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Post by johno on Nov 24, 2008 20:27:08 GMT -5
That's a lot of homework, Alan! It's gonna' take me a while to catch up.
But speaking without having read all the links, I am trying to understand this:
[Alan] "I do think they are making a mistake by creating "fines" from the charcoal, it will degrade and leach nutrients faster whereas the porous surface area of larger chunks will absorb nutrients, release them slower over time, degrade much slower, and then re-absorb nutrients as they are added to the soil."
In a microscopic point of view, the fines are still enormous (compared to microbes and molecules of nutrients). They will still have lots of surface area - to my way of thinking, the smaller you make them, the more surface area is available, by a large magnitude, assuming the same volume to start with. And they should still last practically forever, still acting as sponges for nutrients and housing for microbes. Can you set me straight on this?
Also I want to point out that soaking the coals in nutrients might (haven't tried it yet) make them much easier to crush. Don't recall where I heard that, but it sounds plausible...
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Post by canadamike on Nov 24, 2008 20:37:27 GMT -5
Johno, that would be especially true if one lets them freeze outside in the winter. Even the porous flagstone here ( not sue of the english name, a form of limestone anyway) chips like crazy. Imagine liquid soaked charcoal going through freeze and thaw cycles... That might be one advantage we have over the amazonizn natives. ;D I'll take anything positive I can put my hands on regarding this winter thing, we are already expecting our first winter storm tomorrow...  |
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Post by canadamike on Nov 24, 2008 21:06:30 GMT -5
;D Johno, your right!! I'll be specially dressed and the mask I usually use in woodworking will be on my face!! I plan on wetting it a bit though, but not so much to clog the chipper. Puting in on a big tarp on the ciment platform by the farm's garage and going over it with a car would help too. And this is something a 15 years old will be thrilled to do!  |
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Post by grunt on Nov 25, 2008 4:33:43 GMT -5
I followed a couple of the links posted above, and sidtracked off of one of them (can't remember which one) and came up with this page on backyard charcoal making = www.clt.astate.edu/elind/charcoalvalentine.htmGoing back through the pages, I found the one the above link comes from, and it has a lot of other links on charcoal making = terrapreta.bioenergylists.org/makingcharcoalI also noted on one of the pages linked to above, that corn is considered either inappropriate or inefficient for charcoal making. Something to play with at least. |
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Post by canadamike on Nov 25, 2008 4:43:32 GMT -5
I also noted that Dan, but I think it was more in terms of efficiency, not possibility, something like dry/wet matter ratiomore than anything else I would suppose. Cellulose is cellulose. If dried properly pre burning, it should be very different. Shit, rice hull can do it....
Wet dung probably behaves very differently from dry dung, that they did use, and which is still used today for fire.
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Post by lavandulagirl on Nov 25, 2008 12:19:30 GMT -5
Basically what I'm going to do is thus: My manure spreader is as wide as the raised beds I will make, thus I spread my worm castings in their required area using the manure spreader, then I set the disc hiller to the width of the bed, hill once, go back over the hill with the manure spreader with castings and then go over once again spreading charcoal by hand, last pass will once again be done with hiller, making a raised bed that is flat on top with sloped sides, easy to irrigate, less erosion, deep compost for deep roots. I will work these beds for 3-5 years, maybe longer, the isles in between will be seeded with a cover crop.
Living now in a high fire risk region, my window for creating my own charcoal outdoors is very small. Most of the year is riddled with burn bans in varying degrees here. Working with a small wood stove too, I think I could perhaps do a small experiment along these lines, though. Were you thinking that you wanted each of us to document our success rates? And over what time frame? The 3-5 years you referenced above? It would be interesting to see what we came up wth regionally. As Michel has mentioned a couple times, the available wood or other cellulose material would differ greatly (I have access mostly to oak and pine), and the natural moisture would be a factor as well, I would think. The level of water that needs to be added by region would also be a factor in micronutrient dispersal, seems to me, at least. Percolation rates will differ vastly. |
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Post by orflo on Nov 25, 2008 12:34:46 GMT -5
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Post by johno on Nov 25, 2008 12:42:51 GMT -5
Lav, this might sound bad, but is it possible you could scavenge natural charcoal after a forest fire? There is an MIT engineer who is working on making life better for the world's poor through low-tech means, Amy Smith. Amongst her innovations is a method of making corn cob briquettes for safer cooking fires (smoke inhalation from indoor cooking fires kills untold millions of children.) Below is a set of instructions for making the briquettes from a successful experiment: kiln characteristics: 23" diameter, 34" tall (standard oil drum) five holes, 4cm diam, punched into bottom in a pentagon; same as in Duke burns, and as recommended by the D-Lab work home-made lid from roofing metal and sticks 6" layer of dry leaves and sticks for kindling to fire kiln layered with corn cobs then a second band of leaves, then corn cobs to the top kiln lit with the barrel propped on bricks and no covering over the barrel observed thick smoke at 8 minutes (see photo) at 23 minutes, still thick yellow smoke from kiln, perhaps more yellow than before at 37 minutes (29 minutes of yellow smoke) the emissions vanish rapidly (the feedstock fire has become oxygenated, we call this point the smoke change), open flames rise from the top of the barrel; the barrel is covered partially with the lid and the yellow smoke immediately returns at 51 minutes with barrel still partially covered, thick smoke still present but not so yellow; concerns voiced over loss of biomass if burn is allowed to continue (one is supposed to wait for another smoke change at this point); ideas raised about using a "chimney" for future burns (a cylindrical gap through the center of the kiln, devoid of feedstock, to encourage airflow), this would hopefully accelerate phase I (the process up to the first smoke change, where most of the feedstock is consumed); though, on second thought, it might not save any feedstock to have a chimney also observed that corn cob coals are falling through the five holes in the kiln's bottom 57 minutes, begin the full seal of the oil drum 75 minutes, complete final seal: drum off of the bricks, base surrounded by mud to be airtight, lid placed on fully, cracks covered with mud to seal; several handfuls of mud fell into the barrel during the sealing process here results: after leaving the barrel for about 12 hours (longer than necessary) we found the burn yielded one wheelbarrow of pyrolized cobs (this is 1/3 to 1/2 the starting volume) <5% were unpyrolized, some lack of pyrolysis through the interior of the cobs (maybe 10% of the cobs) most cobs remain whole small amount of resultant ash [From wiki.duke.edu/display/engineerswithoutborders/Biomass+Charcoal there are discussions of making bio char from other materials here as well...] This might help get some creative juices flowing for ideas on making char out of locally available materials. |
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Post by johno on Nov 25, 2008 12:47:32 GMT -5
Great link, orflo. Very clear instructions - thanks!
