ABS 2027

Abstract: Rare earth elements (REEs), including 15 lanthanides and yttrium, share similar physiochemical properties and typically occur together in the environment. Naturally, their soil abundance is highly source-specific, i.e., ΣREEs was higher in soils from granite, sandstone and shale, and mafic rock than those from andesite and ultramafic rock. Additionally, soils from felsic and intermediate rocks were light REEs (LREEs, Z = 57–64) enriched, while those from mafic and ultramafic rocks contained higher heavy REEs (HREEs, Z = 39, and 65–71) levels. Moreover, the gradually decreased ionic radius with the increasing atomic weight of REEs (i.e., lanthanide contraction) resulted in the preferential sequestration of iron oxides for HREEs, leading to their co-translocation and accumulation of HREEs during the illuviation, as quantified by the lower GdN/YbN in subsurface soils. Similarly, carbonates tended to associate HREEs, whilst calcium competed the binding sites of LREEs due to their similar ionic potentials, causing the decrease of GdN/YbN in carbonate nodules compared to the bulk soils during calcification. On the other hand, tea trees cultivated in eastern Taiwan (Philippine Sea Plate) owned higher REEs concentrations and a figure enriched with LREEs compared to those grown in western Taiwan (Eurasian Plate). Also, rice grown on soils derived from slate, sandstone, and shale could be differentiated by comparing their Ce, Gd, and Eu anomaly values. In other words, the origin-specific abundance and pedogenesis-driven fractionation of soil REEs provide the scientific foundation for applying REEs as pedogenic tracer and in traceability system for agricultural products.

Biography: Prof. Zeng-Yei Hseu is a Distinguished Professor in the Department of Agricultural Chemistry at National Taiwan University. His areas of expertise include pedology and soil health assessment with research focusing on biogeochemistry of trace and rare earth elements in soil-plant systems and soil carbon sequestration. He previously served as Chair of the Department of Agricultural Chemistry at National Taiwan University and has also served as a Visiting Professor at Kyoto University in Japan. He was President of the East and Southeast Asian Federation of Soil Science Societies. Professor Hseu has received numerous academic honors, including the 2024 Outstanding Research Award from Taiwan’s National Science and Technology Council and the 2026 Future Technology Award. To date, Professor Hseu has published approximately 150 papers in international peer-reviewed journals. He currently serves as an Associate Editor of CATENA and as an Editorial Board Member of Environmental Pollution, Geoderma Regional, and Soil Science and Plant Nutrition. For more information, please visit: https://webpageprodvm.ntu.edu.tw/SSR