A 35-day microcosmic experiment was conducted with lettuce (Lactuca sativa L.) and two metalaxyl (MET) enantiomers (R-MET and S-MET) to understand the roles of biochar in the enantioselective fate of chiral pesticides in soil-plant ecosystems. Wood waste-derived biochar (WBC) amendment effectively decreased the shoot concentrations of R-MET/S-MET and their metabolites R-MET/S-MET acid by 57.7–86.3% and 13.3–32.5%, respectively. The reduced uptake was mainly attributed to the decreased bioavailability of R-MET and S-MET. A lower fraction of R-MET was accumulated by the lettuce in the WBC-amended soils relative to the control, suggesting a decrease in the enantioselective uptake of the chiral pesticide MET in the presence of biochar. Regardless of the WBC amendment, no enantiomerization of MET or MET acid occurred. The application of WBC stimulated soil bacterial diversity, shifted the bacterial community, and enhanced the abundance of pesticide degrading bacteria (e.g., Luteimonas, Methylophilus, and Hydrogenophaga), which were responsible for the enantioselective degradation of MET in the soil. This work expands our understanding of the enantioselective fate of chiral pesticides in the biochar-amended soil ecosystems. These findings can be used to develop biochar-based technologies to remediate soils contaminated with these chiral pesticides to ensure food safety.

使用生菜 ( Lactuca sativa L.) 和两种甲霜灵 (MET) 对映体（ R -MET 和S -MET）进行了为期 35 天的微观实验，以了解生物炭在土壤-植物生态系统中手性农药对映选择性命运中的作用。木材废料衍生的生物炭（WBC）改良剂有效地将R -MET / S -MET 及其代谢物R -MET / S -MET 酸的地上部浓度分别降低了 57.7-86.3% 和 13.3-32.5%。摄取减少主要归因于R -MET和S -MET的生物利用度降低。与对照相比，WBC 修正土壤中的生菜积累了较低比例的R -MET，表明在生物炭存在的情况下，手性农药 MET 的对映选择性吸收减少。无论 WBC 修正如何，MET 或 MET 酸均未发生对映异构化。 WBC的应用刺激了土壤细菌多样性，改变了细菌群落，并增加了农药降解菌（例如黄体单胞菌属、嗜甲基菌属和氢噬菌属）的丰度，这些细菌负责土壤中MET的对映选择性降解。这项工作扩展了我们对生物炭改良土壤生态系统中手性农药的对映选择性命运的理解。这些发现可用于开发基于生物炭的技术来修复被这些手性农药污染的土壤，以确保食品安全。