On the topic of biochar

Hi folks,

As a newbie to so many aspects of homesteading, my interest of late has turned to biochar. Is there a resource that folks would consider comprehensive on the topic? I wish to avoid a slew of questions, though two arise just now:

1) Is there a best time in which to amend soil with [activated] biochar? (I am in north-central Maine).
2) Is the biochar produced in a burner of some sort, where the wood source does not actual combust and gasses are vented, not vastly superior to biochar produced in a burning pit? It seems that with the latter one is also producing a quantity of ash--useful in some ways, but not equivalent to biochar?

Thanks!

craig

Hi Craig-

I don't think there is a preferred time of year to apply biochar to a soil. As far as making your own biochar, making your own retort burner may be more efficient than a pit method, the key being to burn it in a low/no oxygen environment. Yes, ash is not the same as biochar, but does have its own uses.

For resources, there are a few books out there. The Biochar Solution by Albert Bates, The Biochar Revolution: Transforming Agriculture & Environment by Paul Taylor and Hugh McLaughlin. I also found Biochar for Home Gardeners: A Guide to Producing, Charging, and Applying Biochar to Dramatically Improve Soil and Plant Health by Jeff Fry and this is a free kindle download for anyone that has one of those things, but costs just a couple dollars for a paper copy. Its about 60 pages and appears to be more of a pamphlet than a book but it sounds like it contains the necessary information to guide people in the right direction to producing their own. Good luck!!

I love the idea of fertilizing soil with biochar, but I'll have to wait until I can buy my own farmland! I've read a lot about all the amazing benefits but just can't reap it for the moment.

You can add bio-char anytime of the year. If I had to pick a particular time, it would be in the fall:
1)The bio-char get to leach just a bit more oil from it's pores
2)It get to "steal/absorb" minerals from the soil until it reached an equilibrium without affecting growing plants.
3)It is still warm enough for the microbes to cross-colonized the bio-char and also the soil.
4)It gets to absorb water/snow melt
5)It is worked deeper into the soil over the winter, and less worry about biochar dust or drying out.

Biochar(vented sungas) is different from charcoal kiln. Charcoal is made at a lower temperate so it pore of the charcoal is filled with oil/tar that actually suppress plant growths for years, eventually it will leach out but it will take a really long time. It also releases unburnt hydocarbon into the atmosphere. From what I have read bio-char made at 450F is the best, lower temp and it contains too many oils and higher temps and the yeild goes down and the pH of the cio-char gets to high

Great stuff. Now, my homework:

* why is the "leaching" of oil from biochar a desirable;
* what is the biochemical process that comprises the argument for the addition of biochar;

Need to get to my reading!

Thanks again,

Craig

Think of the "natural preservative" that we historically soaked rail way ties/lumber in. The oil that is in biochar can be vaguely similar, and so it can suppress plant life. Of course given time fungi will break it down.
Also if the pores of the biochar is filled with lets say regular cooking oil, said oil will not let water and the minerals that are dissolved in the water to enter the pores and be trapped, for later use by plant/fungi 'roots'


Why is biochar good:
1)instead of the dissolved minerals leaching out of the soil the bio-char/activated charcoal loosely hold onto it until the plants need it.
1b)with the plants having absorbing water with higher amount of mineral it will overall need less water to get all it's required dissolved minerals
1c)with all the fungi "roots" growing in the biochar, plants can just trade sugar with fungi for minerals instead of wasting time using ineffective+wasteful plant roots
2)The pores of the biochar will house alot of microbes that are all pooping/peeing (manure) and decaying so more bio-available mineral that is readily available
3)The pores of the biochar houses "good" microbes
4)The pores of the biochar holds water like "sponge" so less frequent watering
5)Regular biomass will capture carbon for 6month -300yrs until it dies and then it rots and turn into CO2 in a a season or two, at most 7yrs. But biochar will not rot for thousands, maybe millions of year. so less greenhouse gas.

I've watched a dozen or more Youtube videos on people's various retorts that they use to create biochar.  They work --- most of the wood remains, while the nasty gasses are burned off and charred pieces of wood is left.

My logic leads me to believe that just burning the wood in a conventional fire pit, and then shoveling out the coals and the logs break down would lead to a purer lump of charcoal.  Without a retort, the wood would burn hotter and that would lead to a more porous chunk of charcoal, yes?  The hotter temperatures (upwards of 2000 or 2100 degrees F) would more quickly cause the wood to gas off any nasty chemicals.  While there would probably be more net loss of biomass, the charcoal that remains would be qualitatively better.

