Research Project / Biochar Stability

Biochar can contribute to negative greenhouse gas emissions in the form of long-term carbon storage. It is important for the development of the biochar market to strengthen the knowledge around biochar stability in soils over long times and to develop ways of accounting for biochar stability.

This 4-year research project, named Biochar Stability: supporting transparent & reliable carbon removal, is funded by the Swedish Energy Agency.


The contact email of the project is: (the Swedish translation of “carbon storage to count on”).

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  • This webpage will be updated as the project goes


Biochar produced from biomass has large potential to provide negative greenhouse gas emissions as a stable carbon sink in soil. A major hurdle for biochar market establishment is the limited knowledge about the stability of biochar over longer time periods.

Update: a clarification statement (2023-06-15)

At the Biochar Summit in Helsinborg, we published a short non-technical statement synthesizing current knowledge on durability, resulting from 2 months of discussions between researchers in the field. Access it here:

Research objectives

  • Knowledge on biochar stability in Swedish agricultural soils
  • Field trials established for long-term evaluation of biochar stability
  • Open database for international research data on biochar stability
  • New models for calculation of biochar stability based on biochar properties and environmental conditions
  • Practical guidelines on how to use the stability models developed
 *Figure - Incubation equipment, biochar sample, and elemental composition chart*
Figure - Incubation equipment, biochar sample, and elemental composition chart

Timeline and work packages

The project has 5 work packages (WP):

  • WP1: Stakeholders & guidelines
  • WP2: Biochar characterisation
  • WP3: Laboratory incubations
  • WP4: Field trials
  • WP5: Data analysis

The project started in january 2022, and will continue until year 2025:

  • Year 2022: survey & roundtables with stakeholders (WP1) / biochar collection & characterisation (WP2) / experiment design (WP3-4) / litterature data collection, modelling toochain, and first re-analysis (WP5)
  • Year 2023: initial guidelines (WP1-5) / start of incubation (WP3) / start of field trials (WP4) / uncertainty modelling (WP5)
  • Year 2024: continued laboratory and field work (WP3-4)
  • Year 2025: update of guidelines (WP1-5)

The team

  • Cecilia Sundberg (SLU, energy and technology) Project leader.
  • Elias Azzi (SLU, PhD in biochar systems analysis) Data management & modelling of biochar stability in python.
  • Erik Karltun (SLU, lecturer in soil science at the Soil & Environment Department). Soil and plant interactions with biochar.
  • Harald Cederlund (SLU, molecular sciences) Researcher responsible for stability characterisation at the laboratory scale.
  • Haichao Li (SLU, Post-doctoral researcher, Soil & Environment Department) Responsible for laboratory and field incubations experiements.
  • Helena Söderqvist (2050 Consulting) Knowledge bridge between market & user.

Research outputs (dated 2022-06-08)

  • WP 5: A database schema to describe biochar stability incubation data was created. You can download it in machine readable format (JSON) or display it as a human readable HTML file (right click on the buttons below to open in a new tab)
    HTML Database Schema JSON Database Schema

  • WP 5: an interactive dashboard to explore the biochar stability incubation data, available here: