Accumulation of rare earth elements in maize plants (Zea mays L.) after application of mixtures of rare earth elements and lanthanum
Accumulation of rare earth elements in maize plants (Zea mays L.) after application of mixtures of rare earth elements and lanthanum
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DOI：
10.1023/a:1024715523670
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发表时间：
2003-05-01
期刊：
影响因子：
4.9
通讯作者：
Witkamp, GJ
中科院分区：
文献类型：
--
作者：
Xu, XK;Zhu, WZ;Witkamp, GJ
稀土元素在中国被广泛应用于提高作物产量，个别稀土元素在本土植物中的分布模式已被广泛报道。但是，我们对施用稀土元素后，个别稀土元素在农作物中积累的剂量依赖性的认识仍然有限。采用盆栽试验研究了镧及混合稀土对玉米植株中单个稀土元素积累的影响。将所有植物样品分为植物顶部和根部。在土壤中添加稀土元素和镧的混合物时，发现单个稀土元素在根和植物顶部中具有显著的剂量依赖性积累。稀土元素混合物在> 10 mg kg（-1）土壤中施用，可显著增加根系中轻稀土元素的含量，在50 mg kg（-1）土壤中施用，可显著增加植株顶端中轻稀土元素的含量。当稀土元素的混合物被镧单独取代时，在高于10 mg La kg（-1）土壤的剂量下，根部和植株顶部的La含量显著增加。玉米植株中La/Ce含量比值随稀土施用量的增加而增加。在最高剂量（50 mg kg（-1）土壤）下，与稀土元素的混合物相比，单独用镧处理后，吸收的镧从根部向植株顶部的运输可能大大减少。增加稀土元素的施用剂量，在根和植株顶端均出现Gd正、Ce负的异常，且在植株顶端的异常比根明显。结果表明，玉米中Gd、Ce的异常可作为稀土元素农业应用安全性评价的重要参数。
Rare earth elements are applied in China to improve crop production, and the distribution patterns of individual rare earth elements in native plants have widely been reported. But our knowledge is still limited about the dose-dependent accumulation of individual rare earth elements in agricultural crops after application of rare earth elements. Effects of lanthanum and mixtures of rare earth elements were studied in pot experiments on the accumulation of individual rare earth elements in maize plants. All plant samples were divided into plant tops and roots. On addition of mixtures of rare earth elements and lanthanum to the soil, a significant dose-dependent accumulation of individual rare earth element(s) was found in the roots and in the plant tops. Application of mixtures of rare earth elements at > 10 mg kg(-1) soil, resulted in a significant increase in contents of light rare earth elements in the roots, and at a dose of 50 mg kg(-1) soil, a similar phenomenon was found in the plant tops. When mixtures of rare earth elements were replaced by lanthanum alone, at a dose higher than 10 mg La kg(-1) soil, a significant increase in La content occurred in the roots and in the plant tops. The content ratio of La to Ce in maize plants appeared to increase as the application doses of rare earth element( s) increased. At a highest dose (50 mg kg(-1) soil), the transport of the absorbed La from the roots to the plant tops might be substantially reduced after treatment with lanthanum alone, compared with mixtures of rare earth elements. Increasing the application doses of rare earth element(s) appeared to cause a positive Gd and negative Ce anomaly in the roots and in the plant tops, and the anomaly was more obvious in the plant tops than in the roots. The results indicated that the Gd and Ce anomaly in corns might be considered as important parameters for the safety assessment of agricultural application of rare earth elements.