Using isotopes to trace freshly applied cadmium through mineral phosphorus fertilization in soil-fertilizer-plant systems.
Using isotopes to trace freshly applied cadmium through mineral phosphorus fertilization in soil-fertilizer-plant systems.
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DOI：
10.1016/j.scitotenv.2018.08.127
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发表时间：
2019-01
期刊：
影响因子：
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通讯作者：
M. Wiggenhauser;M. Bigalke;M. Imseng;A. Keller;M. Rehkämper;W. Wilcke;E. Frossard
中科院分区：
文献类型：
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作者：
M. Wiggenhauser;M. Bigalke;M. Imseng;A. Keller;M. Rehkämper;W. Wilcke;E. Frossard
施用矿物磷(P)肥可导致土壤中Cd的积累，并可增加可食用作物部位的Cd浓度。为了确定新施Cd的去向，利用放射性同位素109Cd标记的矿物磷肥和Cd稳定同位素组成的自然差异(δ114/110Cd)，在3个土壤-肥料-小麦系统中进行了Cd来源示踪试验。稳定同位素溯源高估了植物体内Cd的比例，因为来源的同位素比值与土壤的不完全不同。尽管对照和处理之间无法区分可提取的Cd库，但增施磷肥导致土壤和小麦之间的表观同位素分馏更负。总体而言，放射性同位素方法提供了更可靠的结果，揭示了地上部6.5%至15%的Cd来自化肥。从引入的Cd中，最高可达2.2%到达小麦地上部，而97.8%留在根和土壤中。肥料Cd的低回收率表明，过去几十年连续施用磷肥可能会导致土壤中残留Cd库的积累。
Applications of mineral phosphorus (P) fertilizer can lead to cadmium (Cd) accumulation in soils and can increase Cd concentrations in edible crop parts. To determine the fate of freshly applied Cd, a Cd source tracing experiment was conducted in three soil-fertilizer-wheat systems by using a mineral P fertilizer labeled with the radio isotope109Cd and by exploiting natural differences in Cd stable isotope compositions (δ114/110Cd). Source tracing with stable isotopes overestimated the proportion of Cd in plants derived from the P fertilizer, because the isotope ratios of the sources were not sufficiently distinct from those of the soils. Despite indistinguishable extractable Cd pools between control and treatments, the addition of P fertilizer resulted in a more negative apparent isotope fractionation between soil and wheat. Overall, the radio isotope approach provided more robust results and revealed that 6.5 to 15% of the Cd in the shoot derived from the fertilizer. From the introduced Cd, a maximum of 2.2% reached the wheat shoots, whilst 97.8% remained in the roots and soils. The low recoveries of the fertilizer derived Cd suggest that continuous P fertilizer application in the past decades can lead to a build-up of a residual Cd pool in soils.