Excessive cadmium (Cd) in soils is a serious threat to food safety. Combinations of fungal endophytes and biochar have been shown to restrict Cd accumulation in crop plants, but the interactions of Paecilomyces variotii extracts (ZNC) and biochar on the remediation of alkaline Cd-contaminated soil remain unclear. This work aimed to study the Cd immobilization ability by amendment with ZNC and biochar via column experiments. The results indicated that ZNC alleviated the inhibition of Cd on photosynthesis of maize, thus supporting Cd resistance by growth promotion. Biochar promoted the conversion of exchangeable Cd into a less-available form, which reduced the content of DTPA-extractable Cd by 4.93 ~ 21.28% and − 0.83 ~ 19.51% in the 0–10- and 10–20-cm soil layers, respectively. The combination of biochar and ZNC substantially reduced Cd concentrations in maize plants, with more significantly lower grain Cd concentrations in higher biochar dosage treatments. These findings indicate that the combination of ZNC and biochar has significant potential to promote plant growth by altering Cd bioavailability and Cd tolerance in alkaline Cd-contaminated soil.

土壤中过量的镉 (Cd) 对食品安全构成严重威胁。真菌内生菌和生物炭的组合已被证明可以限制作物中 Cd 的积累，但拟青霉的相互作用提取物（ZNC）和生物炭对碱性镉污染土壤的修复仍不清楚。本工作旨在通过柱实验研究ZNC和生物炭修饰后的Cd固定能力。结果表明，ZNC减轻了Cd对玉米光合作用的抑制，从而通过促进生长来支持Cd抗性。生物炭促进交换性 Cd 转化为低可用形式，使 0-10- 和 10-20-cm 土层中 DTPA 可萃取 Cd 的含量分别降低 4.93 ~ 21.28% 和 - 0.83 ~ 19.51% . 生物炭和 ZNC 的组合显着降低了玉米植株中的 Cd 浓度，在较高的生物炭剂量处理中谷物 Cd 浓度更显着降低。