Copper (Cu) mining operations have a global footprint and have led to contamination of soils and Cu toxicity to plants. Understanding the controls of plant Cu uptake, including competition with other metals, such as zinc (Zn), is essential for improving plant growth in Cu-contaminated soils. The objective of this study was to evaluate the capacity of Zn to alleviate the toxicity of Cu in crops grown in Cu-contaminated soils. Lettuce was grown in 27 soils with ranges of total Cu and Zn concentrations of 82–1295 mg Cu kg⁻¹ and 86–345 mg Zn kg⁻¹ for a period of 21 days. Oat was grown in 21 soils with the same total Cu and Zn concentration ranges for a period of 62 days. Regression analyses were used to evaluate the impact of total soil Zn on plant growth in the Cu-contaminated soils. We show for the first time that Zn alleviates Cu toxicity in lettuce and oat grown in soils. Specifically, we observed a negative (toxicity) effect of total soil Cu and a positive (protective) effect of total soil Zn on shoot growth response for lettuce and oat. The effective concentration 50% (EC₅₀) of Cu/Zn mass ratio was 7.0 ± 1.8 for lettuce shoot length and 5.9 ± 1.0 for oat shoot weight. These results indicate that the previously demonstrated efficacy of Zn in mitigating Cu phytotoxicity in hydroponic systems can extend to more complex soil systems. Further research should be done to evaluate specific Zn amendments for restoring vegetative growth in Cu-contaminated soils.

铜（Cu）采矿业务遍及全球，并导致土壤污染和Cu对植物的毒性。了解植物对铜吸收的控制，包括与其他金属（例如锌（Zn））的竞争，对于改善铜污染土壤中的植物生长至关重要。这项研究的目的是评估锌缓解铜污染土壤中生长的农作物中铜的能力。生菜生长在27种土壤中，铜和锌的总浓度范围为82-1295 mg Cu kg ^-1和86-345 mg Zn kg ^-1为期21天。燕麦在相同的铜和锌总浓度范围内的21种土壤中生长62天。回归分析用于评估土壤总锌对铜污染土壤中植物生长的影响。我们首次表明锌减轻了土壤中生菜和燕麦中铜的毒性。具体而言，我们观察到土壤中总铜的负（毒性）作用和土壤中总锌的正（保护）作用对生菜和燕麦的苗期生长响应。有效浓度50％（EC ₅₀）的Cu / Zn质量比对于生菜芽长度为7.0±1.8，对于燕麦芽重量为5.9±1.0。这些结果表明，先前证明的Zn减轻水耕系统中Cu的植物毒性的功效可以扩展到更复杂的土壤系统。应该做进一步的研究来评估特定的锌改良剂，以恢复铜污染土壤中的营养生长。