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Easy Biochar Inoculation - does this make sense?

For our in-town small garden plot, we make something that is basically mimicking biochar. My question is, does it make sense to do what we’re doing?

We get naturally made charcoal in bulk that they make locally in huge bags (about 200 pounds), then break up the big pieces into tiny <1cm pieces. (Most people buy the charcoal to grill out or cook with, as it’s not technically biochar)

We mix in a 5 gallon bucket about 2/3 tiny charcoal pieces and about 1/3 guano de isla (basically a bird-feces organic fertilizer sold locally, made in Peru where we work, but it’s so popular that it’s sold internationally. The birds live on an island, so their diet is just fish, so their feces is super rich). Then we fill up the bucket with liquid gold (urine) and let it inoculate for at least a couple weeks. I could substitute our duck poop when we run out of the guano de isla.

So basically charcoal saturated with urine and poop. As I understand it, biochar is burned longer than charcoal, so the oils are all burnt out leaving more gaps to be filled with beneficial bacteria. That being said, what percentage of benefit am I getting with just using charcoal in this manner instead of going to the effort of making biochar? 25? 50%? 75%?

I’m just gauging if it’s worth it to make biochar for in-town use. Of course a big part of my plan is activating or inoculating the charcoal with super rich fertilizers.

Current use of this biochar impostor is placing under a layer of compost in intensely planted polyculture garden, placing it at intervals in our compost to speed up the composting. I think I might put it under plantings on new trees also.

Any thoughts on our process? Pros, Cons, comparisons with true biochar?

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Low temperature/oily charcoal can be toxic to soil organisms and plants.


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I’ll check out the article at some point, Robert. But off hand, how do you tell if a charcoal is “oily”? I have made barrel charcoal, and I have a colleague here in Costa Rica who showed me the results of an even simpler system for making charcoal, using something like a 5 gallon empty oil can. Assuming (good assumption) that we aren’t going to take the temperature of whatever charcoal we eventually make, how do we know if it was “low” or “high”, “oily” or “not oily”?

I attempted to start a thread about biochar, and your observation is an excellent example of the kind of experience I was hoping to learn about. Thank you! And…I’m sorry I have no good answer to your question. One mini-thought that comes to mind is based on what Robert Fairchild observes below, that low temperature, oily charcoal can be toxic to plants. My thought/questions is, What have you found in terms of the advantages or dangers of the system that you are using? And also, Have you ever done a side by side test, with one plant receiving and the next one not receiving your “fake” biochar?

The easiest test is to crush some with your hands. If it washes off with just water it’s not oily. If you need soap to wash it off your hands, it’s oily.

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