This project will provide information on the best ways to manage low winter rainfall using existing vineyard infrastructure and how modifications to irrigation systems may result in better outcomes for grapegrowers under climate change.
Australian winegrowing regions are expected to experience warmer and dryer winters due to climate change. In most premium regions, the vines rely on a full soil profile at the beginning of spring to supply water for canopy growth and development into summer. Previous work has demonstrated that the most common approach of filling the soil profile in spring is potentially the worst option for growers following a dry winter, with negative effects on vine growth and yield and on grape and wine characters.
Existing field infrastructure will be used to explore alternative approaches to maintain grapevine productivity during dry winters. These include: (i) changing irrigation volume, (ii) modifying the time of soil drying and wetting, refilling soil profile with drippers earlier in autumn or at mid-winter, and (iii) altering the soil wetting pattern using alternatives to the mini-sprinklers and drippers, such us buried mid row drippers and double drip lines. In addition, both water sources (rainfall and irrigation) will be investigated to see if they supply additional nutrition to the vines (e.g. nitrogen in rainwater) that could impact on growth and productivity.
The project will develop guidelines for grapegrowers to establish and manage their vineyards to maintain productivity under conditions of reduced winter rainfall. This project will support grapegrowers and winemakers in premium Australian growing regions who have traditionally relied on winter rainfall to support most of their canopy growth and development.