Niagara-on-the-lake winery finds notable results from the use of a soil amendment created on-site
Dean Stoyka heard the neighbour- hood talk about his biochar experiment: how Stratus Vineyards had made a mistake three years ago, promoting such a relatively young, inexperienced staff member to vineyard manager.
But Stoyka and J-L Groux, a winemaking veteran from the Loire Valley in France who is Stoyka’s boss, like the results. At the Niagara- on-the-Lake winery, they’ve experimented since 2015 with char made from weathered vine trimmings as a soil amendment.
They relied mainly on advice from members of a seasonal, Jamaican workforce. These employees have experience back home making charcoal for cooking fuel.
In Ontario, they compost the black, chunky char with grape skin and seed residues from the winemaking. They spread this biochar in the autumn on blocks of poor-yielding vines. The following spring, they work it with chicken manure into the root zones between the rows.
Plant response in some cases has been startling. The team has witnessed a tripling of yield in one block of poorly performing Syrah-variety grapes, Stoyka said during a recent interview. He pulled an iPhone from his pocket and keyed up harvest data to prove his point.
The move fits the 13-year-old winery’s ambitious, environmental profile established by Stratus CEO David Feldberg. The four-storey winery and retail store was the first winemaking facility in the world to gain a Leadership in Energy and Environmental Design certification, reports a 2010 Wine Spectator article posted on the Stratus Vineyards website.
The building features geothermal heating and cooling, a super-insulated roof, and gravity-flow processing of juice and wine. In the vineyard, the team uses electrostatic sprayers to decrease the use of both water and fungicides.
Stoyka joined Stratus Vineyards eight years ago following a Niagara College work placement with the winery. He took on the vineyard manager job three years ago. When he raised the subject of biochar in his first year as vineyard manager, Groux had obvious questions but came back and said, “Let’s go for it.” Stoyka had expected as much.
“We’re using all these green technologies; we have a green committee at the winery; so, I said, this is another way,” Stoyka said.
“How do we recycle all our products from our vineyard and not waste them?” he asked.
The high-end winery retails much of its product at the elegant building where Groux and Stoyka – part of a crew of five full-time production employees and a seasonal workforce of eight staff – grow grapes and make wine. In a small reception room used for special events stands a metre-tall clear cylinder on a sideboard. The piece is loaded with Stratus-made char and often becomes part of customer conversations.
“Any single piece of green technology is not super interesting on its own,” Stoyka said. “But when you take it as a whole, when you have a story, all of a sudden it says, ‘Wow, these guys are really trying to do something different.’”
Stoyka determined from his research that no reliable guidelines for application rates exist and purchasing commercial biochar can be expensive. Advised by the Jamaican crew, the team came up with a plan to make char in an earth-covered oven with very little smoke or odour. They worked with an $800 budget to buy two truckloads of topsoil and a pile of weathered straw.
Instead of simply burning vine trunk trimmings in open fires, as is typical in the Niagara Region, they stockpile the material as pruning season begins in mid-March and burn it, usually in April, in the centre of the 62-acre property. Because the pyrolysis (i.e. decomposition through high temperatures) to make char requires thermal degradation of biomass in the absence of oxygen, the team covers the mass first with straw and then soil and burns it over three days. The mounds resemble beaver lodges. The team spreads the biochar, usually in early October, between the harvests of white and red grapes.
“The research is not concrete yet on biochar,” Stoyka said. “There are disagreements on how much you need, how much it’s acting, how long it’s acting in soil and how much nitrogen it’s capturing. There’s not a real consensus,” he said of the research.
“I’m only putting biochar on in weak spots in the vineyard, places we know we have low yields. … In the areas where I’ve had traditionally very low yields, those yields are starting to bounce back in a huge way,” Stoyka said.
He can’t exactly say why his yields have improved because he has not run a controlled experiment. But Stoyka is convinced the compost and char have something to do with reviving one block of failing Syrah vines. Plants which had been yielding as little as half a tonne to the acre in 2013 came in last year at a tonne and a half.
“Something is happening there,” he said to Better Farming. “Our weak areas are responding in a way that we’ve never seen before. I can’t attribute that exclusively to biochar. The compost is going there and also the straw. You can’t say it’s just the biochar acting, but we’ve had a huge impact and all of a sudden yield is looking good.”
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