A new partnership between Rosemount Wines and Peats Soil and Garden Supplies is set to take the waste out of grape marc. Under the plan, Peats is undertaking composting trials using Rosemount's grape marc for the wine company to spread on its vineyards.
Rosemount regional vineyard manager Kym Ayliffe said the program would save the company money and reduce waste from the winery.
"I think the beauty of the whole thing is that material under the vines comes from the vines," he said.
"It's been done before, but hasn't been composted in a professional manner."
Mr Ayliffe said the program replaced the previous system of collection of marc by Tarac. "Tarac turned around this year and said it couldn't take grape marc from people unless they were prepared to pay cartage," he said.
"If you're not getting anything from it, it's not cost effective. But this year, we're going to be stuck with 2000 tonnes of grape marc at this site.
"Relying on past trials with Peats Soil and Garden Supplies, we're looking to cart our grape marc down to a site at Langhorne Creek where it will be stockpiled and combined with Nitra Mulch and chicken manure.
At completion of the program, we'll spread it on our vineyard." Mr Ayliffe said he expected the compost would last four to five years and reduce water inputs.
He said other positives of the program included improved soil amelioration and encouragement of vine roots just beneath the soil surface.
"Normally it's too hot for these roots - the soil usually heats up too much near the soil surface - but that's where the best aeration is," Mr Ayliffe said. "By using the compost we're allowing our roots to get into the zone of improved nutrition."
Peats sales manager Chris Abbie said the grape marc, which consists of material such as grape seeds, old cane material, bunch stems and grape skins, was combined with Nitra Mulch and chicken manure during the blending process.

AT A GLANCE  Program projected to save money and reduce waste in the vineyard.  Positives include improved soil amelioration and encouragement of vine roots.  Langhorne Creek vineyard achieves 30pc increase in bunch weight.  Compost increases nutrition in root zone.

Mr Abbie said the final product contained good carbon organic matter, which encouraged worm activity. Worms help by breaking down matter and returning it in a usable form to the plant.
Mr Ayliffe said he was a strong advocate of compost which had enabled him to wait three weeks before watering composted blocks this season.
"We are able to utilise winter water stocks. And later in the season, when we are applying irrigation water, there's better return on that water," he said.
"And another positive is that in spring when we put compost on vines that were struggling at Langhorne Creek - although a bit heavier than the recommended rate - we had a 30pc increase in bunch weight. "That means we've paid for half the capital outlay in one year."
Mr Abbie said Peats was running similar programs with other producers in the Langhorne Creek region. And he said three other wineries were supplying their grape marc to Rosemount for inclusion in their program.
Expressions of interest have also come from other SA growing regions. He expected marc composting for mulch would be incorporated into vineyard regimes around Australia in the future.
"Fortunately there are people out there like Kym who are switched on enough to see the long term benefits of programs like this," Mr Abbie said.
"There is the choice of marc becoming a waste material or a raw material with other uses."