Vineyard trials help build resilience

The Barossa Grape & Wine Association (BGWA) has set up three demonstration vineyards as part of its ongoing Creating Resilient Landscapes initiative, with funding from AGWA’s Regional Program.

The idea is to 'show not tell' growers and winemakers how modern viticultural techniques can boost soil health for more consistent yields, reduce traditional inputs and potentially improve fruit quality.

'One or all of these outcomes can improve vineyard resilience and profitability – and that’s vital for a sustainable wine industry', said BGWA Viticultural Development Officer Nicki Robins.

'In preparation for the hotter, more extreme weather that’s predicted, by improving soil management, growers can combat the highs and lows in yield due to seasonal influences. This results in more consistent production and therefore increased vineyard profitability.'

The trial blocks at Light Pass, Vine Vale and Ebenezer are each between 0.6 and 0.8 hectares – large enough for a harvesting ‘cut’, so when the grapes are made into wine the Trial can be kept separate from the Control (the grower’s current practice).

At one vineyard, only 40 hours of irrigiation was used on the Trial rows, compared with 144 hours on the Control. These savings were achieved by laying mulch under vines and applying irrigation based on canopy health (condition of tendrils and shoot tips) as opposed to a regular calendar schedule.

'The yield is slightly lower on the Trial rows, however the winemakers have reported improvement in fruit quality that may, down the track, result in a higher grade for the grower – as well as the money saved on water and pumping costs', Nicki said.

'To improve soil condition, we’ve laid Jeffries Dura Mulch under vine, which has a 5-7 year lifespan and ongoing soil health benefits as soil carbon levels build up. In addition, all the vineyards have mid-row swards, which are important for beneficial microbes to feed on and create "pathways" for water and nutrients to enter the soil.

'We’re also trialling different mid-row grasses. The idea is to find grasses that suit the vineyard’s soil type so they don’t rob the vines of water during the growing season but still provide infiltration benefits. Native grasses such as Wallaby Grass are ideal, as they switch off when the vines switch on.'

Nicki said that while growers couldn’t influence seasonal variability, they could adopt better soil management practices that would result in more consistent, sustainable production and better profitability.

With rising water and electricity costs, improved soil health would also reduce growers’ reliance on these increasingly scarce resources.

'Improved soil condition improves porosity, aeration and structure, which reduces the need for irrigation and combats problems such as compaction and salinity', she said. 'It also significantly reduces reliance on chemicals, fertilisers, fuel and machinery used for operations.'

The BGWA hopes to set up three more trial sites with funding from AGWA’s 2015/16 Regional Program.

For more information, contact Nicki on 8563 0650 or nicki@barossa.com