In his keynote speech during Enoforum Web 2020, Professor Stefano Poni, from the Univ. Cattolica del Sacro Cuore, presents the results obtained in a medium-term study aimed at verifying the effectiveness of variable rate nitrogen fertilization.
The studies were conducted on small cv Barbera vineyards grown in the Colli Piacentini which were first assessed for intra-vineyard variability. The resulting vigor map was used as a prescription to set up variable rate N applications (VRA) using urea as an N fertilizer in experiment 1 and the slow-release form Multicote Agri in the second experiment. The VRA strategy was compared with standard management, proving a fixed amount of fertilizer regardless of vigor level and a control treatment, providing no N.
In both studies, despite the small surface, large variability in vine vigor did exist with consequent differences in canopy development, yield and grape composition. In term of VRT effectiveness, it was ascertained that while urea had, on a 4 year basis, a quite mild effectiveness at increasing vigor in the weak plots, Multicote Agri was much more effective since a close linear relationship was established between the amount of delivered Multicote Agri and leaf area and yield per vine.
The obtained results point out that effectiveness of a variable rate approach is also bound to the form of N used for fertilization.
Prof. Stefano Poni is a full professor of Viticulture and Chair of the Department of Sustainable Crop Production at the Università Cattolica del Sacro Cuore of Piacenza (Italy). Awarded of the “Perdisa” prize in 1994, the “Enotecnici” Prize in 2004, the Rudolph Hermanns Foundation Prize in 2011. Winner of the “2013 Best Paper Award” from the American Society of Enology and Viticulture. Peer reviewer for 21 scientific journals, Associate Editor for the Amer. J. Enol. Vitic. and Associate Editor for the Australian Journal of Grape and Wine Research.
The seminar reproduced in this video was presented at the 1st Spanish edition of Enforum Web (5-7 May 2020)