Abstract

Environmental contamination by toxic trace elements is a global issue faced by soil-plant-human systems. Biochar has gained substantial attention as a soil amendment to reduce toxic trace element impacts on plant and human health due to biochar’s capacity to influence trace element biogeochemistry. This review focuses on the key roles of biochar with respect to trace element interactions, mobility and phytoavailability in soil-plant systems. In addition to direct interactions, various biochar types can impact soil physicochemical properties and subsequently trace element biogeochemical behavior. A critical literature review revealed increasing and/or decreasing trends with respect to biochar-induced variation in soil physicochemical characteristics and soil-plant trace element transfer. Data analysis revealed that biochar-mediated an overall decrease in the phyto-uptake of As, Cd, Cu, Ni, Pb, and Zn by 48%, 40%, 38%, 44%, 28%, and 22%, respectively. This article also discusses the possible biochar-mediated alleviations of human health hazards (41% less cancer risk) due to consuming trace elements-contaminated foods. Likewise, for the first time, the effect of soil biochar application on plant physiological and morphological attributes, as well as activation of tolerance mechanisms (enzymatic and non-enzymatic) is critically discussed.

• Highlights

• Literature review revealed biochar applications increased soil trace element sorption and decreased phyto-uptake.

• Plant uptake of trace element depends on soil and biochar properties as well as trace element and plant type.

• Biochar-mediated trace element phytoavailability reductions cause lower toxicity in plant-human systems.

• Biochar alters plant detoxification and tolerance mechanisms directly or indirectly.

摘要

有毒微量元素对环境的污染是土壤-植物-人类系统面临的全球性问题。由于生物炭具有影响微量元素生物地球化学的能力，生物炭作为一种土壤改良剂以减少有毒微量元素对植物和人类健康的影响而受到广泛关注。本综述侧重于生物炭在土壤-植物系统中在微量元素相互作用、流动性和植物有效性方面的关键作用。除了直接相互作用外，各种生物炭类型还可以影响土壤的物理化学性质，进而影响微量元素的生物地球化学行为。一篇重要的文献综述揭示了生物炭引起的土壤理化特性变化和土壤-植物微量元素转移的增加和/或减少趋势。数据分析显示，生物炭介导的植物对 As、Cd、Cu、Ni、Pb 和 Zn 的吸收分别下降了 48%、40%、38%、44%、28% 和 22%。本文还讨论了由于食用受微量元素污染的食物，生物炭可能会减轻人类健康危害（癌症风险降低 41%）。同样，首次批判性地讨论了土壤生物炭应用对植物生理和形态属性的影响，以及耐受机制（酶促和非酶促）的激活。

• 强调

• 文献回顾表明，生物炭的应用增加了土壤微量元素的吸附，减少了植物的吸收。

• 植物对微量元素的吸收取决于土壤和生物炭特性以及微量元素和植物类型。

• 生物炭介导的微量元素植物有效性降低导致植物-人类系统毒性降低。

• Biochar 直接或间接改变植物解毒和耐受机制。