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Terra Preta - Dark Soil - Experiment

I heard about the terra preta first time last year and I'm sold about the idea, it's a great supplement for my outdoor grows and I hope the result will be a bit better than last year :) :)
 

SilverSurfer_OG

Living Organic Soil...
ICMag Donor
Veteran
Thinking the easiest way to make large amounts of char hassle free is just to dig a big hole around a metre or so in depth (preferably with some kind of machine but could be done manually no worries in softer soil than around these parts which is full of rocks) and just start a burn in there.

Keep adding dry branches etc and then when the hole is full right up put a sprinkler/hose on it for a few hours to completely cool it all down.

The only downside would be having to get in the hole with a shovel but it weighs fuck all so not a biggie!

:smoweed:
 

SilverSurfer_OG

Living Organic Soil...
ICMag Donor
Veteran
Actually i guess in heavy clay i might end up with a bit of a pond... but thats cool i would just have to scoop out the char with a net or something... the water would drain away eventually. I want to combine hugelkulture with biochar amended top soil for the mother of all wins! ;)
 

chambabird

New member
Hi Silversurfer,

I have been having great success using a method similar to the one you describe, just with a few differences:

First I dig a deep hole of around 1 meter by 1 meter (depending on how much char I want to make).

I then cut a 45 degree channel on the side of the hole from the base to the ground above. Into this is inserted an old scaffolding pole (a hollow metal pole able to resist high heat without melting). This is vital to keep the fire going at the early stages. If you just dig a hole the fire will really struggle, and may not get hot enough to produce plenty of char. Instead you get lots of burned wood bits and a bit of char.

You can also use a bicycle pump to get it going by aiming the end down the scaffolding pipe. Kinda handy.

I then fill the hole and burn whatever hardwood I have available. As long as its not too sappy/resinous it will produce good char. Very sappy wood like pine can burn a bit fast/hot.

I wait until all the hole is glowing embers. Like the cherry on the end of a joint.

I place a big metal cover over the hole. I use an old bit of scrap metal i cut to size. This is then covered with soil and the scaffolding pipe end is covered over.

Wait a fair while, like four days to a week. If you are impatient and open it too soon it can combust again and you loose your char. Its ready when the metal lid is totally cold to the touch.

I then crush the char I collect in an old fertiliser sack by stamping on it like a maniac. You get the odd hard lump and loads of perfect char powder. Happy days.
 

SilverSurfer_OG

Living Organic Soil...
ICMag Donor
Veteran
Hey chambabird thats rad and just the kind of information we need good job. Got any pics?

Been thinking about getting my char on now its spring time in these parts.

Got a big ass pile of dry wood i was gonna turn into a hugulkulture but i have realised its way too close to some big ass gum trees so not the best spot.

Char and compost shall be the go :peacock:
 

SilverSurfer_OG

Living Organic Soil...
ICMag Donor
Veteran
Made a fresh batch including a bucket of various bones i had collected. It burned for about 5 hours and i added lots of chopped up dry tree branches... started pissing it down with rain about an hour in but the fire was plenty hot enough to keep burning regardless...

I made this brick kiln a few years ago and it works well. Dug into the side of a small slope. It has a lid and i was sealing it up with a bit of mud on top of the bricks to finish the charring process and eliminate air getting in. Now i find its easier to just position hose over the top on shower mode. Let it run for an hour or so and its done.

Have about a wheelbarrows worth which i will add to my latest compost heap. I add most char crushed and sprinkled over the bottom to capture runoff and near the top to capture off gassing nitrogen.

Last pic is a piece of charred bone. It crushes up real easy like the rest... :hotbounce

 

BOMBAYCAT

Well-known member
Veteran
I pre-charged some BioChar with hydrolyzed fish/kelp fert so it would dry out by winter when I mix up some soil-less. Anyway I set the pH of the fish/kelp solution at 6.9 and poured it over the BioChar. Would the pH of the fert solution make any difference to the soil-less mix? I use about 10% Bio-Char in my mixture of soil-less.
 

SilverSurfer_OG

Living Organic Soil...
ICMag Donor
Veteran
Good to go dude if that mix is already working a wee bit of kelp/fish won't be too much of a worry. Sometimes i add some apple cider vinegar to counter balance the basic kelp/fish. But 10% char WILL make a big difference to your ph if it isn't aged long enough... if you are using sphagnum peat as your base should be sweet kitty cat ;)
 

farmerlion

Microbial Repositories
Premium user
Mentor
Veteran
420club
Hello all, I'm doing something very similar this season with dark soil. In ND. it's called Leonardite. A layer of vegetation between two layers of clay. Fully decomposed over millions of years. It's very high in humid acid and has generous levels of folic acid. I will be adding the fine ground material to my soil. I also have a liquid form I will use with my fish emulsions as a supplement. I will try and do a couple updates here along with the two threads documenting this grow. Peace
 

xet

Active member
One thing is certain: the finer the biochar the better.

The easiest way to powder your char after it is produced and hosed down with water to stop from burning is obtain a small concrete mixer and throw some decent sized rocks in to crush the char into a powder.

