en: Less ammonia from synthetic nitrogen fertilizers

Ammonia is an environmentally harmful gas. It mainly originates from agricultural fertilization. A new study shows which adaptations in synthetic fertilizers are most effective in reducing ammonia emissions.

Synthetic urea fertilizer with and without urease inhibitor.

Ammonia from agricultural fertilizers is harmful to ecosystems and human health. Regulations such as the fertiliser regulation are intended to reduce the release of the nitrogen-containing gas – with success. Since 2016 ammonia emissions have fallen by 65 percent after the use of synthetic nitrogen fertilizers in Germany.

A new study led by the Thünen Institute in cooperation with the Technical University of Munich now shows that two adaptations were particularly effective: the incorporation of the synthetic fertiliser into the soil and the addition of urease inhibitors. The latter ensure that less ammonia is released when fertilized with urea. The majority of the emission data on which the study is based comes from the Thünen Institute of Climate-smart Agriculture.

„The use of urease inhibitors could therefore be an important strategy for other countries in which the synthetic nitrogen fertilizer urea is the main cause of ammonia emissions“, explains Yuncai Hu, scientist at the Technical University of Munich.

The next important step is to apply the new findings to fertilization with liquid manure and fermentation residues because this is where 80 percent of ammonia emissions in Germany are generated.

Original publication:

Hu Y., Flessa H., Vos C., Fuss R., Schmidhalter U.: Successful NH3 abatement policies and regulations in German agriculture. Science of the Total Environment 956, 177362 (2024). https://doi.org/10.1016/j.scitotenv.2024.177362