Unravelling the interaction between the application of municipal solid waste compost and mechanical hedge pruning in vineyards: effects on the vegetative and reproductive growth, and grape and wine quality of Sauvignon from Lisbon wine region

In the last seven years, mechanical pruning has gained increasing relevance in Portugal, and alongside soil organic amendment, it contributes to the sustainable intensification of viticulture. The aim of this work was to study the interaction between increased bud load due to mechanical pruning and enhanced soil fertility due to progressive doses of municipal solid waste compost (MSWC), and their effects on reproductive and vegetative growth, as well as wine quality. A trial in a Sauvignon vineyard was implemented in the Lisbon wine region (Portugal). Mechanical hedge pruning was compared with hand spur pruning and the following four MSWC doses were applied for three consecutive years: 0 kg ha–1 year–1 (M0; control), 5000 kg ha–1 year–1 (M1), 10000 kg ha–1 year–1 (M2), and 20000 kg ha–1 year–1 (M3). Mechanical pruning significantly increased yield and reduced vine vigour and vegetative growth, whereas MSWC had no significant effect on yield, but showed a tendency for higher vigour and vegetative growth. Mechanical pruning increased not only yield, but also wine alcoholic strength. Both factors had some effects on wine colour, which were not perceived by the tasters. Although the tasters differentiated the wines from the different treatments in some parameters, no significant differences were found between treatments in global appreciation. The interaction between treatments was not significant in any of the analysed parameters. Although MSWC had no significant effects on yield or quality, its potential positive effects on soil fertility make it an interesting tool for enhancing vineyard sustainability, especially when combined with mechanical pruning.