The use of biochar as a soil amendment did not affect wine quality in a Müller Thurgau vineyard in South Tyrol (Italy)

Abstract

The use of pyrogenic charcoal (biochar) as a soil amendment in agriculture has ancient origins: it aims to improve soil fertility by changing soil’s chemical and physical properties. Today biochar is further of interest for its long-term carbon fixation effect. Given the high potential of biochar for water and nutrient retention, its use in viticulture may potentially compromise grape and wine quality, since moderate water deficit and limited nitrogen availability are necessary pre-conditions for high quality grape production. The aim of this study was to identify the effects of biochar as a soil amendment on grape and wine quality. The study showed that the addition of biochar pure and biochar enriched with compost in soils did not negatively affect organoleptic properties of the wine. Furthermore, there were no significant differences between volatile organic compounds (VOCs) of wines made from biochar-treated grapes from those of the untreated control. Biochar pure or also moderately enriched with compost as soil amendments did not permanently change nitrogen availability in the soil, nor did they alter the vegetative growth or productivity of the vines. Therefore, the use of biochar in viticulture can be recommended to correct the pH of the soil, increase its water absorption and retention, and for a long-term carbon sequestration, without deleterious effects on growth or productivity, and thus maintaining the quality of the resulting wine.