I've never built a retort: I just use my fire pit and then I use a shovel to scoop out the coals as the logs disintegrate.  It allows me to burn BIG hunks of wood (like tree-trunk rounds).  I scoop out the coals and dump them into a water-filled bucket.  

Regarding making biochar: I really enjoyed the Living Web videos and learned so much.
Here's their playlist (six videos totaling around 4 hours):

Marco Banks wrote:I've watched a dozen or more Youtube videos on people's various retorts that they use to create biochar.  They work --- most of the wood remains, while the nasty gasses are burned off and charred pieces of wood is left.

My logic leads me to believe that just burning the wood in a conventional fire pit, and then shoveling out the coals and the logs break down would lead to a purer lump of charcoal.  Without a retort, the wood would burn hotter and that would lead to a more porous chunk of charcoal, yes?  The hotter temperatures (upwards of 2000 or 2100 degrees F) would more quickly cause the wood to gas off any nasty chemicals.  While there would probably be more net loss of biomass, the charcoal that remains would be qualitatively better.

I've never built a retort: I just use my fire pit and then I use a shovel to scoop out the coals as the logs disintegrate.  It allows me to burn BIG hunks of wood (like tree-trunk rounds).  I scoop out the coals and dump them into a water-filled bucket.  

The Retort is probably the most efficient method with a TLUD being a close second, the reason is there is more complete combustion, which does sound contrary to logic.
However we have to think about what happens during combustion and how a forge works since this is how the retort and TLUD work, jets of O2 in small quantities.
Rather than a blower or bellows forcing air into the hot spot like you do in a forge, the two "ovens" work a bit differently and that's because a forge usually starts out with charcoal (wood fired forge) and it is the charcoal we want to make.
So, we start with dried also known as seasoned wood, this is for ease of burning and less impurities to get rid of.
We stack this wood in, leaving as little space as possible then we start the fire for a top down burn, the reason for that is to get the air flowing through our six or seven 1/8" holes in the bottom of the furnace and the heat moves that air up to the stack (chimney).
This creates a hot spot fire that vaporizes the combustibles contained in the resins (dried out sap) and all the other unwanted things that make up the wood, what we are really trying to do is leave the lignin (cell walls) and remove everything else.

It isn't that a pit fire won't work, that is how the ancients did it, but it takes a lot  more work to get that "charcoal" to the point of burnout that it will sound like glass breaking when it is snapped in the fingers. (this is a good test to determine if you have pure enough charcoal)
In bio char we are wanting some carbon with lots of spaces that are empty voids because that is where our microorganisms will set up house keeping.
This is the reason for using a retort or TLUD, to get to this point without having to "tend the fire" the whole time the burn is going on.

Large hunks are not going to experience as complete a combustion as smaller pieces will simply because of the mass. Plus you then will have to break up that huge hunk of charcoal so you can inoculate it with your microbes.
In less you incorporate a bellows or some other air injector setup you will not reach the temperatures needed (2200 to 2600 f) to get that nice breaking glass sound when you snap your charcoal in your hands.

Once you have the charcoal, you now need to get the microorganisms growing and living in it so you have choices, make it part of a active compost heap, soak in aerated compost tea, or soak with a compost and mushroom slurry.
The normal level for biochar (as first found) is around 12 inches below the surface, but we do not know if that was by design or if it was the result of sedimentation.

Redhawk

Redhawk,

When you say...

"The normal level for biochar (as first found) is around 12 inches below the surface, but we do not know if that was by design or if it was the result of sedimentation."

...are you talking about layers of biochar found in historical gardening areas, or something else?

Thanks,

Craig

Biochar was first discovered by Lieutenant Francisco de Orellana who was under orders from Conquistador Gonzalo Pizarro on an expedition into the Amazon Basin, but he didn't know that he had discovered anything important since Conquistadors were all about the gold and silver.

This is from a paper by Emily Wayne
Oxford University  (Queens College)

"Archaeological
surveys have confirmed the correlation
between the situation of the terra preta sites
and the civilizations Orellana described
back in the 16th Century. Furthermore, the
presence of pottery shreds and food and
animal waste in the soils demonstrates that
they are anthropogenic in nature. Through
careful cultivation over many centuries, the
people of the Amazon were able to
compensate for the limitations of their
natural environment, creating a sustainable
agricultural system capable of supporting
possibly millions of inhabitants.

