Elemental Composition of Ilex paraguariensis Grown in the Brazil–Paraguay Border Region

The mineral composition of Ilex paraguariensis is strongly shaped by the physicochemical characteristics and natural fertility of the soils in which it is cultivated. This study evaluated macro- and microelement concentrations in fresh leaves from fourteen rural properties in Mato Grosso do Sul, Brazil, and examined how soil texture, pH, organic matter content, cation exchange capacity (CEC), and aluminum saturation influence nutrient availability and foliar accumulation. Soil, leaf, and environmental data were analyzed using ANOVA, intraclass correlation coefficients, Bayes factors, and principal component analysis (PCA). Sandy and dystrophic soils with low CEC and reduced organic matter showed greater variability in micronutrient retention and favored leaching, resulting in higher fluctuations in foliar Cu, Zn, and Mn. In contrast, clayey eutrophic soils with high CEC and higher organic matter promoted greater nutrient stability and more homogeneous foliar concentrations of K, Mg, and P. PCA confirmed that differences in soil geochemistry, particularly in Se, Cr, Mn, and Zn availability, were reflected in leaf composition. Chromium remained low in leaves despite elevated soil levels, indicating restricted uptake and translocation. Overall, the results demonstrate that edaphic conditions govern the nutritional profile of I. paraguariensis, emphasizing the need for region-specific soil management to maintain leaf quality in emerging cultivation areas.