Good to grow

Biochar test garden aims to enrich poor Newfoundland soil

Published on September 22, 2012
Lori Heath stands in front of Common Ground’s biochar test garden in the St. John’s Safer Soil demonstration garden off Barnes Road.
— Photo by Sarah Smellie/Special to The Telegram

It’s pretty unusual to see a healthy crop of oats growing in a downtown St. John’s garden, so it’s no surprise that Lori Heath’s oat plots at the Safer Soil demonstrations gardens, in the field beside the Lantern, off Barnes Road, were drawing a sizable crowd at last week’s Open Garden Day.

What’s really unusual is the medium she is growing them in.

Heath — the project co-ordinator at St. John’s Safer Soil and Common Ground, the umbrella organization that oversees Safer Soil and the biochar test garden — planted 12 small, raised beds of oats at the beginning of the season. Now, nearing the end of the prime growing weather, some beds’ crops are noticeably taller than others.

“Some are planted in regular old rocky Newfoundland soil,” she says, gesturing to the weaker-looking crops. “And some are planted in soil that’s been amended with biochar.”

Biochar is a special kind of charcoal made from a process called pyrolysis, which consists of slowly burning organic matter in a closed, low-oxygen environment. The result is a pile of tiny pieces of grey-black charcoal, which are light and porous.

“If you looked under a microscope at each piece,” says Heath, “you would see lots of holes, which means lots of surface area for microorganisms to thrive. It can dramatically increase soil fertility. It also reduces water and fertilizer requirements.”

Though the Common Ground garden is Atlantic Canada’s first field trial, biochar has been used to make marginal soil usable for hundreds of years. Pre-Columbian Amazonians are believed to have smouldered organic matter in dug-out pits to make biochar for their soil.

The Common Ground garden is a bit more advanced. Heath used biochar that was shipped in from Saskatchewan. She also has professor Bob Helleur, from the chemistry department at Memorial University, on board as the project’s scientific adviser and support lab. He’s been keeping tabs on the soil quality and will measure and test the crop yield come harvest time.

Helleur has a lot of experience with biochar.

“There’s a huge push right now to use biochar as a way to sequester carbon,” says Helleur.

Touted by prominent environmentalists such as James Lovelock and NASA’s James Hansen, biochar has been making worldwide headlines for its potential to reduce greenhouse gases in the atmosphere and improve soil quality.

Decaying organic matter and soil releases huge amounts of greenhouse gases into the atmosphere, but soil amended with biochar can store these gases in the ground for thousands of years.

As an added bonus, biochar also seems to make certain types of unusable soils fresh and fertile.

“Newfoundland soil is pretty bad,” says Helleur. “With the Safer Soil project, we’re looking at how good adding biochar to Newfoundland soil really is.”

Helleur also received a grant from the Harris Centre-MMSB Waste Management Applied Research Funds to look at what fraction of the garbage heading for Robin Hood Bay could be diverted and used to create biochar.

“My project was to divert waste, like paper and yard waste and cardboard, and then determine which is the best source for biochar,” he says. “A grad student and I went through the non-food garbage at the university, the yard waste in the Churchill Square area and the garbage destined for the landfill. We sorted it into different streams, like white paper, newsprint and so on. And then, using slow pyrolysis in a lab-scaled tube furnace, we made and analyzed the biochar to determine which waste stream made the best biochar.”

In the end, soiled newspaper, grass cutting and demolition wood were the top three producers.

“So, the usable amount of the waste going to the landfill is certainly significant,” he says.

Helleur is on board with the burgeoning global biochar movement, and says the tiny grey pellets have a lot to offer.

“I see big promise for biochar, in general,” he says. “Right now, I’m working with the Department of Natural Resources and the Kruger Pulp and Paper Mill in Corner Brook to look at biochar production as a commodity. For example, the sawmills have no place to sell their sawdust and their chips in central Newfoundland because the Grand Falls-Windsor mills closed. So the sawmill is very interested in finding something to do with all of this waste.”

The oats growing in the biochar-infused soil beside the Lantern certainly seem to appreciate the stuff. They’re much taller and stronger-looking than the oats in the plain Newfoundland soil, and even those that have been treated with compost tea.

“We would like to start making it ourselves,” she says. “But that’s still a ways off. For now, we’re looking at holding a few workshops and show people how they can use biochar in their own gardens and properties. Soil is so important. It’s the first step in producing food, and the soil quality here is so low. So it’s really crucial to explore these ways to improve the soil here.”

Heath was planning to begin harvesting the biochar test garden last week.

“I’m going to have a lot of bowls of oatmeal to eat,” she says, laughing.

Twitter: @tara_bradbury