Using biogas residues to mitigate agricultural nitrogen pollution

Explaining their research in less than 90 seconds: 8 young researchers from Luxembourg took up the challenge in the 2nd edition of the video series "My research in 90 seconds". In this episode, Bella Tsachidou talks about the possibility to use biogas residues to improve agronomic performance and mitigate environmental pollution! More about this in the video - and further details in her article.

The video and the accompanying article were produced as part of a “Science Communication Course” for PhD students at the University of Luxembourg.

Author: Bella Tsachidou (PhD at LIST)
Editor: Michelle Schaltz (FNR)
Video: Jean-Paul Bertemes (FNR) & Moast Creative Studios

Why is this study important?

As the world population grows, crop yields need to be increased to provide sufficient quantities of food and feed. To meet this challenge, the farming system has to overcome limiting factors such as nutrient depletion of arable soils. Nitrogen being the main mineral element required for plant growth, has led to its industrial fixation and extensive use in the form of chemical fertilizers. As a result, the nitrogen cycle has been greatly modified, causing nitrogen pollution of the aquatic and terrestrial ecosystems, as well as atmospheric contamination.

Recycling organic wastes for sustainable agriculture

To prevent further acceleration of environmental pollution caused by nitrogen from agricultural sources, and at the same time integrate the biogas sector into the new bio-economy, we propose the recycling of anaerobically digested organic wastes from various sources such as agriculture, food/feed industries, households and more, back to arable lands. Anaerobic digestion is an eco-friendly and cost competitive multipurpose process that generates both biogas and biogas residues. The residues produced are not a waste but a valuable co-product, which contains all the nutrients initially present in the substrate, and therefore can be used as biofertilizer for the agricultural soils. Even though the residues from the biomethanation process are a new type of organic fertilizer, there is a considerable number of research publications that highlight their beneficial effects on soil [1] and plants [2]. Moreover, the on-farm anaerobic digestion of readily available organic resources can cover the demands of the farm in heat and power.

What is the aim of the study?

Within the framework of the «Persephone» Project, field trials of 17 different fertilisation schemes are in place across the grasslands of the Greater Region. The overarching purpose of the study is to investigate the contribution of biogas residues to the mitigation of nitrate leaching in the soil, and their impact on agronomic performance and soil microbial community composition, function and nitrogen cycling capacity. Another aim is to demonstrate, on one hand, the rampant polluting nature of chemical fertilizers, and on the other hand, the environmental benefits resulting from their substitution by biogas residues. Overall, this research aims to mitigate the environmental pollution by reducing the production and use of chemical fertilizers and by influencing the policy makers to promote biogas residues as a sustainable alternative for the agriculture.

For further questions please contact:

Bella Tsachidou
Luxembourg Institute of Science & Technology (LIST),
Environmental Research & Innovation Department
Tel: +352 470 261 5033
Email: bella.tsachidou@list.lu