Based on linguistic and ceramic evidence, Donald Lathrap hypothesized in the 1960s
that the confluence of the Amazon, Negro and Madeira River formed the centre of a
vast and advanced civilization spanning from Brazil to the Caribbean. Its rapid decline
has been predominately explained by the Old World diseases brought over by the
Spanish, to which the Amerindians had no immunity.
The rediscovery of this lost civilization is fascinating. Perhaps more surprisingly, so is
terra preta itself: even chemical fertilizers cannot maintain crop yields into a third
consecutive growing season, yet these dark earths have retained their fertility for
centuries. A crop planted on terra preta can produce a yield up to four times greater
than one planted on soil from similar parent material.
Furthermore, as first reported by Wim Sombroek in 1966, the earth seems to increase
in biomass. Local farmers who mine the soil commercially claim that, as long as a
patch of 20 square centimetres is left undisturbed, it can double in size within about 20
years. It is suspected that this phenomenon is caused by a combination of bacterial
and fungal activity, though as yet no firm conclusion has been reached. So what is the
secret behind the soil’s unusually high
fertility?
The key ingredient, it appears, is carbon.
Terra preta soils contain up to 9 per cent
carbon, compared with 0.5 per cent in
surrounding soils. This is the cause of the
earth’s dark black colouring. The charcoal-like
materials found in terra preta are most likely
to originate from fireplaces used for cooking
and firing clay pots: the patches with the
highest carbon concentrations appear to be
those situated by village refuse sites."

There is work still going on about the best method for using biochar to recreate terra preta.
The particles found in old world sites is finely chopped and the biology found in terra preta is vastly superior to what is found in soil where new biochar has been placed, this is the result of time most likely.
It is also possible that new biochar that is inoculated with both bacteria and fungi would perform in the same way true terra preta does.

Redhawk

Fascinating.

Emily has done some great work in the terra preta mystery.

Most of the actual layers of identifiable biochar (which is different from charcoal since charcoal is not biologically active and bio char is active) are located in distinct layers with the lowest being around 12 inches below the surface.
The soil is very interesting since it can actually replicate itself, harvesters have shown that if they leave a piece of the right size alone, that in 20 years they can come back and harvest a whole new crop of terra preta.
This is thought to happen via the bacteria and fungi present in the terra preta.

Redhawk

I am about to launch, in late June, a sort of back to the land transition (me, already past 60 and ready to embark on "the good life"), which will entail preparing new growing beds in a forest/field setting that has not been farmed or settled. I am increasingly keen not only on producing biochar, but on its potential role in the creation of all my growing beds.

I think that its important to state that biochar by itself is not a miracle drug that will immediately fix all that is wrong with infertile soils.  It is one part of a complex whole, all of which brings more and more carbon and biologic life into the soil profile.  Charcoal by itself doesn't bring fertility --- it's basically inert.  Innoculated charcoal becomes biochar, but just by itself really doesn't do that much.  Just adding good biochar will not bring about a sudden and noticeable transformation in your garden beds.  But when integrated with nitrogen fixing cover crops, compost, mulch, animal integration, swales, and a dozen other soil-building strategies, biochar makes its contribution to the health of the whole.  You will not be able to point at just one variable as say, "See -- that's the secret."

And people will ask you, "So, what's your secret?  Why are your apples so good and your carrots so tasty?"

No secret, and one one magic bullet.  As they say on those Saturday morning commercials during cartoons when they are trying to sell you cereal or Pop Tarts: "Biochar is a PART of this healthy breakfast."  

Did I just compare biochar to sugar cereal?  You get what I mean.  It's ONE part.  An important part, but not the end-all-be-all.

The other thing that is important to remember is that improvement of your soil is an ongoing process.  You'll never have enough biochar, in the same way that you'll never have enough compost or wood chips or other biomass.  So the key is to enter into an ongoing process of constantly making compost, constantly mulching, constantly adding bio-char . . . and gradually moving outward from zone 1 to an ever increasing sphere of land . . . zones 2 and 3.  Bio char is one tool that, if applied over the next 30 years to your soil, will make a significant difference.  It becomes the reef onto which other soil life attach (like a marine reef becomes the home for thousands of other species).  This is in concert with fungal networks, root exudates, soil biota and other agents of soil transformation.

Get all excited about biochar!  And add to that an equal excitement about all the other things I listed in the paragraph above.  All.  Now and continually.

All sober advice.

There was one advise to pulverize the charcoal to do that with a car. What we try next is to do this in a dead end street but between two sheets of tarp.

Yikes.

How might one economically cultivate fungi in quantity?

That depends on the types of fungi and what you intend to use them for.
Decomposers are wood eaters, so you need sawdust, wood chips or logs to grow them in quantity.
Soil dwellers just need a good biology in the soil so they have food and friends, these will spread far and wide.
The main thing fungi must have besides food is moisture in the soil or in the wood.

