Field of Mars is the Keith Tulloch Wine home vineyard. Planted mostly to over 50-year-old vines on alluvial soils in Pokolbin, it rubs shoulders with some of the Hunter’s most revered semillon sites. Sustainability is a key driver of the estate, from the farming to re-establishing native scrub to using only recycled packaging for their wine. The site is run by vineyard manager Brent Hutton, with it producing premium single block wines in the Field of Mars range.
Keith Tulloch founded his eponymous winery in 1998 after considerable experience at home and abroad. It was at a time when the famous Tulloch family winery was under outside ownership (it was bought back by Jay Tulloch in 2001). Tulloch works across seven vineyards, with the home site the Field of Mars Vineyard, with 5.4 hectares of vines planted to semillon, chardonnay, shiraz, roussanne, marsanne, viognier and touriga nacional.
The site was first planted in 1968, with half a hectare added from 2014 to ’17. Tulloch regards the vineyard as one of the best for semillon in the Hunter, and it’s a site he’s lovingly restored with the help of his father, Dr Harry Tulloch (a viticultural research scientist), since its purchase in 2008. Today, the vineyard is managed by Brent Hutton who farms with sustainability as a core principle.
“Within our business we have a wide range of sustainability initiatives, which fall into the three key areas of soil health, biodiversity and emissions reduction,” says Hutton. “These principles guide our decision making and have led to a complete overhaul of the way we operate since 2017. We now use only organic fertiliser in the vineyard, recycling marc and chicken manure instead of chemical fertilisers which have harmful impacts on soil health and emissions.”
Hutton points out that the Field of Mars vineyard neighbours some of the most iconic semillon vineyards in the world, including Braemore and Tyrrells HVD. “We share our sandy alluvial soils with those great sites,” he says. “The age and clone of our semillon is vitally important, but so is the vineyard management, so the way we try and promote healthy soils and biodiversity makes for healthy vines and that creates the magic we see as the final product.”
Manure, compost and hay mulch are applied to the soil, which now teems with earthworms and beneficial microbes. A range of winter cover crops are grown in the vineyard midrows, which Hutton says achieves many of their sustainability goals. “These crops provide habitat for native beneficial species, sequester carbon from the atmosphere and replenish soil nitrogen. Currently, we are using several different annual and perennial under-vine species of grass, clovers and flowers to increase the soil’s organic matter naturally, reduce our water usage and hopefully eventually completely eliminate the need for herbicide within our vineyard.”
“When spring comes around, we terminate the midrow cover crop mechanically with a crimper roller, which makes a thick layer of organic matter on the vineyard floor.”
The heavier clay soils of some blocks are mulched rather than cover cropped, which helps to suppress weeds, increase organic matter and help retain water in the soil. Hutton notes that previous management employed heavy cultivation and under-vine herbicide treatments, which left the site with compacted, bare and poor soils. “Now we rarely break the earth at all, only once annually when we resow in our winter cover crop,” he says. “This allows the midrow and under-vine cover crops to replenish the soil and rebuild structure. When spring comes around, we terminate the midrow cover crop mechanically with a crimper roller, which makes a thick layer of organic matter on the vineyard floor.”
Led by production manager Alisdair Tulloch, areas that were once nuisance zones full of undesirable weeds are now significantly important biodiversity corridors, with a predominance of casuarina trees diversified by planting other arboreal species and spreading seeds of native grasses and other beneficial plants. These corridors benefit native animals and insects, while they also act as wind breaks to protect the vines, which is especially important at delicate times like flowering. Native garden beds adjacent to the vines are planted to flowering species, becoming havens for beneficial native insects, birds and micro-bats, helping to deplete pest insect populations.
“Every year, we plant hundreds of native trees from a local nursery in the riparian areas [those adjacent to waterways] and tree lines surrounding the vineyard blocks to further enhance the local biodiversity,” says Hutton. “These parts of our vineyard are reserved particularly for this purpose and total several hectares. We see our vineyard as a piece of the natural environment, so these programs are about harnessing the benefits of that environment and using them practically, while also giving back every year to the land.”
Insecticide use has been dramatically reduced due to the increase of predatory populations. “During the last growing season, we didn’t have to spray for any of the pest insects we find in the local vineyards,” says Hutton. “This was due to the hugely improved level of beneficials we had in our canopy from the old orb weaver spider to praying mantis and shield bugs keeping pests at bay, thanks to our proactive approach to promoting biodiversity on our sites.”
The quest for sustainability is also part of larger mission beyond fruit and wine quality. “Keith Tulloch Wine takes very seriously our impact on the environment, both onsite and throughout our entire supply chain,” says Hutton. “This desire to run a sustainable vineyard and wine business led to us becoming the first Hunter Valley winery to be certified carbon neutral by the Australian government’s ‘Climate Active’ program in 2019. We’re only the second vineyard or winery in the country to achieve this certification.”
There are current preparations for planting another hectare of vines in 2022, including a massal selection of semillon and three blocks of high-density chardonnay. “This is the next great project for the Field of Mars vineyard, and we have purchased new smaller tractors and implements to work with the smaller row widths and headlands,” says Hutton. “The older parts of the vineyard have the original steel pickets and wire from the mid-1960s still in place, so each year we have a lot of re-trellising work to do as well as improvements in irrigation. Each year, we’re greatly improving each block one by one.”
This restorative work is seeing dead wood removed from the old vines, then retraining, which gives the vine a more productive life and eliminates any trunk disease, a persistent problem. It also provides the benefits of a large and deep-reaching root system that can take advantage of the increased soil health with its enhanced populations of symbiotic fungi and microorganisms. Those vines also have better access to groundwater, a distinct advantage in the heat of the Hunter, especially as some of the older vines are still dry grown.
Hutton notes that while it is hard to pin any one viticultural practice to improvements in fruit and wine quality, the fruit is consistently more balanced with good flavour at lower sugar ripeness. “We have been very impressed with the flavour of the semillon, chardonnay and shiraz at lower alcohols of 11–12.5% than in the past when they might have tasted a bit too green at that point, and we have proudly made wines within these levels from 2021,” he says.