Salinization remains a major issue in soil degradation, for which biochar is a potential solution. In this -analysis, using 660 paired observations from 99 peer-reviewed articles, we evaluated biochar's effect on salt-affected soils and identified the initial soil properties, biochar properties and experimental factors influencing its efficacy. The results showed that the addition of biochar had a significant ameliorating effect on salt-affected soils. The soil electrical conductivity of saturated paste extract (ECe) was significantly reduced by 13.2%, and such effect was significant in severe salinization soil (rather than slight and moderate salinization). Meanwhile, the soil cation exchange capacity was significantly increased by 17.0%. However, the addition of biochar had no significant impact on soil pH. Model selection analyses further indicated that the level of initial salinity and the type of biochar feedstock were the most important factors regulating the response of soil ECe to biochar addition. In summary, while our study highlights the potential of biochar in ameliorating salt-affected soils, particularly in severely salinized soils, it also underscores the need for more comprehensive research in this field. Additional research is necessary to comprehensively address the significant heterogeneity of biochars, including their thorough characterization. In addition, more studies are required to explore the impact of biochar on both salt-tolerant and non-salt-tolerant plants in salt-affected soils.

中文翻译：

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添加生物炭可降低受盐影响的土壤中的盐度，而不影响土壤 pH 值：一项荟萃分析

盐碱化仍然是土壤退化的一个主要问题，生物炭是一个潜在的解决方案。在这项分析中，我们利用来自 99 篇同行评审文章的 660 个配对观察结果，评估了生物炭对受盐影响的土壤的影响，并确定了初始土壤特性、生物炭特性以及影响其功效的实验因素。结果表明，生物炭的添加对盐渍土壤具有显着的改良效果。饱和糊状提取物（ECe）使土壤电导率显着降低13.2%，且这种效果在重度盐化土壤（而不是轻度和中度盐化）中更为显着。同时，土壤阳离子交换能力显着提高17.0%。然而，生物炭的添加对土壤pH值没有显着影响。模型选择分析进一步表明，初始盐度水平和生物炭原料类型是调节土壤ECe对生物炭添加响应的最重要因素。总之，虽然我们的研究强调了生物炭在改善受盐影响的土壤（特别是严重盐化土壤）方面的潜力，但它也强调了在该领域进行更全面研究的必要性。需要进行更多的研究来全面解决生物炭的显着异质性，包括其彻底的表征。此外，还需要更多的研究来探索生物炭对受盐影响的土壤中耐盐和非耐盐植物的影响。