Wine crops boosted, and costs cut, with recycled organic composts
Disappearing wine regions, altered grape flavours, and unhealthy soils that struggle to retain moisture – these are just some of the possible effects of climate change on the world of winemaking. But Victorian vintners (makers and sellers of wine) are turning to an innovative take on an age-old solution to improve soil health, grape quality, and climate resilience — recycled organic composts.
Sustainability Victoria funded three projects in Victoria’s wine regions to encourage vintners to use more recycled organic composts and grow the market for recycled organics.
New equipment helps produce climate-resilient vines in Heathcote
Sustainability Victoria provided $278,600 to 64 vineyards across Victoria’s Heathcote region for shared equipment. This equipment makes it easier and faster to spread the compost under the vines.
The project also connected the vineyards with compost provider BioMix. BioMix supplied discounted high-quality recycled compost, using food and garden waste collected from kerbside FOGO (Food Organics Garden Organic) bins in inner-city Melbourne.
Madeleine Marson from Vinea Marson Winery explains how compost improves soil's ability to capture water and helps produce climate-resilient vines that deliver more consistent fruit in the face of extreme heat.
‘This means that the vine is better able to cope with the stress of extreme heat events physiologically,’ she says. The project has also diverted 5,210 tonnes of green waste from landfill.
‘So, when you are putting out your green bin in Melbourne or wherever you live, you can see the end product – that it’s going back to our vineyard to improve our soil health,’ explains Madeleine.
Hugh Jones, from Heathcote winery Humis Vineyard, says that while the group has just completed the first 15 months of the 5-year project, the results are so far encouraging. ‘We’ve spread something like 2,600 tonnes of compost, which as a region means we’ve saved the 5,250 tonnes of greenhouse gas emissions.’
Hugh says that while there has always been an appetite for using compost in their region, it’s been difficult to do it at a scale due to cost and availability of equipment.
‘The size of the spreader means vineyards can distribute more compost in less time, which also saves on labour costs,’ he says.
‘So, when you are putting out your green bin in Melbourne or wherever you live, you can see the end product – that it’s going back to our vineyard to improve our soil health.’
Heathcote Field Day brought together over 90 Victorian winemakers from Gippsland, Rutherglen and the Yarra Valley. They learnt about the benefits of using recycled organic composts and the technology and equipment that simplifies its application. Proof of product is essential to new uptake for recycled organics
Sustainability Victoria’s Markets Acceleration Manager Shannon Smyth explains that it’s not just cost and accessibility that are barriers to the wider uptake of recycled composts in the wine industry.
‘A lack of knowledge and confidence in using recycled organics is also an issue,’ says Shannon. ‘That’s why we build in knowledge-sharing opportunities into Sustainability Victoria’s grant delivery. The Heathcote Field Day was attended by winegrowers as far away as Gippsland, Rutherglen and the Yarra Valley.’
‘It was an absolutely smashing day,’ says Hugh. ‘We had a really big crowd with over 90 people, not only from the Heathcote region, but also people coming from regions across Victoria. That allowed us to share our stories with a broader audience, and to create solutions to problems that we have in our vineyards together.’
Andrew Dougall, Organics Industry Development Lead from SV, presented at the field day. He was encouraged by the interest from vignerons in the circular economy.
‘I have never seen so many conscientious note takers at a field day; these vignerons are certainly serious about the circular economy and the sustainable outcomes it delivers,’ says Andrew. ‘In fact, more 88% of survey respondents who attended the event reported that they were likely or very likely to try recycled organics on their vineyard.’
Hugh Jones and Stephanie Doubadon at the Heathcote Field Day Using composted green waste as an under-vine cover can reduce the need for herbicides
In the Macedon Ranges, Sustainability Victoria provided $15,019 to Melbourne Water to lead a 3-year project to demonstrate the benefits of using composted recycled urban green waste as an under-vine cover. Melbourne Water's aim was to encourage other cool climate vineyards to use composted organics.
Lead researcher Erika Winter from GrapeLinks explains that they tested processes and results at two vineyards using recycled organic compost and mulch in the vine rows. They compared these to a control row that used standard methods like brush cutting and herbicides. They used electronic data loggers to monitor the temperature in the vine canopy and soil, and they checked the grape quality and yield at each annual harvest.
Results showed that weed control was excellent in the vineyards using composted mulch. This meant a summer herbicide application wasn't needed.
Soil moisture under (composted) mulch was high in summer, reducing the need for heatwave emergency irrigations. However, this was not the case under the fine compost.
Lab testing found that composted mulch improved nutrient levels in petioles (the stalk that joins a leaf to a stem), vine vigour, and yield (though yield varied year on year due to different make-up of the recycled organics).
Using organic recycled mulch can improve grape flavour and reduce costs for winemakers
But to the all-important question – did the grapes taste better? Their ripeness at harvest (the measure of sugars in the juice, known as ‘brix’) was slightly enhanced by mulch and compost. Titratable acidity, colour and phenolics were found to be higher with recycled composted mulch than over fine compost or the control.
The researchers suggested that custom-made recycled organic composted mulches and composts for viticulture could be the next step in seeking improvements for both grape growers and the organics recycling industry.
Through this project, Melbourne Water has developed an online cost calculator. It helps growers determine the amount, and cost, of compost needed per hectare at various row widths and application rates of product.
'We’ve spread something like 2,600 tonnes of compost, which as a region means we’ve saved the 5,250 tonnes of greenhouse gas emissions.'
Longer growing seasons for vineyards a direct result of compost spreading equipment
Yarra Valley vineyards are exploring how to simplify logistics so that viticulture, orchards, and broad acre farming can use more recycled organic compost.
The project was led by Total Viticulture Solutions (TVS) with $50,000 funding support from Sustainability Victoria.
The trial project updated a wheeled bobcat to a Posi-Track loader to increase spreading efficiencies by up to 70%, explains Cameron McIntosh from TVS, decreasing the overall cost of applying recycled compost and mulch products to vineyards.
While costs have been increasing across the viticulture industry, Cameron says that this project has lowered costs, ‘because I can load that machine at a faster rate, basically. So, I'm spreading for the same cost now as I was 6, 7 or 8 years ago.’
Cameron says that costs of spreading equipment and labour can be a deterrent to smaller vineyards. ‘Smaller customers can’t afford those. But if a contractor like myself can offer it to the entire market, then it’s a solution for the entire industry.’
The loader has allowed them to extend the season as well. They can continue to work in wet and muddy weather, conditions the Yarra Valley is renowned for.
‘We’ve seen phenomenal things through compost,’ explains Cameron. ‘It’s a resource available to everybody and not at huge cost. It’s a phenomenal product and from what we're seeing in the guys who are using it, the quality improvements in their vineyards are astonishing.’