Biochar: building a foundation of carbon

With all these solutions, where do we begin? Biochar. This foundational time tested technique is essential to have in the old quiver of regenerative soil building techniques. It creates topsoil that grows nutrient dense food, sequesters carbon from the atmosphere and keeps it in the soil where it belongs, and it makes for a great conversation around any fire.

Build a fire that you would feel comfortable burning the remains of a Viking Warrior on. Construct it tight, and uniform, like a pyramid with the top lopped off, like the picture on the back of a one dollar bill.

Light it from the top. This way it draws more air and burns hotter to burn out resins and saps. It should sound like a jet engine due to the amount of air moving into the flame and it should be smokeless. Top Lit Up Draft (TLUD) is what we are aiming for. Once all the wood is glowing, put it out completely with water.

Pyrolysis is what we are shooting for. This video should explain pyrolysis. Mostly…

The goal: Burn the gasses that are in wood and retain 50% of the carbon. Store that carbon in soil. With an incredibly high surface area biochar works like a coral reef for soil life. One of the worlds leading ecological designers, Geoff Lawton stated that charcoal is “a high density housing commission for soil bacteria… one Tablespoon of dissolved charcoal can have the surface area of ten acres.”

If your interested in efficiency then look into a biochar kiln or two. The design options for these are endless and can be built out of recycled materials. Mostly…

Here is a friend hard a work on the Adam’s Retort recently constructed at the Tierra Learning Center.




A lot of trial and error. Once it is in the soil, spray it with a heathy dose of compost tea, biofertilizer, bokashi, or just pee on it. Urine is high in nitrogen and will provide the necessary starter for billions of amoebas, fungi, protozoa, and nematodes.

If you build it they will come, right? And they did in the Terra Preta soils of the Amazon, where the richest soils on earth have been found to exist due to human cultures burning and burying charcoal in this manner. High heat, 1100 degrees Fahrenheit. Hot! Turns out we humans can do some pretty beneficial activities to enhance the environments that support us.

More carbon in soils = more water in soil = increased life in soil = more nutrient availability in soils for plants to access = more nutrient dense plants = healthier happier people burning fires and growing food.

Is there such a thing as good Biochar and poor?  Yes. Here are two simple tests past on by Peter Hirst from New England Biochar shared on a spectacular day walking the sandy ridges of the Chumstick Valley behind Tierra Learning Center in Leavenworth, Washington.

       Rinse Test – If you can rub the charcoal on your hands and wash it off with water, then you have good Biochar. If you need soap and water to clean it off your hands, then it did not burn hot enough and there is still to much sap and resin in the wood. Learn something and try again.

       Worm Test -  Mix your finished charcoal with compost. A ratio of 50% Compost : 50% Biochar. Place that mixture next to 100% Compost and pile a handful of worms in the middle of the two mixes. If the worms head into 50:50 Biochar Land then you have a green light. Go! Mix it into the soil and your ready to plant. Biochar is the perfect replacement for perlite in potting soils.


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