This study aimed at understanding the uptake pathway of combined copper, zinc, and molybdenum applied to soybean (Glycine max (L.) Merrill) and maize (Zea mays (L.) seeds and their effect on seedling development. Two doses—2 and 4 mL kg⁻¹ seeds—of a mixed copper, zinc, and molybdenum formulation were applied on both seed species, and process efficiency, i.e., how much of the applied solutions were transferred to the seeds, was determined. The spatial distribution of these nutrients was examined through microprobe X-ray fluorescence spectroscopy, and the effects on seed germination and seedling’s root and shoot development were recorded. Besides, the fraction of applied nutrients transferred from the seeds up to the seedlings tissues and the efficiency of the coating process were quantified. The results showed that seed treatments presented an overall efficiency of 70%. Most of the nutrients applied remained attached to the seed surface, i.e., seed coat or pericarp tissues in both species, being transferred to the soil afterwards. Only a tiny fraction of zinc, copper, and molybdenum was found in root and shoot tissues germinated from the coated seeds. The treatments did not impair seed germination or affected the content of the other mineral elements in the root and shoot tissues, although it had promoted a slight increase on maize’s root tissue length and dry mass. These results bring to light that the current seed treatment transfers part of the nutrients directly to the early developing seedling, while the remaining is precisely deposited in the soil volume where the root system will develop.

本研究旨在了解大豆（Glycine max (L.) Merrill）和玉米（Zea mays (L.) 种子对铜、锌和钼的复合吸收途径及其对幼苗发育的影响。两个剂量——2 和将 4 mL kg ^-1种子——铜、锌和钼的混合制剂应用于两种种子种类和工艺效率，即.，确定有多少应用溶液被转移到种子上。通过微探针X射线荧光光谱检测这些养分的空间分布，并记录对种子萌发和幼苗根和芽发育的影响。此外，应用的营养物质从种子转移到幼苗组织的比例和包衣过程的效率被量化。结果表明，种子处理的总体效率为 70%。施用的大部分养分仍附着在种子表面，即，两种物种的种皮或果皮组织，然后转移到土壤中。在从包衣种子发芽的根和芽组织中只发现了一小部分锌、铜和钼。尽管处理促进了玉米根组织长度和干重的轻微增加，但这些处理并未损害种子萌发或影响根和芽组织中其他矿质元素的含量。这些结果表明，当前的种子处理将部分养分直接转移到早期发育的幼苗中，而其余的则精确地沉积在根系将发育的土壤体积中。