This makes the whole assimilation process front to back more seemless

IMG_1818.CR2_-600x620.jpg


The other thing is biochar lasts virtually forever in the soil so the idea is to continue planting in the same spot and charge the soil with various teas when needed and eventually the charge is self maintained through the expansion of the biosphere under the soil.

Last little tidbit: I have heard this TP can increase dozens of feet into the soil over time through water carry/transport eventually reaching the water table/well and creating a water/electric connection with the soil surface transporting microbes and electricity through the fungus web from the well to the surface which also cleans the well water and expands the bioweb even faster.

Happy growing
 

xet

Active member
Final note: covering the amendments/soil that are directly in the ground with any raw carbon material (leaves,sticks,chips,grass,) will burn into biochar over time usually ~3 years to total burn but doubles in use by trapping water in the soil further aiding the effort to eliminate bringing in a separate water source
 

SilverSurfer_OG

Living Organic Soil...
ICMag Donor
Veteran
Great idea with the cement mixer xet!

You won't make biochar with carbon as mulch but it will slowly break down into humus. This is mostly due to fungal activity and for sure biochar can increase all beneficial life and water retention (especially in sandy soils) in the soil including the ones that break down lignins and raw carbons. I think you are referring to Terra Preta which spreads and grows but this is still something of a mystery unless you have some new information? Got any links?? Cheers bro!
 

flylowgethigh

Non-growing Lurker
ICMag Donor
I am going to incorporate biochar into my soil. I think carbon is the missing link to my lack of frosty bud. This guy has game IMO. I like the way at the end he kinda reveals all the other stuff he mixes into his comost.

https://www.youtube.com/watch?v=0_IdgPmnbRU

XET: "Last little tidbit: I have heard this TP can increase dozens of feet into the soil over time through water carry/transport eventually reaching the water table/well and creating a water/electric connection with the soil surface transporting microbes and electricity through the fungus web from the well to the surface which also cleans the well water and expands the bioweb even faster."

Edit: I read above the comment on electrical and microbes. I use a single probe pH meter to measure the amount of ionization goin on in my soil. When the roots are active, the meter reads a low number like 3.5, and I know the pH is not that low, but instead is an indication that a good amount of "sparking" is going on.

Carbon is very conductive. It may also help the spark somehow.

what about adding wood ash to the mix?
 
Last edited:

trichrider

Kiss My Ring
Veteran
I am going to incorporate biochar into my soil. I think carbon is the missing link to my lack of frosty bud. This guy has game IMO. I like the way at the end he kinda reveals all the other stuff he mixes into his comost.

https://www.youtube.com/watch?v=0_IdgPmnbRU

XET: "Last little tidbit: I have heard this TP can increase dozens of feet into the soil over time through water carry/transport eventually reaching the water table/well and creating a water/electric connection with the soil surface transporting microbes and electricity through the fungus web from the well to the surface which also cleans the well water and expands the bioweb even faster."

Edit: I read above the comment on electrical and microbes. I use a single probe pH meter to measure the amount of ionization goin on in my soil. When the roots are active, the meter reads a low number like 3.5, and I know the pH is not that low, but instead is an indication that a good amount of "sparking" is going on.

Carbon is very conductive. It may also help the spark somehow.

what about adding wood ash to the mix?

you should know wood ash is very basic. mostly potassium, and will alter your PH radically so ease it in.
i believe carbon to be neutral by itself and only acquires +/- PH with addition of additives like you suggested adding ash or other amendments.
biochar is not terra preta but a component thereof.
 

trichrider

Kiss My Ring
Veteran
yeah.
been using biochar since Crush was in 'hard mode'.
LOL, not many will recognize that reference.
remember to 'charge' your char.
 

flylowgethigh

Non-growing Lurker
ICMag Donor
Can a guy use urea or amonium nitrate to charge the biochar with nitrogen, or does it have to be urine or something like that?

I have a scrap bucket off a big heavy eqpt loader, and I am going to try using it as a contiki. About a couple yards capacity. Making biochar would solve a problem of getting rid of tree branches and fallen trees. I have to figure out how to dump the water/biochar and not make a mess, and be able to reload it and repeat. Concrete slab with a U-shaped back wall that drains, is all I can think of so far. Dump, dry, size, scoop, relocate, and make a row. Add to the row as more material is made. Charge from on top, like I do the wood chip row.
 

trichrider

Kiss My Ring
Veteran
you could bury your yard waste in a pit, start the fire, and then bury the fire.
you want little to no oxygen getting at it. when fire is out uncover the char.
no water needed.
you mention rows...well dig your pit where the row will be and little need to relocate.
do you have animals? charge with their excrement.
 

420empire

Well-known member
Veteran
Hey Trichrider.
Sound like a nice and easy method to make biochar. When you mention to bury the fire, do u do this when there is only ambers, or should one do this while the fire is going ? And by adding let´s say chickenpoop would you stir it up with water and pour over the char?

Cheers. :thank you:
 
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