Terra Preta

[Alan]

LOL.....without knowing about that reccomendation Raymondo, I did that with several bucketts of charcoal this winter!

[canadamike]

Blue, just to get even, one day I'll visit you, and while you are having me tour the garden, when you are proudly contemplating your bed of tomatoes and describing it, I'll silently piss on your shoes

[woodchuck]

Feb 27, 2009 5:19:21 GMT -5 raymondo said:

An Australian academic who is writing a book on the subject of biochar recommends just peeing on it and letting the urine soak in as an easy home method of activating it.

LOL

Interesting idea.

I'll put some 'char under my rabbits and let the urine activate it. ;D

<Woodchuck>

[grunt]

Bunkie: Your DVD hit the mail today. Sorry it took so long, but with all of the extra space on the DVD, I had to go through my hard drive to try and find things to throw in. There's a text file in the Firefox folder in the Applications folder that should explain what's what. You ended up getting about 3.5 Gb of "material".
Cheers

[bunkie]

wow! that was fast! just got it in the mail. will check it out this afternoon. thanks so much!

[grunt]

Finally got around to reading the wikipedia entry for terapreta, and should have done it a lot sooner.
Several points clarified, but two that have been touched on here a couple of times in particular.
en.wikipedia.org/wiki/Terra_preta#cite_note-bechtold-01-9
This goes back to page two of this thread

The chemical structure of charcoal in Terra preta soils is characterized with poly-condensed aromatic groups, providing prolonged biological and chemical stability that sustains the fight against microbial degradation; it also provides, after partial oxydation, the highest nutrient retention[3][21]. Wood charcoal (but not that from grasses or high cellulose made at low temperature), thus has an internal layer of biological oil condensates that the bacteria consume, and that is similar to cellulose in its effects on microbial growth (Christoph Steiner, EACU 2004). Charring at high temperature loses that layer and brings little increase in the soil fertility[6]. Glaser et al. (1998[19] and 2003[25]) and Brodowski et al. (2005[26]) have proved that the formation of condensed aromatic structures depends on the manufacture of charcoal. It is the slow oxidation of charcoal that creates carboxylic groups; these increase the cations' exchange capacity in the soil[27][28]. Lehmann et al have studied the nucleus of black carbon particles produced by the biomass. They have found it highly aromatic even after thousands of years in the soil and presenting spectral characteristics of fresh charcoal. Around that nucleus and on the surface of the black carbon particles, there were higher proportions of forms of carboxylic and phenolic Cs spatially and structurally distinct from the particle's nucleus. Analysis of the groups of molecules provides evidences both for the oxydation of the black carbon particle itself, as well as for the adsorption of non-black carbon[29].



This charcoal is thus decisive for the sustainability aspect of Terra preta soils[30][27]. Amendements of Ferrasol with wood charcoal greatly increases vegetal productivity[9]. Note that agricultural lands have lost in average 50% of their carbon due to the practice of intensive cultivation and other degradations of human origin[6].

It is important to note that the fresh charcoal must first be “charged” before it can function as a biotope[31]. Several experiments demonstrate that uncharged charcoal can bring a provisional depletion of available nutrients when first put into the soil - until its pores fill up with nutrients. This is overcome by soaking the charcoal for a few weeks (2 to 4 weeks) in any liquid nutrient (urine, plant tea. ...).

I have emphasized the two points that have been discussed here. Michel and I had wondered about the unsuitability of corn residue, which is the first point addressed = not enough aromatics to give full benefit. The second is the "charging" of the biochar. So, start using a chamber mug fellas, or start making a lot of manure/plant/compost teas to saturate the charcoal with.
Actually, I think Alan is on the right track with running his through his worms. I don't have the source at my finger tips (read I don't want to be sidetracked for an hour looking it up), but one reference I saw showed no decrease in worm activity/health until charcoal reached over 50% of soil content.

[canadamike]

Of interest here could be the liquid part of our house compost, which most of the time end up in the sink or , in my case, in my wife's borders when she is not around ;D ;D ;D ( she hates the smell and can't be blame for that, and since she sits in her beds to work them with a kitchen fork....)

But that's only fair game. I do it to her and my white cotton socks (she hates them with a passion) keep disappearing....