Redhawk

Some one may have said this already and I just missed it - but it is worth knowing...

Bio-char, as has been said, needs to be "inoculated" before you add it to your soil. By itself, it is inert (not a fertilizer). It is used to provide a healthy enviroment / habitat for desirable things to begin happening. "Loading" the bio-char before it goes into the soil prevents it from having to get "loaded" after it is put into the soil.

But, what I didn't read was an important warning: If you add it to the soil without it having been inoculated, don't be surprised if it has a negative affect on your plants for the first year (or 2). What you will have done is "called upon" your soil to provide the inoculation. That means some of the stuff your plants need for good health is going to be getting captured by the bio-char first (the inoculation / loading). And until that process is complete, that "stuff" will not be as available to your plants. You might wonder what happened and why bio-char is making things worse, instead of better.

I like everything I have learned about bio-char. Right now, I'm having trouble finding 35 gallon barrels for the retort chamber. But I'm not giving up.

One of the things I plan on loading into it is the ABUNDANCE of gum balls we have.  I figure that is about as good a use for them as any. That and using them in the bottom of wicking barrels.  Now I am excited about having them!  ;-)

tony elder wrote:

I like everything I have learned about bio-char. Right now, I'm having trouble finding 35 gallon barrels for the retort chamber. But I'm not giving up.

I wouldn't be to concerned about that.  Any barrel that fits into your larger barrel will work.  I originally used a 7 gal oil barrel as the inner chamber.  I just pile wood in the 55 gal barrel to just a bout 6" above the top of the 7 gal barrel.  It worked great, but of course, the batches were much smaller, so less than ideal.  At least you can still make some charcoal while you are searching for a larger barrel.

Thanks for the suggestion Todd.

I was about to start another topic to ask what the best alternative would be.  Those rascals are hard to find. Not sure if I will have any better luck finding a 7 gallon barrel. It seems 55 gallon is about the only metal barrel that is readily available.

I'm thinking - since they are harder to find - and since the smaller chamber is going to be exposed to the greater heat (burn out faster) - that I should be thinking about getting more than one when I do locate a source.

55 gallon drums are common and relatively cheap.

Anyone else with suggestions?

BTW my husband makes biochar simply in a drum by observing and managing the fire. It's a bloke thing I am interested only in the end product. He says it's easy.
The real nice thing about biochar is that it uses all the garden wastes which are not suitable for the compost including thorny blackberry canes all that wooden debris.
For Aussies: do it aoutside the fire season or get permit.

Thanks for the reminder, Tony. You got me thinking again about the ratio one is looking for between the charcoal and the microbacterial inoculant (and no doubt there's a technical term for that I should learn). Still very early in my research on this, but I was thinking of green manure as that source. However, questions remain as to how much charcoal should one use for one ton of manure, along with how much time does the mix need before it is stable to put in the growing soil? Would aged manure in fact be better, as green would require its own time frame to decompose? I have been thinking of having two operations going on: biochar production, and compost production. Do others combine these processes--using charcoal as a compost pile ingredient--and is that efficient?

Thanks all,

Craig

Angelika,

We do like our fire, don't we? Can you clarify about canes and such? If it is all going into the soil, are you saying that the canes and such are better suited after being combined with charcoal et al, or are you saying that it's a good way of burning it?

Thanks,

Craig

Craig Butler wrote:
Thanks for the reminder, Tony. You got me thinking again about the ratio one is looking for between the charcoal and the microbacterial inoculant (and no doubt there's a technical term for that I should learn). Still very early in my research on this, but I was thinking of green manure as that source. However, questions remain as to how much charcoal should one use for one ton of manure, along with how much time does the mix need before it is stable to put in the growing soil? Would aged manure in fact be better, as green would require its own time frame to decompose? I have been thinking of having two operations going on: biochar production, and compost production. Do others combine these processes--using charcoal as a compost pile ingredient--and is that efficient?

Thanks all,

Craig

I know the reason for crushing the char into pieces as small as posible (or practical), is to expose the largest surface area of char as possible to be inoculated so that it can be loaded with the most "stuff" in the least amount of time.

I would assume that to mean - the amount of time it should take for the process to complete would be proportional to surface area that is exposed. And the inverse would also mean that the size (exposed surface area) of the char would determine the amount of elements available for the soil and plant life to use at any one time. I don't think any of that would affect the volume of inoculate the char could hold or need to be completely loaded. Only to say that the larger pieces would probably take longer to load and would be harder or slower to release what had been loaded.

