Soil Methane Meta-analysis
Citation: Jeffery S, Verheijen FGA, Kammann C, Abalos D (2016). Biochar effects on methane emissions from soils: A meta-analysis. Soil Biology and Biochemistry 101: 251–258. https://doi.org/10.1016/j.soilbio.2016.07.021 · author manuscript: https://hau.repository.guildhe.ac.uk/id/eprint/15223/1/Simon%20Jeffery%20biochar%20effects%20on%20methane%20emissions%2023%20July%2016%20upload.pdf
What it is: Meta-analysis of biochar effects on agricultural soil CH₄ fluxes, separating flooded vs non-flooded systems and soil pH classes. The vault’s primary CH₄ chapter source.
Key figures
| Figure | Value | Where | Check |
|---|---|---|---|
| Dataset | 62 studies screened → 42 included; 189 pairwise comparisons | Author PDF | ✓ full text |
| Metric | Hedge’s d | same | ✓ full text |
| Flooded soils | d = −0.87 (increased sink / reduced source) | Abstract / results | ✓ full text |
| Non-flooded soils | d = +0.65 (decreased sink / increased source) | Abstract / results | ✓ full text |
| Acidic soils (pH < 6) | d = −1.56 | Abstract / results | ✓ full text |
| Neutral soils | d = +1.17 | Abstract | ✓ full text |
| Alkaline soils | d = +0.44 | Abstract | ✓ full text |
Use with care
- Effect sizes are standardised mean differences, not percent reductions—don’t convert d to % without the paper’s own reporting.
- Sink/source ambiguity: a positive d can mean a weaker sink or a stronger source.
Related: Methane Fluxes · GHG Fluxes · Key Sources