The relative sustainability of organic, biodynamic and conventional viticulture

Abstract

Organic and biodynamic viticultural practices have received much attention, especially by premium grape growers worldwide. This growth is coupled by a demand for organic and alternative methods of agriculture due to increasing consumer concern regarding food quality and safety. The aim of this study was to compare vine performance, berry composition and wine quality of four management systems: Biodynamic (BD), Organic (ORG), Low Input Conventional (LCON) and High Input Conventional (HCON). A six year trial was established in 2008 in a commercial vineyard located in McLaren Vale, Australia on Cabernet Sauvignon (Vitis vinifera L.) grapevines. Measurements of vine performance, berry composition and wine quality were used to compare management treatments. No consistent effect of management system was seen in the first two season’s results. However, in the remaining four seasons vine vegetative and reproductive growth was lower for ORG and BD treatments (5-15%) compared to LCON and HCON. No significant differences were found between treatments for traditional berry compositional measures such as total soluble solids, pH, titratable acidity. However, total anthocyanins or phenolics did vary between ORG, BD and CON treatments. Wines produced from the trial were assessed by an expert panel of winemakers from the McLaren Vale wine region. No differences in wine quality were observed between management treatments in the 2009/10 season. In all the following seasons ORG and in particular BD wines were described as being more rich, textural, complex and vibrant than LCON and HCON wines. Changes in fruit and maturity characteristics were also observed and the relationships between these characters and vine performance will be presented. BD and ORG management can significantly alter vine performance and wine quality.