I guess we're a well balanced couple

[potagere]

I've read a lot of this stuff, and a lot of it is unintelligible to me because my science knowledge is not so good, so I have a few questions to put to those of you who are better at this than I.
First of all, I need to point out that I have neither the skills, the technology nor the PLACE to start making my own low-temp charcoal.
That said, why could one NOT use briquettes?
Here in France (at least in my region), there actually are no briquettes to be had; barbecue charcoal is mad from real wood ("new" or "used") and seems to be produced with pretty basic technology. Why could I not try to use that?

An additional question, which is entirely peripheral: Alan, can you tell me more about your "wood burning stove with a thermostat damper" that you use in your greenhouse, or direct me to a source that will tell me more. I tried heating the greenhouse with an electric heater last winter, and that was a costly error, so this year it has remained cold. I was thinking maybe a pellet stove, but it sounds as if you have found the answer, so I would very much like to hear more!

[potagere]

Oh, by the way, I think women could pee on the charcoal, too. It's not just a male function!

[grunt]

If you can find barbecue charcoal that is not made into briquettes you could use that. The only potential problem with using briquettes made from wood might be in the material they use as a binder to make them hold their shape. Making charcoal does not have to be a smokey affair, so if you can have a wood or pellet stove to heat your greenhouse, you could make charcoal.
It can be no more complicated than lighting a wood stove.
www.holon.se/folke/carbon/simplechar/simplechar.shtml
If you still think it's not possible for you to do, contact the manufacturer of the briquettes, and find out what they use as a binding agent. If you buy enough to make a difference, it's not going to be cheap, as it is suggested that charcoal levels should be 25% of the soil, so think of covering your beds at least 3" deep in briquettes, and figure out the costs.
As for the unintelligibility of the information, my eyes start to glaze over when I'm reading it too. The details that I don't understand I can usually figure out by the rest of it, and by comparing the different sources. The information they each give sort of overlaps, and if you keep going over them, it starts to make some sort of sense.
The names of the different microbial agents at work, or the volatiles that supply the nutrients to them, and the processes that are a result of them are immaterial. It's what the end result is that counts. We likely can't produce an actual terapreta in our soils (they still haven't managed it in any of their research trials), but what we can produce will still be more than worth while, and may eventually become the real deal for another generation to use, and it will still give us enough of an improvement to justify the effort for our own use.
I used likely deliberately, because we "uneducated" ones haven't been taught what can't or won't work, so we will try it - - - and that may just be what does work. Remember, it is not for nothing that we all re-invent the wheel for our own uses, and come up with variations that have never been seen before.
I could give you an over simplified version of what I understand about terapreta and why and how it works, but I think you know more about the process than you realize. Keep reading the research stuff, google or wikipedia anything you don't understand, and keep going over the stuff that you do. Eventually there will be that "Eureka" moment when enough of it clicks into place that you feel you understand the whats and whys of it.
Sorry about getting so long winded, but I warned you guys when I joined up.
Cheers
Dan

[potagere]

Thanks, Dan.

That really is a great (and simple) method of producing charcoal! I'm in the midst of brussh cutting right now (on my neighbour's property, who simply refuses to exercise any control over the blackberries, elderberries, etc. that grow on his land and invade mine. I could "sue", but just cutting it myself is simpler, plus, I COULD use all the biomass for myself!), so there is a lot of small wood (mostly from the elderberries and wild hazelnuts) that ought to work with this. Do you suppose the stuff all needs to be dry/cured like for firewood, or would mostly green wood also work?

The only problem here would be getting the "barrels". Things that are relatively common (and relatively commonly discarde) in North America are not so easily come by over here. I'll have to look around and see if anything can be found. Obviously, there is little point in using small barrels, or you wouold burn more wood than you would get charcoal!!! Of course, if I have to dry the wood, that gives me a year to look for barrels!

Your reply about the briquettes is about what I was thinking : i.e. maybe there is something in the binding material that would be unhealthy. However, as I also mentioned, all we can buy here is "real" charcoal, anyway, so that might work. If I'm just experimenting in a small space, say one of my 2 metre by 2 metre beds, 3" of charcoal shouldn't be a big cost (of course, that would mean waiting for Summer, when the big bags of charcoal are on sale!).

Now, I am still not clear on the SIGNIFICANT (I mean significant in the current context) between "hi-temp" and "lo-temp" charcoal. Anyone understand that? And is this backyard barrel method making hi or lo?

