Multiyear Soil-Fruit Transfer Dynamics of Macro- and Trace Elements in Raspberry (Rubus idaeus L.) Under Field...

Understanding the soil-plant transfer of both essential and non-essential elements is crucial for evaluating the crop nutritional quality, environmental interactions, and food safety. This study delivered a multiyear and multielement assessment under field conditions of the element uptake, translocation, and accumulation in raspberry (Rubus idaeus L.), based on data collected over two growing seasons (2024-2025) in two contrasting Romanian agroecosystems. Two commercial cultivars (Opal and Delniwa) were investigated under fertilized and unfertilized conditions. The concentrations of essential macroelements such as Ca, Mg, Na, and K, as well as trace elements (Li and Sr), were determined in soils and fruits using ICP-OES and AAS. The soil-fruit transfer was quantified through the transfer factor, assisted by a robust statistical framework which integrated spatial-temporal variability and non-parametric analysis. The results highlighted two contrasting accumulation regimes. The essential macroelements revealed a dynamic uptake pattern driven by the physiological demand, soil availability, and fertilization. K exhibited the highest transfer capacity, while Ca had a restricted translocation to the fruits, due to the intrinsic transport limitations. On the other hand, Li and Sr revealed a constrained accumulation, characterized by low concentrations, weak responsiveness to fertilization, and a strong dependence on the soil geochemical background and interannual dilution processes. The spatial variability between the cultivation sites and year-to-year changes in the dilution intensity was evidenced as the dominant driver of the transfer efficiency, while the varietal differences had a secondary but detectable role, mainly for the Ca-Sr discrimination. Overall, the results evidenced that the multielement accumulation in the raspberries was governed by the interplay between the soil geochemistry, physiological transport constraints, and environmental variability. Furthermore, the research provided a field-based, multiyear evidence supporting improved soil management, cultivar selection, as well as the strategies that may increase the fruit nutritional quality while minimizing the trace element risks.