Growing with Biochar
USDA SARE grant project

KAW Valley Biochar
Lawrence, Kansas

David Yarrow checks smokeless fire
55-gallon TLUD barrel burner
Biochar on the Farm
Initiative to Give Grower Guidance

by Tara Maxwell
Acres USA, The Voice of Eco-Agriculture
May 2013 Vol. 43 No. 5

click for 3-page .pdf

You most likely heard of biochar, but you probably have lots of questions about how to successfully use this substance in your soils. Biochar advocate David Yarrow is working to provide answers to sustainable farmers and gardeners across the country through a Sustainable Agriculture Research and Education (SARE) project already underway in Kansas.

The Growing with Biochar initiative will assist growers to use, properly prepare and test charcoal (biochar) in soils on at least 28 test beds in the Lawrence, Kansas foodshed with the ultimate goal of creating an instruction manual on how to produce and use biochar on the farm.

“Lots of scientists are doing serious research into biochar. That’s not what we’re trying to do,” said Yarrow. “We’re trying to make this method accessible and understandable to growers.”

In addition to various instruction manuals and reports, the project also aims to provide field days, grower training, open houses, and other public events.

Yarrow started making biochar from a brushpile at Four Oaks Farm in Topeka last winter with “an old, beat-up 55-gallon drum and some stovepipe to make a burner.” Yarrow did 25 burns that winter, and traded a load of wood chips with permaculture teacher Steve Moring for finished charcoal. Moring charged the biochar with SEA-90 sea minerals and applied it to one of his garden plots. The positive effects of the biochar on Moring’s plants served as an inspiration for the initiative.

“I met David early last year when he was working near Topeka producing biochar,” Moring said. “I was interested to see what effect it might have, so I put about 20 gallons of Yarrow's screened charcoal into one of my beds. I had a control bed I didn’t put it in, and I grew vegetables. Vegetables grown with biochar did so much better, so I was impressed.”

Chimney Base with Air Intakes
sheet metal sleeve slides up

Moring’s Vajra Farm is one of the sites participating in the Growing with Biochar project, which includes a diverse mix of farm and garden plots spread throughout Douglas, Jefferson and Leavenworth counties. All the sites are growing organically, but not all are certified organic.

“They are local farms that have an interest in using biochar. It’s an assortment of operations. There are vegetable farms, fruit and nut farms, and an herb farm. One farm has a 35-acre wheat field that they will try to do something with,” said Yarrow. “It will be tricky, because each farm—being a different kind of farm—is going to have to develop specific and different methods for how they use the char.”

Yarrow applied for a Sustainable Agriculture Research and Education (SARE) one-year, farmer-rancher grant to help fund the project, which was approved in March. This spring, soil samples will be taken and biochar will be spread on the test plots.

Each participating farmer must define at least one specific research issue and design a field test setup and protocol to explore the issue. Each farm has a minimum requirement of three test beds. One bed will serve as a control with fertilizer only. The second will get regular fertilizer plus biochar. The third another will receive fertilizer and biochar, plus sea minerals, and compost. Growers will have test plots set up to provide a visual demonstration that allows for photo documentation, field days and training sessions.

Masonry Base Holds Barrel
spacing allows air flow underneath

“We have several farmers on board, and one with fruit trees. I’ve been making the biochar for him,” Moring said. “when he plants the trees, he will put some biochar right in the planting holes, and out about three to six feet around the tree in the top four to five inches of soil.”

Yarrow has been teaching the participants how to make their own char. In February, he made cedar tree biochar. “Juniperus virginiana is a pernicious pest in prairies and pastures, so we’ll test it as char feedstock and soil amendment. Its rich resins and oils make an attractive biofuel feedstock, and perhaps a microbial stimulant.”

He says he has observed ”a wildfire of interest spreading about biochar among growers” in the last several years. “In most situations, farmers have heard of it, but don’t have a clue how to start using it on their own farm,” he said. The pivotal point, for Yarrow, is that growers learn how to take raw charcoal and apply it to soil so that a relatively small amount of charcoal provides maximum results.

Air Intakes in Barrel Bottom
1-inch holes for under-air

“I’m trying to demonstrate how to prepare the charcoal for use in soil so you get optimum response, and then we want to document this and start teaching this method to farmers,” Yarrow said. “When the USDA did their study of this, they put 20 tons of raw charcoal onto farmland, and to me, that’s really stupid, because we know from what we’ve learned in the Amazon that it will take two years for that charcoal to become fully effective in soil. We know there are specific steps you can take this raw charcoal through and prepare it so that when you put in soil instead of putting 10 or 20 tons per acre, you can put just a few hundred pounds per acre and get a 50 percent growth increase on your plants. We’re not just dumping charcoal in soil, we are demonstrating a method to prepare it for optimum use in soil.”

