Olive trees on South Australia's Fleurieu Peninsula turned into biochar for vineyards' health at McLaren Vale
The portable Tigercat 6050 Carbonator used by Peats Soil & Garden Supplies to burn the feral olive trees from the Fleurieu Peninsula national parks. Inset: Loading the Tigercat with olive trees.
Images courtesy Peats Soil & Garden Supplies.
A group of wine industry environmentalists in 2021 turned feral olive trees removed from Fleurieu Peninsula national parks, south of Adelaide, into a biochar product to boost the health of McLaren Vale vineyards.
The carbon recycling project was driven by Biodiversity McLaren Vale to clear problem olive trees from Onkaparinga National Park and Glenthorne National Park/Ityamaiitpinna Yarta. The olive trees were then burned at 500C in an environmentally-friendly machine called a Tigercat.
Fifth-generation winemaker of Chalk Hill Wines and McLaren Vale Distillery and a Biodiversity McLaren Vale founder Jock Harvey was heavily involved in the project: “We wanted a methodology that would work with biodiversity easier, be less time consuming and more effective. Once we removed the woody weed waste we weren’t just incinerating it into atmospheric gases, but we could use the biochar methodology to end up with a stable form of carbon that stays in the soil.”
Early biochar trials on local vineyards were showing promising signs of improved vine health. Biochar retained nutrients and moisture. It built vineyards’ resilience in the vineyard and cut fire risk from extremely flammable olive trees. The South Australian environment and water department, Biodiversity McLaren Vale and Peats Soil and Garden Supplies were among those working together in the national parks project.
Peats Soil managing director Peter Wadewitz had dedicated almost 50 years to supplying compost, mulches and recycled organic resources to the horticulture and garden industries locally and nationally. Ten of those years were spent experimenting with biochar.
Wadewitz introduced Biodiversity McLaren Vale to the portable Tigercat 6050 Carbonator, imported from the United States. The large machine burned organic matter at 500C and reduces its volume by up to 95%.
Wadewitz said there was great potential for commercialising biochar by inoculating or “charging” it with compost. The result was a valuable product that can then be sold to commercial partners including local vineyards, with potential also for fruit and vegetable crops. He said the biggest challenge with biochar was the cost, with a high price point of around $1000 per tonne making it uneconomical for farmers: “There are many biochar plants that are not far from coming online. Once that happens the (price) curve will soon come down.”
The Biodiversity McLaren Vale group and Peats Soil’s goal was to continue working towards creating a circular economy.
