A trailer-load of built-up dry fuels from the woodland floor. Credit: The Quoin team.
After the material has burnt for a few hours, we quench the embers from beneath with 1500L of water. Credit: The Quoin team.
Biochar is a rich organic material that can be utilised in a range of ways with multiple benefits. Credit: The Quoin team.
We put dry material in a 1800-litre kiln and light it from the top. Credit: The Quoin team.
Benefits
Fire mitigation
Makes room for regrowth and animal movement on the woodland and forest floor
Carbon sequestration
Expedited drop-loo composting
Boosts water filtration
Boosts soil quality
Sourcing locations
Woodland and forest
Deployment locations
Overgrazed areas of high macropod manure load
Stocker’s Bottom drainage channels
Long-drop toilets
Aim
Taking the build-up of dry fuels on the woodland floor and turning it into a multiplier of other opportunities.
Context
Biochar is made by pyrolysis, which is the process of taking organic matter like wood chips and heating them in the absence of oxygen. The result is a carbon-rich charcoal that doesn’t degrade for hundreds of years.
Biochar is considered a carbon-negative process because it takes wood that would otherwise decompose and locks away this carbon for centuries. It has a whole range of uses, but is most commonly added to soil to improve nutrient retention, water filtration and habitat for microbes.
How we make it
First, we collect dry branches that are too small to develop a hollow that can serve as animal habitat and too dry for fungi to inhabit. Then we put this material in a 1800-litre kiln and light it from the top. As the material burns, we add more on top, starving the already burning fuel of oxygen.
This continues for a few hours, until all the embers have a clean white ash layer. At this point, we quench the embers from beneath with 1500L of water. The rush of steam through the embers increases the porosity of the resultant charcoal, improving its surface area and effectiveness as an amendment.
How it’s used at The Quoin
Biochar has the dual benefit of clearing flammable dry fuel loads from the land and creating a rich organic material that can be utilised in a range of ways with multiple benefits.
We use biochar in our drainage channel and stream remediation work. If you read about our leaky weirs experiments, you’ll know we are experimenting with natural barriers to slow the flow of water at The Quoin. We add biochar to these physical barriers too, because it can absorb the nitrogen from animal scat out of the water stream. What’s more, in major water events when manure is ferried across the site, the biochar moves too. This is a boon because together, the manure breaks down far more quickly.
Another use is long-drop toilet composting on the property. Drop toilets traditionally use sawdust, which has a 30:1 carbon-to-nitrogen ratio. But biochar is at least a 100:1 carbon-to-nitrogen ratio, which means a bucket of biochar is 300% more effective at composting waste and suppressing odours.
We use the water byproduct that comes out of the kiln too, as it’s full of potassium and wood vinegar, and perfect for fertilising plantings and encouraging seed germination.
It’s this fourth benefit that we are most excited about.
We’re in the process of collecting seeds from The Quoin, to be germinated into seedlings in the nursery, and then replanted on the property in our restoration efforts. Wherever possible we’ll use seeds from the property so the seedlings will be adapted and suited to the landscape. But we’re not stopping there. By supplying our nursery team with biochar, to mix with potting mix, we’re effectively using soil from the site too, giving our seedlings the best chance of survival.