Biobased Sustainability Engineering (SUSTAIN), Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium.
GFZ German Research Centre for Geosciences, Potsdam, Germany.
Glob Chang Biol. 2024 Sep;30(9):e17511. doi: 10.1111/gcb.17511.
Climate change is one of the most urgent environmental challenges that humanity faces. In addition to the reduction of greenhouse gas emissions, safe and robust carbon dioxide removal (CDR) technologies that capture atmospheric CO and ensure long-term sequestration are required. Among CDR technologies, enhanced silicate weathering (ESW) has been suggested as a promising option. While ESW has been demonstrated to depend strongly on pH, water, and temperature, recent studies suggest that biota may accelerate mineral weathering rates. Bacillus subtilis is a plant growth-promoting rhizobacterium that can facilitate weathering to obtain mineral nutrients. It is a promising agricultural biofertilizer, as it helps plants acquire nutrients and protects them from environmental stresses. Given that croplands are optimal implementation fields for ESW, any synergy between ESW and B. subtilis can hold great potential for further practice. B. subtilis was reported to enhance weathering under laboratory conditions, but there is a lack of data for soil applications. In a soil-mesocosm experiment, we examined the effect of B. subtilis on basalt weathering. B. subtilis-basalt interaction stimulated basalt weathering and increased soil extractable Fe. The combined application displayed higher CDR potential compared to basalt-only application (3.7 vs. 2.3 tons CO ha) taking solid and liquid cation pools into account. However, the cumulative CO efflux decreased by approximately 2 tons CO ha with basalt-only treatment, while the combined application did not affect the CO efflux. We found limited mobilization of cations to the liquid phase as most were retained in the soil. Additionally, we found substantial mobilization of basalt-originated Mg, Fe, and Al to oxide- and organic-bound soil fractions. We, therefore, conclude that basalt addition showed relatively low inorganic CDR potential but a high capacity for SOM stabilization. The outcomes indicated the importance of weathering rate-GHG emission integration and the high potential of SOM stabilization in ESW studies.
气候变化是人类面临的最紧迫的环境挑战之一。除了减少温室气体排放外，还需要安全且强大的二氧化碳去除（CDR）技术，这些技术可以捕获大气中的 CO 并确保长期封存。在 CDR 技术中，增强的硅酸盐风化（ESW）已被认为是一种很有前途的选择。尽管 ESW 已被证明强烈依赖于 pH 值、水和温度，但最近的研究表明，生物群可能会加速矿物风化速率。枯草芽孢杆菌是一种促进植物生长的根际细菌，可以促进风化以获取矿物养分。它是一种很有前途的农业生物肥料，因为它可以帮助植物获取养分并保护它们免受环境压力的影响。鉴于农田是 ESW 的最佳实施领域，因此 ESW 与枯草芽孢杆菌之间的任何协同作用都可能具有很大的实践潜力。枯草芽孢杆菌已被报道在实验室条件下增强风化作用，但缺乏土壤应用的数据。在土壤中观实验中，我们研究了枯草芽孢杆菌对玄武岩风化的影响。枯草芽孢杆菌-玄武岩相互作用刺激了玄武岩风化并增加了土壤可提取的 Fe。与仅使用玄武岩相比，联合应用的 CDR 潜力更高（考虑固液阳离子池后为 3.7 吨 CO ha 与 2.3 吨 CO ha）。然而，仅用玄武岩处理时，累计 CO 通量减少了约 2 吨 CO ha，而联合应用并未影响 CO 通量。我们发现，由于大部分阳离子被保留在土壤中，只有有限的阳离子向液相迁移。此外，我们发现大量的玄武岩起源的 Mg、Fe 和 Al 迁移到氧化物和有机结合的土壤部分。因此，我们得出结论，玄武岩的添加显示出相对较低的无机 CDR 潜力，但具有很高的 SOM 稳定能力。研究结果表明，风化速率与温室气体排放的整合以及 SOM 在 ESW 研究中的稳定潜力非常重要。
