TRACES: Working towards safe and sustainable use of biochar in agriculture

 In Danish

Project period: 2026–2029

Supported by: LBST – Climate Research in Agriculture

In TRACES we are building a robust knowledge base for risk assessment of the environmental effects of biochar, so that biochar can be used safely and in a targeted way in Danish agriculture and the green transition.

Biochar is highlighted as an important tool to:

• Store carbon in the soil

• Improve soil quality and structure

• Reduce greenhouse gas emissions

But for the technology to be implemented responsibly on a large scale, systematic knowledge is needed about possible negative side effects.

_{Photo: From the first brainstorming sessions, we are working to combine our broad range of expertise and advanced test facilities.}

Central knowledge for key stakeholders

The project delivers knowledge that is essential for agriculture, public authorities and the utilities sector. It will give the agricultural sector a better understanding of how biochar can be used to store carbon and reduce emissions without increasing the risk of soil and water pollution. The utilities sector will obtain documentation on how residual biomass can be converted into safe products for agricultural use. At the same time, public authorities will gain a research-based foundation for decisions on legislation concerning biochar and biochar-based products.

TRACES focuses on the content, release and leaching potential of heavy metals, PFAS, nitrate and other harmful compounds from the investigated types of biochar in different soils. In addition, the project examines whether the biochar particles themselves are transported to deeper soil layers and drainage water.

We are responsible for:

• Mesocosm experiments: Controlled mini “field trials” in which we simulate, for example, real-world water conditions to see how the addition of biochar to soil affects the leaching of environmental contaminants in columns.

• Sorption experiments: Laboratory trials where we test how well biochar can bind – and potentially release – environmental contaminants to the soil.

The combination of laboratory experiments and mesocosm studies provides a strong basis for assessing the safety, risks and potential benefits of using biochar at field scale.

_{Photo: This is the mesocosm laboratory where we will be conducting the mesocosm experiments.}

Project partners

• University of Copenhagen (project lead)

• DTU

• SEGES