The search engine here often appears to be kinda broken. However, if you copy and paste this exact line into Google:

"terra preta" site:gardenweb.com

...you'll see links to a number of threads, many of them right here on this forum, regarding terra preta.

All the best,
-Patrick

Jbann23 asks:

"Am I crazy, desperate or just plain curious? Hope someone has tried this and could submit any results, positive or negative."

The original post about Terra Preta got pulled after someone mentionednevermind. It was a shame really; the discussion was enlightening and exciting IMO. Anyway, I had been sort of doing it (using charcoal) before the post, but after exploring around the Internet I went ahead and started using charcoal in everything. I suppose one could say I have been at it for two seasons and I do have an opinion on what I have learned. Please keep in mind that I am a simple organic gardener whose garden is used for growing food, not a laboratory set up for scientific study. I only offer what I have seen and what I am now doing.

The first thing I noticed was how the charcoal affected watering, both compost piles and in the garden. I use a lot less water and I do mean a lot less, and we are in the middle of a drought. Hay/straw mulch last longer, but leaf mulch decomposes faster and completely. The soil is darker, almost black, warms up faster in the spring, yet holds heat in the fall. We gathered tomatoes well past Thanksgiving, and some of the collard plants are still out there growing, a year after planting. The watermelons and cantaloupes were fantastic (one 60 pound Black Diamond), but the honeydew never did ripen. I have not grown plants like this before as it relates to results. Everything is so easy to maintain, both plants and compost piles. The compost is finished and cured faster, with less turning.

I usually add ¾ inch of compost each season, but this year I wouldnÂt dare add that much. So far the few things I have planted I only added fresh compost to the planting holes, and they are out there right now going nuts (growing). The lasagna beds I built last year with charcoal wonÂt get any compost added, it would be a waste. However I will amend the soil with half the fertilizer I used last year to see what happens. I am going to have a lot of extra compost this year.

One more thing, I accidentally started a worm bed last year. I had some extra rabbit and goat manure so I put it in a wooden crate I had found. I mixed in some leaves, coffee grounds, and charcoal to see if it would compost in the box or not. Well, last month I opened the box and kind of started digging in the leaves on the top, and there were thousands of worms and other bugs in the box. I have no idea how to get the worms out or how to start a new bed, but the compost in that box is a sight to see. I havenÂt dug too deep for fear of smashing some of the worms, but I am going to have to do something soon. Worms are rare around here, but not back there in that compost factory I own, not anymore.

There is so much more I could say about this, but I will stop. I have a theory, but I will wait to see if anyone else is using charcoal and what their results are. For now, charcoal goes in everything, including compost tea. IMO, this is exciting, amazing, and ongoingÂ

Blutranes

Blutranes,
What is your source of carbon?
I could use results like that.

George

George asked:

"What is your source of carbon?"

My first source is the fireplace; we use wood to heat the house during the winter. I purchased "welders gloves" to wear while reaching into the hot fireplace; they work really well for one wacko enough to reach into a hot hearth. Since the coals are so hot I douse them with alfalfa tea instead of water. I have found the added nutrition soaked into the charcoal is a plus.

Another good source is the town I live near; they burn limbs and felled trees throughout the year. The coals left from the bonfires are just laying there for the taking. The town also collects leaves, which they shred, and store in a neat pile; they too are for the taking. The town has a front-end loader to load my truck, thus I feel it is my civic duty to aid the town in getting rid of all those pesky leaves and mounds of charcoal.

The last source is a 55-gallon drum kiln I built that can be found at the link below. It is an excellent source of bio-char throughout the summer. I char missed picked squash, cucumbers, okra, watermelon and cantaloupe rinds, corn cobs, broken limbs off the property, pine cones, pecans, and all large stalks from plants. I tried charring manure once, but I got called so many profane names for that antic I decided to avoid that tactic in the future. I would not suggest you build a kiln if you live near people, that thing creates a lot of smoke for a long time. My closest neighbor (non-relative) is over two miles away, if they smell the smoke they are trespassing.

Finally, I use a meat grinder that I found in the barn to grind up the charcoal; it looks like the one right here. I am looking for a better way of grinding, but so far this is the easiest (except on the arms) and neatest way to get the job done. Some of the bigger limbs I get from town go into the compost bin, as well as some of the bio-char vegetables that are not quite thoroughly charred. All in all, getting charcoal is working out very well, save the sweat one has to spend getting the job done. I trust this starts the thinking wheels turning

Blutranes

"I am looking for a better way of grinding"

What about a chipper/shredder? Or would that nut grind it finely enough?

