The Effect of a Leaf Fertilization Method Using Humic Acids on the Minerality and Chemical Composition of Sauvignon Blanc Wine from the Slovak Wine Region

The objective of this study was to analyze the minerals transferred to Sauvignon blanc must and wine as an effect of foliar fertilizer application. The mineral composition was determined via atomic absorption spectroscopy. Experimental leaf and berry samples were examined during the phenological grapevine growth phases. A foliar fertilizer mixture (0.5 L/hL) with humic acids (8.51%) and B (0.031 kg) was applied. It was observed that the application of humic acids and boron significantly influenced the quality of Sauvignon blanc wine samples. During the blooming period, there was a statistically significant increase (p < 0.05) in P, K, and B in the experimental group. The results showed that using HAs and B in foliar fertilizer significantly (p < 0.05) increased the concentration of minerals in the experimental group. However, P and Fe content in the leaves decreased after veraison. After processing the berries in the vinification process, the levels of B in the must (0.71 ± 0.06 mg/kg) and, subsequently, in the wine (0.61 ± 0.06 mg/kg) were significantly (p < 0.05) higher in the experimental group. Data showed that the foliar fertilizer significantly increased the concentration of N (176.24 ± 0.02 mg/L) in the experimental must. These changes were also observed in wine samples. In wine, a statistically significant decrease in Ca (82.86 ± 0.29 mg/kg) was observed.