Author Topic: Biochar  (Read 2564 times)

agroventuresperu

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Biochar
« on: October 02, 2025, 06:31:13 PM »
Does anyone here make there own biochar? If so, what is your recipe?

growinginphoenix

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Re: Biochar
« Reply #1 on: October 02, 2025, 06:33:13 PM »
I made it for a while out of coffee grounds so I didn't have to grind it up after.

Tropicaltoba

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Re: Biochar
« Reply #2 on: October 02, 2025, 08:07:12 PM »
Not really a recipe but I would often suffocate my fire pit to put it out which would make a lot of charcoal. I then used the acidic leachate from my bokashi fruit and veg peel waste to both activate the charcoal and neutralize the wood ash. The liquid would then be ph neutral and I would add it to fruit trees and very potassium rich. The charcoal would then be added to my pots instead of perilite/fir bark.

After a deep dive into the whole process I did become a little concerned about polyaromatic hydrocarbons (PAH’s). It seems that depending on the oxygen and temperature nasty byproducts could be produced. Now some PAH’s are formed in nature from wood decomposition and may be benign, but others can be nasty.

These may not be a big issue in the ground, but I do my stuff in pots in gh, and I think I could potential be an exposure problem.


Fruit Jungle

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Re: Biochar
« Reply #3 on: October 02, 2025, 08:40:14 PM »
I have a giant kon tiki, quench with sea-90 and potassium sulfate solution, both are cheap. I don't worry about inoculating with biology, your soil will do that after incorporation.

Coconut Cream

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Re: Biochar
« Reply #4 on: October 02, 2025, 11:01:01 PM »
Nope, way too much work.
USDA Zone 10A - St. Lucie County, Florida, USA - On the banks of the St. Lucie River

endemic2earth

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Re: Biochar
« Reply #5 on: October 03, 2025, 01:16:34 AM »
Does anyone here make there own biochar? If so, what is your recipe?

Lots of people out there thinking theyʻre making biochar & really just making charcoal, which could have a negative effect on your soil or potting mix. So important to follow a scientifically-validated recipe. I recommend the university agriculture program of your choice, is there a good one in Peru?

Fruit Jungle

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Re: Biochar
« Reply #6 on: October 03, 2025, 09:53:04 AM »
People make it way too complicated. Terrapreta soils have lasted for centuries and they didn't follow any modern scientific theory. Based on what I've read certain feedstocks just last longer than others (hardwoods longer than manures), and low O2 also makes char that lasts longer, but even the worst made chars have a recalcitrant fraction that will last a very long time. The only char that has ever been detrimental to my soil has been uncharged char.

Finca La Isla

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Re: Biochar
« Reply #7 on: October 03, 2025, 07:33:20 PM »
We make char in a T-LUD adapted steel drum. The char is produced at about 850c which burns off the volatiles.
By using this method no smoke is produced and the resulting char is much more porous.
Peter

BP

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Re: Biochar
« Reply #8 on: October 03, 2025, 09:05:47 PM »
Does anyone here make there own biochar? If so, what is your recipe?

Lots of people out there thinking theyʻre making biochar & really just making charcoal, which could have a negative effect on your soil or potting mix. So important to follow a scientifically-validated recipe. I recommend the university agriculture program of your choice, is there a good one in Peru?

I never really thought about it more than thinking it would be something like making a fire in a hole with a bunch of hardwood branches and then covering it with dirt. Is that just charcoal? Never tried it out

tongmuan

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Re: Biochar
« Reply #9 on: October 04, 2025, 10:22:44 AM »
We've been making biochar from bamboo using what I guess is called a retort kiln, bought on Facebook from somebody who makes them. Basically it's an insulated barrel on top of a fire, with a chimney going through the barrel in the middle, and a smaller metal pipe going down from upper part of the barrel to the fire area for gases released during pyrolysis.

The next day, we crush the generated char and add a lot of worm compost or organic fertilizer, and keep the pile covered and moist with a mix of water, EM and molasses for at least two weeks before use. Not sure if this makes sense, but that's our process currently :)

Would also be interesting to know how others use biochar when planting fruit trees in the ground. Mix in the planting hole or spread on top of the soil or both? And what kind of amounts?

Seanny

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Re: Biochar
« Reply #10 on: October 04, 2025, 06:13:32 PM »
Producing biochar involves high temperature and long during of heating.
It is very energy intensive.

Finca La Isla

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Re: Biochar
« Reply #11 on: October 04, 2025, 07:26:18 PM »
Not sure what you mean by energy intensive. The wood burns and converts into biochar, there’s no outside energy used.

Finca La Isla

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Re: Biochar
« Reply #12 on: October 04, 2025, 07:33:20 PM »
From fallen trees and prunings we mulch with small sticks and leaves as well as large branch pieces. Mid size sticks are cut and stacked like cordwood to dry. We fill our barrel and produce the char. Depending on wood density it might take 2 hours to produce the 10kg or so that we get per batch.
Ideally we soak EM into the char and then apply it. But we also simply apply topically and spray microorganisms every two weeks on our char and mulch mix under the trees.
Peter