Effects of distillery vinasses on vineyard yield and quality in the D.O.C “Oltrepò Pavese Pinot Nero” – Lombardy, Italy

In a fifteen year old vineyard of Pinot Noir at a density of 5000 vines per hectares, located in the DOC zone Oltrepò Pavese, the influence of growing doses of distillery vinasses on vegetative growth, leaf mineral levels, grape yield and quality was tested in a four year period. Doses of vinasses were computed to apply 0 (test), 50, 100, 150 kg N ha⁺¹. Vinasses doses were factorially combined with three levels of urea (0, 50 and 100 kg N ha⁺¹). In plots without vinasses supply, ureic nitrogen reduced the number of blind buds and increased the potential and actual bud fertility. The application of vinasses nitrogen had a similar result, even if ureic and vinasses nitrogen had no additive effects. The most profitable grape yield was obtained by application of 50 kg ha⁺¹ of nitrogen either in urea or in vinasses form. Highest vinasses supply improved the ripening levels of grapes increasing sugars and reducing acidity of juice. Results clearly show the possibility to use vinasses for proper vineyard fertilisation.