Ansari et al. (2026): Rock-enhanced biochar exhibits similar priming effect as pure biochar application while improving short-term carbon stabilization in agricultural soils

Maria Ansari, Annemarie Lübeck, Johannes Meyer zu Drewer, Nikolas Hagemann, Annette Eschenbach and Joscha N. Becker, IN: Biology and Fertility of Soils, https://doi.org/10.1007/s00374-026-02030-7

Combined application of biochar and silicate rock powder might have synergistic effects on carbon dioxide removal and soil improvement. However, it remains unknown how their combination affects mineralization and stabilization of soil organic carbon (SOC). The authors compared pure 13C-labeled wheat-straw biochar, pure basanite rock powder, their co-application, and rock-enhanced biochar from co-pyrolysis of wheat and basanite. All amendments were mixed with three agricultural topsoils (temperate silty, temperate sandy, tropical sandy) and incubated for 66 days. The δ13C-signal of the respired CO₂ was monitored to determine amendment-induced priming of native SOC. After incubation, a density fractionation was conducted to investigate the potential stabilization of native and biochar-derived SOC as free particulate organic matter (fPOM), occluded POM (oPOM), and mineral-associated organic matter (MAOM).

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