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Post by grungy on Nov 25, 2008 13:42:21 GMT -5
Very informative, will have to start looking for steel drums.
Thanks.
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Post by canadamike on Nov 25, 2008 14:11:32 GMT -5
My friend Luke and I where discussing making charcoal out of all the leftover wood of the shop. There are probably a couple of hundred wood cords of slab in the field. We decided on ''too much work for the money'' and planned on using it in the future greenhouse.
What is great about theses exchanges is that it focused me on the way they would be burned now. I sure know I will make less ashes and more charcoal in the greenhouse, and making charcoal will end up being done after all.
One of the great gifts of a place like here is that it brings back to the surface realities that are forgotten or unknown by some of us and put them in a practical perspective. Like most, I suppose, I had read on terra plena, but it was hiden by the tons of info I got from othr things.
And now it pops up, I just have to connect the dots between the available wood, some slightly way to eat the greenhouse and I just found an amazing source of carbon and a nutrient retention system that is unparalleled...
What I find neat, too, is that a lot of nutrients are coming from the rain, some sources say that 70% or the world natural fertilizers come from it, clouds and rain capturing free radicals from atmosphere molecules of gazes split by thunder.
On my hard clay soil, when it rains, a lot of it goes straight to the ditch. With some charcoal in the top inches of it, it will stay home.
Cool, very cool...
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Post by Alan on Nov 25, 2008 19:46:54 GMT -5
This is all theoretical Johno, but yes in essence the porous surface of even charcoal fines is huge compared to chunks of charcoal as I am wanting to try out with, but what I am thinking is that you can get a load more nutrient into the pores (pore depth) of a large chunk that should degrade and release nutrients much slower than those of fines, however fines might be preferable in a very depleted soil in which you aren't going to amend heavily with an organic fertilizer/inoculant to interact with the charcoal and it's slow release properties. Lavandula Girl, you got me thinking about this today and this is what I figured out I think might work better, as posted to my blog and Patricks blog: Basically my new idea is; why bring the worms to the charcoal when you can bring the charcoal to the worms. In other words I will create my charcoal, soak it in a nutrient solution and then apply it to my worm bins in the new and improved worm house I recently blogged about. In this way the charcoal (which will be buried in the 36″ deep bins) will be able to absorb nutrients from the worm castings/compost and will also be inoculated by the beneficial soil microbes. Of course this will be applied in a two layer hill system as described in my original blog and will still entice the local endemic earthworm populations as well as the local endemic soil micro-organisms to come check things out but then there will be less waiting as the majority of the nutrients will be laying in wait for use by plants, as the nutrients escape the worm castings they will be caught up by the charcoal (which is slowly releasing the nutrient it was soaked in as well as the worm casting/raw compost nutrients), In such a way I will have created a time released version of worm castings/compost and implemented a very simplified form of Terra Preta on my farm. I genuinely think I might be onto something with this. After all the heating of "the Wyrm" house will produce the needed bi-product of charcoal to place in the bins making it a one stop process in the digestive section of the new worm house! I also think that we have to be careful with all of this given that a combination of too much charcoal and too little active fertilizer could lead to some bad fertilizer lockup scenarios, so one must be careful. I do think that this will take 3-5 years to prove or disprove in one way or the other and to measure the merits of just such a system. I definetly don't condone anyone burning anything for char that isn't in itself a byproduct of some other agricultural purpose (wood heating, plant residue) and if one doesn't have access to charcoal that is a byproduct of heating itself then I certainly encourage using recycled material to make ones own charcoal producing facility on the cheap and in a green fashion if possible, don't put too much science it to it though  |
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Post by raymondo on Jan 18, 2009 15:21:48 GMT -5
Just a remark about wood versus field waste like corn stalks. A friend recently met a biochar researcher and this question came up. The researcher reckons that biochar from wood, twigs or leaves of trees will produce a biochar with a more diverse mineral content than one made from a corn plant. Trees have access to a much wider mineral spectrum than the average corn plant. In other words, deep roots. Of course, a broad mineral spectrum can be added in other ways, but I thought it was an interesting point.
In a small garden bed I created last year I added charcoal. I haven't noticed any difference but I didn't know about activating it then.
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Post by ceara on Feb 2, 2009 12:15:52 GMT -5
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Post by canadamike on Feb 2, 2009 18:39:50 GMT -5
ray, I can hardly see how it would act very fast unless activated as you say. After all, for the natives, it was an ongoing process and in dry conditions like yours, it must take more time to capture the nutrient. A sponge only starts to do its ''spongy'' thing once it is wet....
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