Adding raw or unprepared biochar to some soils can inhibit crop growth for the first year, potentially leaving growers who do not understand and follow proper practices to prepare biochar disappointed with initial results.

Micropores in Biochar
micro-sponge is huge internal surface area

A September 2012 International Biochar Initiative study revealed that participants ranked “the lack of sustainability monitoring, reporting and verification methodologies” among the greatest potential risks from biochar.

Besides lack of guidance, another barrier keeping biochar out of the mainstream soil amendment spotlight is an absence in the marketplace. Because there is no biochar industry making large amounts of char, farmers haven’t been able to purchase it commercially to use it on their farms, but that may be changing.

“In the last 12 months, there have been maybe a dozen or so new companies that announced they have equipment to produce char. They are looking for farmers to buy their biochar and start using it,” Yarrow said. "Unfortunately, most framers know very little about biochar, and don't understand how it can benefit their soils, crops and profitability."

Yarrow has been in touch with solid waste officials in Kansas City about acres of wood chips that currently sit rotting unused into CO2, methane and mulch. This biomass resource may eventually be a pilot project to produce biofuels as well as biochar. He envisions teaming up with a composting, landscaping or arborist business, or the City of Lawrence recycling facility to eventually expand biochar production in Kansas cities.

“We’re hoping next year that we will have a lot more farmers that will want more charcoal on their land, so this pilot program will be able to crank out s larger quantity of char than we can do right now and get it spread on more farmland for the 2014 growing season.”

Venturi Air Intakes
slanted slots in chimney adapter


Always looking to innovate, Yarrow said he recently designed a new chimney adapter for a burner to create a venturi and utilize a vortex. “We have a little attachment that takes that takes a 6-inch hole and connects it to an 8-inch stovepipe, and then we put diagonal slots in the fluted, beveled part of the attachment,” he said. “The result of that is that now we have a little vortex inside the chimney. We have the gases, instead of shooting straight up the chimney, spinning in a vortex. It provides for more complete and rapid mixing of the air and the gases, so we get more rapid and intense combustion of the gas.”

The next step, said Yarrow, is to create a secondary combustion chamber to contain the gas flare, and "start using it to do useful things like heat water, cook a pizza, or melt metal.  Whatever we can design, we're going to start planning to use this burner as a useful heat source."


According to the International Biochar Initiative, biochar creates a soil carbon pool that is carbon-negative. It is this carbon-negative aspect of biochar that Yarrow wants to put front and center. In fact, he wants to put a “cool-food” label directly onto food produced using carbon-smart farming methods to alert consumers.

At the end of the summer Yarrow plans to take stock of the Growing with Biochar project and try to arrange for the crops grown with biochar to be harvested separately, specially labeled and sold locally at the Lawrence food co-op and area farmers’ markets.

“It’s going to be a first foot in the water as a test of this "cool-food" label concept,” Yarrow said. “If it proves to be successful, we will proceed to the next step, which is to expand our land in production next year and to develop a full-scale labeling and initial certification or licensing to give growers permission to use this “cool-food” label. We will have a lot to do to develop this label and the technical specification to define what “cool-food” is and create some publication, education and marketing tools to make consumers aware of what this new food label and product is.”


Vajra Farm

International Biochar Initiative
SARE grant with 8 Kansas farms
SARE Biochar proposal
Growing with Biochar
Biochar on the Farm
KAW Valley Biochar

Biochar in Soil
The 4 M's to Prepare Biochar
Using Biochar in Soil
World Class Soils

Carbon-Smart Farming
Let Freedom Ring!

"Cool-Food" Labeling

TLUD Fabrication & Operation

Woodgas Power & Biofuels
Woodgas Wizard Wayne Keith
Woodgas History

Nutrient-Dense Food
Nutrient-Dense Introduction
Nutrient-Dense Campaign
Nutrient-Dense at SaratogaApple

Sea Minerals
Sea Energy in Agriculture
Nutrient-Dense Milk
SeaAgri: SEA-90 distributor


the story
the source
the miracle
the promise
Research & Demonstration
Biochar Test Plots
Vajra Farm
Hoyland Farm
Lulu's Garden
Common Ground
Moon on the Meadow
Buller Family Farm
Give Growers Guidance
on the Farm
SARE-funded project

Lawrence, Kansas

Let Freedom Ring!
Geology into Biology

Carbon, Minerals & Microbes
Venturi Vortex
TLUD Biochar Burner

optimum combustion
Lettuce Seedling
Trials with Biochars

Saratoga Apple, Summer 2010
The 4 M's
Prepare Biochar
for use in soil


grow food in changing climate
Eating Our Way
to a Sustainable Future

answers to climate calamity
Nutrient Dense
at Saratoga Apple
Divine Ratio
Alice in mathematical wonderland
Water Angel
in India

KAW Valley Biochar     Growing with Biochar: a USDA SARE grant project     6/21/2013