In my mind - I'm thinking the best plan for multiple applications over time would be to start with the finest size possible, and to be less concerned about the size with each new application. Seems that the combination of sizes would make the most resources available over the longest period of time.

Sorry, I can't tell you about ratios of inoculate to char needed to load the char. There may be variables to that ratio based on the quality of the char, and it would certainly depend on the quality or type of inoculate you would be using, as well as the process for loading. I'm sure there are general rules of thumb for that sort of thing, but I don't recall hearing or reading what that might be.

I do recall that saturation with compost or manure teas were usually the quickest medium for inoculation. Nevertheless, I plan to add it with fresh horse manure, leaf mulch, and other green material in a compost pile. I don't intend to do much more than turn it, keep it damp, and allow it decompose. I haven't seen or read anything that would cause me to believe it will not be loaded and ready for application when the compost is ready for use.

In my way of thinking - it will not be "robbing" the manure or compost pile of anything beneficial. The char will not be consuming anything. If anything, it will more likely be a transfer or movement of elements from one place to another. Without char present, most of the elements and water would be subject to leaching and more likely to be lost or consumed. With the char present all the beneficials would more likely move to the available habitat / enviroment which would be more conducive to healthy growth and less likely to be lost or consumed.

Hopefully, someone here will fill in the gaps I'm leaving.

Quick question to all,

Is there no other advantage to using dry wood in the pit (or retort) other than the fact that it takes longer to expel moisture? Creating biochar in the work stream of clearing land, as I see in this Edible Acres video Edible Acres biochar, seems a good idea.

Thanks!

Craig

I am reading this compost publication of the 30th which is published in another thread and she back then (!) said that charcoal is very good for the compost. The funny and interesting thing is that she explained how to make charcoal in 3 or so sentences and told that it is very easy. Well back then everyone knew how to manage fire.

Wish I were closer and could visit, Angelika. I like your webpage. Got many friends from Oz, and I'm not that far away! (Hong Kong, temporarily).

On the question of medicinal herbs (which rightly ought to be in another thread), I thought I'd ask you about which medicinals you have been most successful with growing and selling. I have an amateur interest in Chinese medicine (and read and teach Chinese professionally), and with a move back to Maine in June am interested in growing for personal interest and perhaps small-scale selling. I am happy to shift this conversation to another thread or venue if most appropriate.

Craig

Found this Biochar Retort Kiln build instructions.  Looks easy enough.  Maybe a next project.  

Thanks for that, Dennis. The more plans I have, the more learning.

Craig

Enjoyed following the links...  new ideas are never bad ideas.  Thanks.

Craig Butler wrote:
Quick question to all,

Is there no other advantage to using dry wood in the pit (or retort) other than the fact that it takes longer to expel moisture? Creating biochar in the work stream of clearing land, as I see in this Edible Acres video Edible Acres biochar, seems a good idea.

Thanks!

Craig

Green wood has quite afew different types of moisture going on; sap full of sugars, water being just two forms of wood moisture. It will just take a longer kiln time to produce charcoal for making biochar is the only difference.

Redhawk

Thanks for that, RedHawk.

As someone who is not capable of affording or building a metal retort, I am loving the pit method. It may not be perfect, but I have some biochar instead of nothing, and over time any imperfections will balance out as seen in old sites.
 I save all prunings until the fall, nothing larger than 3 inches diameter, and burn it by feeding it to the fire in increments, not allowing the flames to die down. When all is burned I quench it thoroughly with water, so not too much ash, and hopefully the water wash will help lower the higher ph.
 I mix it with the chicken bedding and then mulch with that. Not the best method for incorporating it, but it eventually gets there. I think the most valuable aspect of it is not a fast bump, I have good fertility already, but down the road I hope to be able maintain high levels with less amendments. What could be better than creating long term fertility based on microbial activity? And that isn't even touching the carbon sequestration part.

Good on ya, W. As with so many things in life, there are many paths to reaching the target, but it all starts with using the resources you have, engaging the mind, and working out a way to bring them together.

I would imagine that the original creators of Terra Preta didn't have retorts or TLUD's, nothing wrong ever with doing things with what you have available.
I use what ever left over charcoal there is from my smoker, the fire pit (when we use it) and if I have enough wood to fill my furnace, I set it to going.  
All this goes into a heap then I blend it in with a new compost heap and there it sits until I am in need of the finished compost.
I think this would be how they originally made Terra Preta, so it is bound to be good enough.
We know what was found in those areas was basically trash heaps that would have been burned, so how ever you get it, it should be good.

Redhawk