Exploring the Presence of Five Rare Earth Elements in Vineyard Soils on Different Lithologies: Campo de Calatrava, Spain

The aim of the work described here was to understand the pedogeochemical signature of five rare earth elements (REEs; Ce, Nd, La, Y, and Sc) in vineyard soils in Campo de Calatrava (a unique territory with calcareous, volcanic and metamorphic rocks). The mean contents in surface horizons of Ce, Nd, La, Y, and Sc were 65.7, 32.0, 35.5, 18.8, and 13.9 mg.kg(-1), respectively. In subsurface horizons the contents were Ce 62.8, Nd 31.1, La 35.7, Y 17.9, and Sc 14.4 mg.kg(-1). The results show that mean contents of REEs in the area under investigation are in the order Ce > Nd > La > Y > Sc. Ce has a very high range, with a value close to 150 mg.kg(-1). On the other hand, concentrations of Ce, Nd, Y, and Sc are higher in soils on volcanic material than in soils on nonvolcanic material, while only La values are lower in soils on volcanic rocks. The distributional maps of REEs in surface and subsurface horizons suggest that parent material and pedogenesis such as argillization and calcium carbonate accumulation are more important factors than the use of REE-based fertilizers, except in certain exceptional cases (consistent with a possible specific human impact after continuous fertilization).

Automated summary

The study aimed to understand the pedogeochemical signature of five rare earth elements in vineyard soils in Campo de Calatrava. Results showed that the distribution of REEs in soils is related to parent material and soil formation processes, with concentrations of Ce, Nd, Y, and Sc higher in volcanic soils. In some cases, the use of REE-based fertilizers may have a specific human impact on soil chemistry.