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 isotope ¹⁰⁹Cd and by exploiting natural differences in Cd stable isotope compositions (δ^114/110Cd). 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.

施用无机磷（P）肥料会导致土壤中镉（Cd）的积累，并会增加可食用作物部分中Cd的浓度。为了确定命运的新施加镉，Cd的溯源实验在三个土壤的肥料-小麦系统中进行，通过使用标记有放射性同位素矿物磷肥¹⁰⁹ Cd和通过利用在镉稳定同位素组合物的天然差异（δ ^{114 / 110}光盘）。具有稳定同位素的源示踪法高估了源自磷肥的植物中Cd的比例，因为源的同位素比与土壤的同位素比没有足够的区别。尽管对照和处理之间的可提取Cd池难以区分，但添加P肥料导致土壤和小麦之间的表观同位素分馏更为不利。总体而言，放射性同位素方法提供了更可靠的结果，并揭示了枝条中Cd的6.5％至15％来自化肥。从导入的镉中，最多有2.2％到达麦芽，而根​​和土壤中仍然有97.8％。化肥衍生的镉的回收率低，这表明在过去的几十年中连续施用磷肥会导致土壤中残留镉的积累。