New Zealand biochar users have provided some valuable insights to a roving Nuffield scholar studying the use of the charcoal product in the primary sector around the world.
Luke Breedon of Wessex in the United Kingdom is visiting Scandinavia, Europe, the United States Australia and New Zealand to examine the potential, both realised and unrealised, for biochar’s use in increasing agricultural productivity.
Biochar is the charcoal produced through the process of pyrolysis, the burning of material in an oxygen-free or air-limited environment.
Found naturally in soils as a result of historical fire cycles, it does not break down easily and offers a means of enhancing soil structure, and sequestering carbon.
It is one of the few negative-emissions technologies recognised by the Intergovernmental Panel on Climate Change, storing up to half the carbon in its source material for hundreds of years. It has also been shown to improve soil structure particularly in sandy or highly friable soils.
Breedon spent his time visiting the North Island for his study tour.
He said his impression is that New Zealand farmers and growers are tending to dive in and use biochar, focusing more on its soil improving attributes than its carbon sequestration capability.
“Having been to Europe and the United States, there are quite a few big companies with grants and funding, versus people actually using biochar.
“Here in NZ there are guys on the ground actually using it, and not necessarily concerned about the carbon value so much.”
He also had the sheer volume of raw material available here pushed home to him when he set up camp at the Waikari River mouth in Hawke’s Bay, only recently opened after being inundated by forest waste during Cyclone Gabrielle.
“There was still plenty of material still piled up around the place.”
His interest in biochar began after he and his wife started a barbeque charcoal business, after several years involved in the arable cropping sector.
His business, Slate Hill Charcoal, offers a more sustainable option to other charcoal products on the market.
He soon saw his interest turn to the opportunities biochar provided to help improve soils and primary production.
“Here I have also found most people using it are also often making it themselves. I visited the property of Dale Redpath in Opotiki, who is making it from mānuka scrub and putting it back into the soil and replanting trees.”
While visiting he got a hands-on opportunity to turn some of the scrub into biochar, making about 425 litres in four hours.
Te Puke-based post-harvest company Trevelyan’s also hosted Breedon, where the company is researching the potential for biochar and regenerative orchard practices on soil biology.
One company he visited, SoilPro, was sourcing carbon boiler ash as a biochar source, aligning with market gardeners to supply product to add to soils. Growers have claimed to enjoy a 50% reduction in their usual fertiliser needs.
Another company, the Good Carbon Farm, is providing free biochar to schools and community gardens to incorporate into compost and soils.
“It has been great to visit a place where people are actually using it. There is a lot of talk about it in Europe, a lot of conferences on it, but not a lot of actual use.”
Breedon is also visiting Australia, where research has been done that indicates feeding biochar as part of a feed ration can increase milk yield in dairy cows while also reducing methane emissions.