I'll keep working on the scientific niceties. I'm not nearly so sophisticated about any of this stuff as most of you are, and often feel as if I have entered a domain of "gardening" that is out of my league here!

I'd still like to learn more about Alan's stoves in the greenhouse!

Cheers,
Jim

[michaeljohnson]

I have read most of the details on the above posts on the Terra Preta soils in S.A, but was wondering why in places like Australia and maybe even southern california, where regular large scale bush fires seem to rage every year, surely this will put a lot of natural charcoal into the ground year after year over large areas, together with wood ash etc,-does this not then produce a sort of Terra Preta soil in those areas-if not-why.

[grunt]

Jim: You can do green material, but it takes a lot more fuel to get it out-gassing properly, and ends up not being worth it. I'm not sure if the elderberry will qualify for biochar, as it is pithy interior, and not solid wood, but it can't hurt anything, I suppose. I would pile it all up and let it dry first, then make the charcoal.
With out relocating my reference for quotes, high temperature charring drives out more of the volatiles and mineral content that the microbial life see as nutrients, so they are much slower in "activating" the charcoal, and end up being almost the same as grasses for result.The backyard barrel method is low temperature production.
Here is another backyard method, slightly different from Gunther Holon's : www.puffergas.com/historic/rules/rules.html . A couple of notes on this one. If you save the bottom of the top barrel whole, and leave a two inch (5 cm) around the top of the bottom barrel, you can use the bottom as a top cap on the bottom barrel, and pack mud around the edge to seal it when it comes time to snuff/seal off the fire. Or if you can build a metal or brick shelter to stand your barrel in, and leave air ports around the base, you could do the Gunther method with one barrel. Take out one end of the barrel completely, and cut out the other end leaving a 2 inch rim and use the other cutout to seal the top of the barrel. That way you can top load and seal and do your burn.
As for the scientific knowledge, I never took any chemistry or biology in high school or university. I guess i just have a few too many "what if" genes in my makeup to let that get in the way. And it's so damned much fun to experiment. Even when it doesn't work out, you still learn something.

Michael: Natural fires do put a minor amount of charcoal on the soil, but most of the carbon ends up being lost, as the majority of it gets turned into ash. What's left doesn't get incorporated into the soil because it is on the surface. That is part of the reason. Natural fires usually end up sterilizing the top couple of inches of soil, and destroying a lot of the available humus as well. And the smaller pieces of material (branches, etc) usually end up being totally consumed, with only larger pieces left behind. They have found that pieces of charcoal over 1/2" in diameter are too large to activate properly, so the process never does catch hold.
At least that is what I understand. If anyone sees errors in any of this, please do correct me, as I am working from memory here.
Cheers
Dan

[woodchuck]

Mar 14, 2009 1:17:17 GMT -5 grunt said:

Here is another backyard method, slightly different from Gunther Holon's : www.puffergas.com/historic/rules/rules.html

That's the exact same method as the charcoal chimney that I use, but with the added afterburner.

Because the combustion zone and greater part of the heat is above the material, you're assured low-temperature 'char.

It's by far the easiest way to make 'char.

I'd also argue that it's just as efficient as the indirect method if you consider the total amount of material used in both methods. Especially if you're mindful of technique. I've found that you get a more even, complete, faster and much more efficient 'burn' if the material is stood up vertical and is of roughly the same diameter.

Charcoal Chimney Charcoal......I added some new pics recently.
alanbishop.proboards60.com/index.cgi?board=soilbuilding&action=display&thread=2134

<Woodchuck>

[grunt]

Jim: Woodchuck's method also has the advantage that you can make your own burner very easily with any metal pail you can lay your hands on. Make a ring for the bottom out of one can, putting your draft holes in it, more air supply holes in the container you are doing the burn in, or replace the bottom with a coarse wire grate, and a few holes around the top lip for secondary air emission, and you are in business. When the burn is complete, spray the char with water to cool it, so you don't have to worry about it reigniting, and you're done. Since you are looking at basically using prunings to make your biochar, getting smaller pieces of char is easy.
Dan
Edited to add: Add another short "chimney" section to the top, and you get your secondary burn, and can use it to cook with, ala Gunther.
Dan