Bioaccumulation of mineral elements in grapevine varieties cultivated in "La Mancha"

The capacity of a plant to take up chemical elements is measured as the ratio of the element concentration in the plant and its concentration in the soil. This ratio is called the bioaccumulation index (BAC). The choice of rootstock and variety can differentially affect nutrient uptake of grapevine (Vitis vinifera L.). Generally, only slight differences can be observed in the accumulation of N, P, and Zn. In contrast, wide variations are found in the absorption of K, Ca, Mg, and Cl. While studies on plant nutrients and major elements have been carried out in vineyards, very few references concern the trace-element concentrations in leaves. In the study described here, five varieties (Airen, Cencibel, Garnacha, Cabernet Sauvignon, and Chardonnay) grown on a Calcisol Petric or Typic Calcixerept (typical of La Mancha) were compared in terms of leaf trace-element concentrations. A total of three samples (20 healthy and completely developed leaves from the middle part of the shoot) were collected from three different plants of the same variety. Leaves were dried, milled, and x-ray fluorescence analysis was performed. It was found that the variety of grapevine influences the uptake of four of the major elements: Al (low in Garnacha, [0.4 +/- 0.2] gkg(-1)), Ca (high in Cencibel, [32.6 +/- 8.1] gkg(-1)), P (low in Airen, [0.9 +/- 0.4] gkg(-1)) and K, which showed significant differences in almost all of the varieties (from [4.7 +/- 1.8] gkg(-1) in Cencibel to [8.0 +/- 10.1] gkg(-1) in Chardonnay). No statistically significant varietal differences were found for trace elements. The only exception was La, which was present at higher levels in the variety Cencibel ([7.5 +/- 0.3] mgkg(-1)). This finding allows to assess the geochemical fingerprinting of calcareous soils regardless of the grapevine variety studied.