Portable kiln can make 200+ gallons of charcoal per session...

I made a video last winter of a system for making biochar that is like the Moxham retort but made of standard roof metal and t-posts. Incredibly replicable, costs nearly nothing, and the first burn made nearly 200 gallons of quality charcoal. I'm linking the video here to share with folks. It's a little bit long, but it goes over the whole process and shows it in action. I'm planning to fire it up again this winter and make some simple modifications to make it more efficient.
Last winter I made around 2000 gallons of biochar with a few home made systems like this. All for next to no money or completely free... youtube.com/user/edibleacres has a bunch more of my biochar stuff if you are interested.

As I've been seeing more Biochar articles and videos, I'm wondering:
1) How much Biochar does one really need?... or
2) How much can one reasonably be able to use?
3) At what ratios do people mix this with other organics, or soil?
4) Are some of the advantage in woodchips, or woody debris burned up in order to have Biochar?
5) What are the advantages over "regular" mulch...

I skip around so much it may be a while before I come back, but I think this would be helpful for the masses. Thanks in advance.

I think those are all good questions, and certainly ones that would have answers based on individual preferences / needs I'd think. I like the idea of making a lot of biochar... My reason is that I have 6 acres of land, most of it wooded with red pine with understory of european buckthorn and japanese honeysuckle. At least it used to be mainly that, I've cleared a ton...
I could rent a chipper and run a dirty, noisy, gas engine to break it down or make biochar with it. I've already woven huge brush walls around the land ( https://www.youtube.com/watch?v=2BlHrqpYnHI covers that discussion more), and so biochar makes sense.

In my first trials with it 3 years ago, the beds I added it to did incredibly well. I've since been making it with abandon and either carefully inoculating and using it in key applications (seed starting, transplanting, nursery beds, etc.) or just throwing it onto future beds in its corse, raw state so that in a few years it will begin its magic.

Unlike woodchips, it doesn't go anywhere. Beds where I've added woodchips 5-7 years ago, it's beautiful soil, but there is no legacy of the chip. Biochar I can still see in the soil years later, and it should be there for hundreds and hundreds more.

So for me, if I have corse, branchy funky stuff that isn't great for firewood and would take forever to break down if just laid up in piles the biochar route makes a ton of sense. I'll gladly take the woodchips from someone else who wants to pay for and own the nasty machine to make it!

Sean Dembrosky wrote: So for me, if I have corse, branchy funky stuff that isn't great for firewood and would take forever to break down if just laid up in piles the biochar route makes a ton of sense. I'll gladly take the woodchips from someone else who wants to pay for and own the nasty machine to make it! :

I have tons of Juniper trimmings and was trying to coarse chop it into mulch. This makes a lot more sense. Thanks for the info

For questions 1 and 2, alot. For use in potting mixes 15%. I've read 50 tons per hectare at 100-500 pounds per cubic yard dry weight. Some of the benefits will be lost in the smoke but saps will be retained also, which are roughly equivalent to molasses, when using hardwoods that is. Because it's basically a carbon shell it can hold alot of nutrients and should be mixed with compost or tea, the more the merrier or else it may take them from the soil for years before benefits will be seen. The char should last for hundreds of years if made from tree stock and will provide a long term home for mychorrizae where bugs can't get to them to eat them.

Sean Dembrosky wrote:

So for me, if I have corse, branchy funky stuff that isn't great for firewood and would take forever to break down if just laid up in piles the biochar route makes a ton of sense.

Have you considered a rocket mass heater instead of your wood stove or fireplace? Forgive me if it seems like I am preaching to the choir, but small sticks, branches, twigs are the exact fuel you want for a RMH... And then you get to save and nurture your wood lot into mature trees suitable for lumber, log house, log barn, etc.

Or, for a different route, consider Hugelkultur, you might want to consider burying some of that brush... possibly under a raised bed in the garden (like if you are building a new bed). You don't need to go 6 feet high, but if you dig a trench for a new bed (think rototiller and excavate kinda trench), dump the brush in the bottom of the trench (possibly hit it with some compost tea to jump start de-comp). Amend removed soil, cover, and plant. It's not going to be enough of a sponge to soak up a ton of water, but when the brush rots, it will be enough of a sponge to buffer between waterings. Large logs are recommended for building traditional Hugelkultur beds (6 feet tall and as long as you like) because there is less surface area and the wood rots slower. Under a raised garden bed, slower rot might not be desired, especially if you follow crop rotation and want the wood to rot quickly, before you plant that bed with a root veggie.

If you really want the char (now) and less hassle, just light the brush pile and douse it when it settles to coals. If you have livestock, and have some old poop clumped bedding straw from cleaning beds, dump that on the coals just before you douse it. The coals will char some of the straw and poop (more char, yeah, but it's a good idea to stand upwind for that last part). Then turn it all into your compost pile and let it compost for a couple weeks until it matures into rich black sweet smelling compost.

I compost all my bio-char anyway. The whole point is that the char is full of tiny nooks and crannies that house all the good microbes... And those good microbes are most abundant in compost.

And Just to dispel a myth I heard or read somewhere, bio-char decomposes just as fast as wood chips in the soil. Go take a walk in and forest a few years after a fire and you won't find any biochar in the soil. It all decomposed. The only time it doesn't decompose is those very rare times when it is covered and sealed by mud (on its way to becoming a fossil).


-Peace, Love, and Hippy Thoughts-

-Paul-

I make and use biochar because I have extra wood around and I like making it.  I haven't tried your method yet, but I will this winter.  I don't enjoy making biochar in the summer  Thanks for posting the video, I really enjoyed it.

In response to the question about amounts, I saw one video where the guy testing it used a pretty small amount (can't remember exactly how much), 25%, and 50% biochar against a control where he didn't use any.  Predictably, some plants did best in each group.  So, how much biochar to use?  No one really knows.  Recently, I'm trying to add 10% or so to each compost pile.

Paul, this isn't a personal attack, so I hope you don't take it that way, but my least favorite answers on the forum are when a person talks about a subject, like biochar, and then someone else posts all the things you can do instead of that.  On this forum, there are hundreds of threads about rocket stoves and hugelbeds.

"...bio-char decomposes just as fast as wood chips in the soil"  This simply isn't true.  If you want to test it in a very simple way, dig two holes, say 5 gal size each.  Fill one with wood chips and the other with charcoal.  Check it in a year or two.  I bring in many, many truckloads of wood chips every year and wood chips break down in year or two at the most.  The charcoal simply doesn't do that, whether you bury it or lay it on the surface.  I posted a new study about it in the other biochar thread, but no one needs a study, they can just test it themselves.