Enhanced Weathering Using Basalt Rock Powder: Carbon Sequestration, Co-benefits and Risks in a Mesocosm Study With Solanum tuberosum

作者：Arthur Vienne, Sílvia Poblador, Miguel Portillo‐Estrada, Jens Hartmann, Samuel Ijiehon, Peter Wade, Sara Vicca · 发表于：Frontiers in Climate · 年份：2022 · DOI：10.3389/fclim.2022.869456 · 被引用次数：126 · 研究领域：CO2 Sequestration and Geologic Interactions、Clay minerals and soil interactions、Geological and Geochemical Analysis

Enhanced weathering (EW) of silicate rocks can remove CO 2 from the atmosphere, while potentially delivering co-benefits for agriculture (e.g., reduced nitrogen losses, increased yields). However, quantification of inorganic carbon sequestration through EW and potential risks in terms of heavy metal contamination have rarely been assessed. Here, we investigate EW in a mesocosm experiment with Solanum tuberosum growing on alkaline soil. Amendment with 50 t basalt/ha significantly increased alkalinity in soil pore water and in the leachate losses, indicating significant basalt weathering. We did not find a significant change in TIC, which was likely because the duration of the experiment (99 days) was too short for carbonate precipitation to become detectable. A 1D reactive transport model (PHREEQC) predicted 0.77 t CO 2 /ha sequestered over the 99 days of the experiment and 1.83 and 4.48 t CO 2 /ha after 1 and 5 years, respectively. Comparison of experimental and modeled cation pore water Mg concentrations at the onset of this experiment showed a factor three underestimation of Mg concentrations by the model and hence indicates an underestimation of modeled CO 2 sequestration. Moreover, pore water Ca concentrations were underestimated, indicating that the calcite precipitation rate was overestimated by this model. Importantly, basalt amendment did not negatively affect potato growth and yield (which even tended to increase), despite increased Al availability in this alkaline s...