Biochar application to soil has the potential to affect soil and vegetation properties that are key for the processes of runoff and soil erosion. However, both field and pot experiments show a vast range of effects, from strong reductions to strong increases in runoff and/or soil erosion. Therefore, this study aimed to quantify and interpret the impacts of biochar on runoff and soil erosion through the first systematic meta-analysis on this topic. The developed dataset consists of 184 pairwise observations for runoff soil erosion from 30 independent studies but 8 of which just focused on soil erosion. Overall, biochar application to soil significantly reduced runoff by 25 % and erosion by 16 %. Mitigation of soil erosion in the tropics was approximately three times stronger (30 %) than at temperate latitudes (9 %); erosion reduction in the subtropical zone was 14 %, but not significantly different from either the tropical or temperate zones. Fewer reported field observations for runoff resulted in larger confidence intervals and only the temperate latitudes showed a significant effect (i.e. a 28 % reduction). At topsoil gravimetric biochar concentrations between 0.6 % and 2.5 %, significant reductions occurred in soil erosion, with no effect at lower and higher concentrations. Biochar experiments that included a vegetation cover reduced soil erosion more than twice as much as bare soil experiments, i.e. 27 % vs 12 %, respectively. This suggests that soil infiltration, canopy interception, and soil cohesion mechanisms may have synergistic effects. Soil amended with biochar pyrolyzed at >500 °C was associated with roughly double the erosion reduction than soil amended with biochar produced at 300–500 °C, which potentially could be related to the enhancement of hydrophobicity in the latter case. Our results demonstrate substantial potential for biochar to improve ecosystem services that are affected by increased infiltration and reduced erosion, while mechanistic understanding needs to be improved.

将生物炭应用于土壤有可能影响土壤和植被特性，这些特性是径流和土壤侵蚀过程的关键。然而，田间和盆栽试验都显示出范围广泛的影响，从径流和/或土壤侵蚀的强烈减少到强烈增加。因此，本研究旨在通过对该主题的首次系统荟萃分析来量化和解释生物炭对径流和土壤侵蚀的影响。开发的数据集包括来自 30 项独立研究的 184 项径流土壤侵蚀成对观测，但其中 8 项仅关注土壤侵蚀。总体而言，将生物炭施用于土壤显着减少了 25% 的径流和 16% 的侵蚀。热带地区土壤侵蚀的缓解作用 (30%) 大约是温带地区 (9%) 的三倍；亚热带地区的侵蚀减少了 14%，但与热带或温带地区没有显着差异。较少报告的径流实地观测导致较大的置信区间，并且只有温带纬度显示出显着影响（即减少 28%）。当表土重量生物炭浓度在 0.6% 和 2.5% 之间时，土壤侵蚀显着减少，而在较低和较高浓度下没有影响。包括植被覆盖的生物炭实验减少土壤侵蚀的程度是裸土实验的两倍多，即分别为 27% 和 12%。这表明土壤入渗、冠层截留和土壤凝聚力机制可能具有协同效应。用热解的生物炭改良的土壤 > 与在 300-500 °C 下生产的生物炭改良的土壤相比，500 °C 的侵蚀减少大约两倍，这可能与后一种情况下疏水性的增强有关。我们的研究结果表明，生物炭在改善受渗透增加和侵蚀减少影响的生态系统服务方面具有巨大潜力，同时需要提高对机理的理解。