"Or would that nut grind it finely enough?"

I don't know Bp, everybody chips/shreds for me. I will look into finding someone who has one and check if it will work. Maybe I can get the town to shred the charcoal! Hot dang...

Blutranes

thanks for the update, Blutranes - I was wondering how things were working out with the charcoal experiment. What kind of quantity are you adding to your garden beds? I'm ready to grind up and spread some in my lasagna beds...

I don't know how much carbon you're talking or how big the pieces are, but there are small electric shredders that can handle up to 1 1/4 inch diameter stuff that cost just over $100. I bought this one a few years back. I've never used it on charcoal, but it does smaller branches just fine.

Hey Melonhedd,

You said: "What kind of quantity are you adding to your garden beds?"

I am adding charcoal to the compost before I add it to the beds. To give you an idea of how much let me describe it like this:

To a wheelbarrow full of compost I would add @ ½ gallon of charcoal. All you want is charcoal sprinkled throughout the compost, and the pieces can be a variety of sizes. The amazing thing is that the plants find the charcoal, and then send roots through it. I have found plants growing in my compost piles with roots grown through the charcoal when I pulled the plant out. It doesnt happen for all plants, but I am not surprised when I pull a plant with charcoal attached any longer, I expect it.

How deep to put the charcoal in the soil is a decision one has to make on their own based on where one feels the charcoal should be located. I have not tilled mine in, however, I have worked charcoal in as I plant plants, digging up root crops, and pulling the few weeds I find. A friend of mine in town did till his compost/charcoal in last year. He was starting with soil that was not amended (no compost), and he got fantastic results. And too, he used synthetic fertilizer, his tomatoes were slow to ripen on the vine; mine didnt suffer that delay. However, this year he didnt even bring up tilling when we added his compost, he asked for my fertilizer blend, and his tomatoes are off and running already. I guess one can say he learned something last time. Last year they put his tomato bed in the newspaper, the plants were huge, with tomatoes in clusters like on a grapevine. Everyone else in towns tomatoes died of black spot disease, his and mine didnt.

IMO, using charcoal and the amount to use is just like making a compost pile, one gets a "feel" for how much green/brown mixture that one "feels" comfortable with. Put as much as you feel is right Melon, I dont believe you will be wrong. I would want my charcoal deep enough for the roots to find the charcoal however. Some are trying to make this technical; in reality all we are doing is adding another amendment to the soil

Blutranes

thanks, dude - hopefully I'll have some good results to report next year....

Here is some good advice (copy/pasted from the PDF linked below):

[Do put charcoal in soil but]
Do not put fresh charcoal into the soil!

If you put fresh charcoal into soil the fertility might actually decrease. In addition, we have noticed charcoal has a hydrophobic property that needs to be biodegraded before water borne nutrients can be transmitted into the internal structure of what was once the vascular system of the plant. In the conditioning process, the large inner surface of charcoal causes nutrients to adhere making them temporarily unavailable until the charcoal is saturated. Once saturated the charcoal becomes attractive to plant roots and soil microbes. Because of the inorganic nature of this substrate the charcoal will serve as an enrichment culture for nitrogen fixing and mycorrhizial partners.

How to do it

Think about composting with manure, urine, wood chips and /or nitrogen fixed by legume crops before or after use. We have been working on this approach as have others. Our local group has found that several months in these conditions, kept in aerobic conditions the charcoal is water saturated and completely involved with fungi and macroscopic invertebrates. Our best results thus far are with charcoal treated in this way.

If you are thinking about making agricultural charcoal you should know there is additional components of this conversion that benefits plants, this is smoke (pyroligneous acid) and burned soil. See Christoph Steiners dissertation, pages 35 to 42. This is the chapter on current indigenous gardening methods. Terra Queimada - burned soil and Terra Cheirosa - smelling soil (pyroligneous acid) as well as the volatile materials that accompany fresh charcoal stimulate microbial activity. TPp or Terra Preta (prehistoric) is in anthropogenic deposits dated 500 to 2500 years old and has a different respiration response profile than the newly created TPn orTerra Preta Nova. You cannot expect to make TP overnight. It will always be a work in progress.

