V. Valcheva, K. Trendafilov, S. Todorova
Abstract. The influence of mineral fertilization with nitrogen, phosphorus and potassium on the indicators of harmful soil acidity and on the composition of plant biomass from vine varieties Sauvignon Blanc, Chardonnay, Cabernet Sauvignon and Merlot in fertility, planted on Chromic luvisol was evaluated. It was found that long-term balanced mineral fertilization has a pronounced effect on neutralization of the exchangeable H+. In relatively weak buffer capacity of soil sorption complex in unsaturated soils, buffering capacity associated with the transformation of phosphates and activity of K+ from fertilizers causes a decrease in equilibrium concentrations of exchangeable hydrogen. The influence of balanced fertilization of vines with nitrogen, phosphorus and potassium on the composition of air-dried foliage and fresh grapes in commercial ripeness was also studied. Mineral fertilization with primary nutrients causes an increase in nitrogen content in both leaves and grapes in all studied varieties. It does not lead to changes in content of phosphorus in the foliage and grapes, while potassium content increases only in leaves.