ABSTRACT The application of zinc (Zn) fertiliser to soil has been proposed as a mitigation strategy to decrease plant cadmium (Cd) concentrations. The strategy is untested in New Zealand and it is unclear whether it is effective in soils that are not Zn deficient. We undertook a glasshouse experiment and measured what effect applying Zn had on Cd concentrations in spinach (Spinacia olearacea L.) cultivated in a soil with a high extractable Zn concentration (7.3 mg kg−1) and total Cd concentration of 0.48 mg kg−1. The addition of 5–20 kg Zn ha−1 as zinc sulphate decreased Cd concentrations in spinach leaves after 64 days growth by 19–28% and in roots by up to 42%. In contrast, the addition of Zn increased Zn concentrations in spinach roots and leaves by 55% and 112% respectively. The decrease in Cd concentrations in spinach was likely a result of competition with Zn that restricted Cd uptake into the root. The results indicate there may be potential in using Zn fertiliser to decrease plant Cd concentrations. However, investigation needs to be undertaken to evaluate its effectiveness for soil types with different properties and Zn status, other food crops which may respond differently to spinach and the results confirmed in a field experiment.

中文翻译：

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在锌含量充足的土壤中，施用锌能降低菠菜中的镉浓度吗？

摘要 在土壤中施用锌 (Zn) 肥料已被提议作为降低植物镉 (Cd) 浓度的缓解策略。该策略在新西兰未经测试，目前尚不清楚它在不缺锌的土壤中是否有效。我们进行了温室实验并测量了施用锌对在可提取锌浓度高（7.3 mg kg-1）和总镉浓度为 0.48 mg kg-1 的土壤中栽培的菠菜（Spinacia olearacea L.）中镉浓度的影响. 添加 5-20 kg Zn ha-1 作为硫酸锌可使生长 64 天后菠菜叶中的 Cd 浓度降低 19-28%，根中的 Cd 浓度降低高达 42%。相比之下，添加锌使菠菜根和叶中的锌浓度分别增加了 55% 和 112%。菠菜中 Cd 浓度的降低可能是与 Zn 竞争的结果，限制了根部对 Cd 的吸收。结果表明，使用锌肥可能有降低植物镉浓度的潜力。然而，需要进行调查以评估其对不同性质和锌状态的土壤类型、其他可能对菠菜有不同反应的粮食作物的有效性，并在田间试验中得到证实。