Or one can soak the charcoal in compost tea, alfalfa tea, comfrey tea, or some other homemade brew to saturate the charcoal IMO...

Blutranes

I live in an urban area that if I tried to make charcoal firetrucks would soon be screeching up to my door and I bet I could even be ticketed for burning.

I was wondering if this type of agricultural charcoal used to mitigate pesticide spills would be a worthwhile addition to the compost pile. (see link)

It is available from the following companies:

" Activated charcoal is manufactured by many companies, such as ICI Americas, Inc. and West Virginia Pulp and Paper Company. It is available through your local agricultural chemical dealer. Two commonly used agricultural carbons are Gro-Safe (ICI Americas) and NuChar S-A (Westvaco). Activated charcoal usually costs about $1 per pound or less."

The article also says you really don't have to worry about putting too much on a field. I was planning , however, to add to compost after reading blutranes experiences and the interesting link provided above. I live in the sub-tropics (sandy soil) and do try to amend with sorely needed organic matter.

(( concerning grinding charcoal--just ran across a little blurb where someone mentions they put charcoal in a strong poly bag and then run over it with car to crush it.))

If you are thinking about making agricultural charcoal you should know there is additional components of this conversion that benefits plants, this is smoke (pyroligneous acid) and burned soil.

We won't be setting our Soil Food Web on fire over here at Blutranes house; trust me on that one. However, it is good to see someone else confirm what I have been saying for the last two years, I am humbled to learn this. Nonetheless, I do believe soaking in some sort of organic tea (or liquid kelp, fish emulsion, or sea salt finds) is faster and more effective than just adding to the compost pile, and the results are more immediate IMO. Also, using organic techniques (compost, humus) instead of just adding charcoal to the soil makes more sense to me, but large scale farming may differ with that approach. Again, we won't be smoking or burning any microorganisms around here on purpose.

Faree said:

I was wondering if this type of agricultural charcoal used to mitigate pesticide spills would be a worthwhile addition to the compost pile.

IMO it should work, but those who advocate biochar may have a different opinion. And too, one may want to look into the price of "Cowboy Charcoal" as a comparison of price to see which is cheaper on the wallet. Cowboy Charcoal is available at Lowe's is my understanding. As stated in the link above yours Farkee, roots of plants grow through the chunks of charcoal once the charcoal is in the soil, and the powder mentioned in your link may be too small for this to occur. Blending both types of charcoal may be the answer. It would serve the community if you find out the answer and let us all know, we would be grateful.

Soils in cooler climates and richer in mineral content may not have to use as much charcoal as those in sub-tropical climates, but the results should be just as dynamic IMO. This too is something that may be revealed later...

Blutranes

I poked around on the internet after last year's thread on charcoal. I didn't understand it as fully as I do now, but couldn't see any harm. Since my sons love backyard campfires and associated food cooked over same, I just cleaned the site and added to my compost, and some in a raised bed.

I don't have specific results for comparison, my raised beds always do better than the regular ones, and my compost added plants always do better than my neighbors. Certainly everything is doing very well, and what would I have done with the char otherwise?

Hi Blutrane,

Thanks for the postings re. charcoal. I have checked the availability of Cowboy Charcoal and the closest to me is in Bellingham, Wa.

Have to start checking around if anyone I know is travelling south and bring back several bags for me.
Any preference between Hickory and Mesquite? Thanks.

Otis

Otis11 asked:

"Any preference between Hickory and Mesquite? Thanks."

Otis11, I admire your enthusiasm about all this, you remind me ofme.

Not really Otis11, either should work just fine. What "Paleothrid" said above is important and true, the charcoal works best when soaked in a solution until saturated. I believe this is the reason the soil microorganisms are eating the charcoal. We dumped a drum of compost into the back of the truck of my friend Ed and could find few pieces of charcoal in the compost. Some of those pieces were soft enough to smash between the tips of my fingers, they are eating the charcoal. And too, what "Toxcrusadr" said about coating the compost and humus is correct as well, I am thinking this is one of the reasons the compost is so black. My granddaughter likes to play in the garden; she comes out looking like she has been playing in a coal yard (her mother is not a happy camper after she does).

Right now I am using "alfalfa tea" to soak the charcoal in; beware that it does stink to high heaven until the charcoal adsorbs the odor. My main reason is for the growth hormones found in alfalfa, plus the combination of carbon, fish, seaweed, and Epson salts appears to be a combination the soil food web finds irresistible. I know the worms love it; they look like they need to go on a diet. Of course one could make different additions; that is a matter of personal choice. Click the link below if you are interested in learning how to make it.

