COMBI Soil Quality Review
Citation: Antonangelo JA, Sun X, Zhang H (2021). The roles of co-composted biochar (COMBI) in improving soil quality, crop productivity, and toxic metal amelioration. Journal of Environmental Management 277: 111443. https://doi.org/10.1016/j.jenvman.2020.111443
What it is: A narrative review of co-composted biochar (“COMBI”, biochar added at the start of composting). It covers production, soil and yield effects, and cleanup of soils contaminated with toxic metals.
Key figures
| Figure | Value | Where | Check |
|---|---|---|---|
| Definition | COMBI = biochar added at the beginning of composting | Abstract | ✓ abstract |
| Headline conclusion | COMBI beats using compost and biochar separately, or mixing them after composting | Abstract | ✓ abstract |
| Yield | Increases of up to 300% in some particular cases | Abstract | ✓ abstract |
| Evidence base | Research on producing and using COMBI is still limited | Abstract | ✓ abstract |
| Optimal loading of 10–15% w/w | Used in Biochar Inoculation for Fertilizer and Biochar Compost and Manure Blends | — | not re-checked (full text not accessible) |
| Woody or crop-residue chars made at 400–700 °C suit COMBI | Used in Biochar Inoculation for Fertilizer | — | not re-checked (full text not accessible) |
Use with care
- This is a review, not a meta-analysis: “up to 300%” is a best case from individual studies, not an average.
- Check the loading and temperature ranges above against the full text before quoting them as this paper’s recommendations.
Related: Biochar Compost and Manure Blends · shows co-compost nitrate capture · Key Sources