marked.

The residual nitrogen in the soil after harvesting, and thus the risk of leaching, is not increasing for application rates below optimum N supply.

Assessing overall environmental performance

The different environmental effects of fertilizer production and application (land use, eutrophication of land and water, global warming and acidification) can be aggregated into the so-called environmental index EcoX. The index measures the environmental burden based on a life cycle analysis. All burdens are then compared to European targets, weighted and added. The higher the resulting figure, the higher the environmental burden. Ammonium nitrate offers the lowest environmental index.