This thread is full of a lot of good information, congratulations on your efforts. As they say, seek and ye shall find

Blutranes

I just saw on my local Freecycle list that someone is offering 100 lb of Calgon granular activated charcoal. Hmmm... :-] Email sent.

Blutranes,
thanks for replying. On a side note, as proof of the advantages of charcoal (for people who couldn't be bothered w. scientific stuff), orchid mix ALWAYS has charcoal in it.
Otis

Tox, you are a lucky duck if you get your hands on that!

I've decided to try using activated carbon in my initial potting soil prior to transplanting in the garden. I will mix the carbon with compost, alfalfa, mycorrhyzal fungi and molasses (anything else I should be throwing in there??). I plan on letting it sit my basement throughout the winter and will oxygenate it just prior to adding any to my potting mixtures. I'll grow some controls as a comparison.

otis, My orchid has charcoal in the "soil mix" and it is a beauty. It has 7 bloom stalks getting ready to bloom.

wayne,
and you'll probably enjoy the flowers for as long as 2 months or so. Congrats!
Otis

I live in the country, so can burn free tree branches/limbs (mostly mequite and live oak) collected by the county.
When the fire is hot, I spread it out so as not to completely incinerate all the wood.

Ashes get screened/separated from charred material. Solids get pulverized through the a 1/4" screen of my shredder/chipper and soaked in (non-aerated) compost 'tea' concentrate, then added to my compost pile (to green layers) during a new build.

Also add pulverized char-solids to my "Slush Bucket".

I make a new compost pile every 7-10 days, so fine-chopped kitchen and garden refuse (my garden is produces year-round in zone 9) go into a cut-down barrel with diluted compost 'tea' [concentrate], some fresh compost and molasses (which gets aerated regularly).

Then during the next pile-build, S.B material is tossed(liquid and all) on top of a middle layer (at about 20" - 24" height in the build process) of dry grass clippings, then continue the manure/grass-hay layering.

My Slush Bucket does not have an odor, and the high-carbon (charred wood) content seems to significantly aid microbial decomposition - both while material is in the S.B., and in the compost pile material after adding it.

My composting process is quite different than most, but thought I'd toss my method into the 'mix' as 'food for thought'.

Robert

Canuckristani asked:

"I will mix the carbon with compost, alfalfa, mycorrhyzal fungi and molasses (anything else I should be throwing in there??)."

That depends on what you are planning to grow. For flowers the normal directions provided for growing flowers could be the guiding force in the final decision. However, if food crops are the goal other considerations may be in order.

"The alarming fact is that foods (fruits, vegetables and grains) now being raised on millions of acres of land that no longer contain enough of certain minerals are starving us - no matter how much of them we eat. No man of today can eat enough fruits and vegetables to supply his system with the minerals he requires for perfect health because his stomach isn't big enough to hold them." (See link below)

With the above in mind, my thinking is we might as well get good food quality from our efforts as well as saving on food costs. Maximum nutritional quality appears to be an easy obtainable goal due to the nature of biochar and compost. The addition of seaweed/kelp, sea-salt finds, rock dusts, or other full spectrum organic fertilizers can be considerations. Molasses could be of limited benefit, the soil food web should be active without its use IMO

Blutranes

i soak mine in a container with fresh chicken waste.
SSSH. don't tell anyone. very gross.
i also add it straight to hot spots... doesn't cool down untill it;s green stuff is completely gone so i haven;t knowticed the problem others have mentioned on the subject "yet"...
only time will tell

"The original post about Terra Preta got pulled after someone mentionednevermind"

AHHH Now you got me curious!!

Anyways, in terms of making my own charcoal, in my small suburban neighborhood, that's just virtually impossible. I did read somewhere here about "rolling mills" that give away huge drums of charred hulls and such...problem is that I don't know of any such place near DC where I live

Found this link. Looks like a good price.
http://www.acehardware.com/sm-free-shipping-to-your-local-ace--pi-1755124.html

I just stumbled across this post and I'm very curious. I've seen alot mentioned about hard woods. Just wondering if pines are also useable? If so I think camp grounds would be a great source of charred wood. Used to do some camping and never saw a camp site without charred wood in the fire pit, but it is usually pine.

Good gardening, Mary