Does anyone use terra preta?

Does any one here use it? I know verry little about Terra preta and i would appreciate any help you may have on how i could make and apply it.

search the forum for "char" or "biochar." I'm fairly certain you'll get some good hits.

ive been using it for years here, its gotta be one of the few things that transformed my soil from crap to pure black gold.

look into pyrolised rice hulls. very easy to make, no need to smash to size, easy to apply, its a waste product from big farming, and its cheap.

followed by wood chip char.

the good thing is you only need to do it initially as the stuff stays in your soil doing its job for a very very long time.

Jordan Lowery wrote:the good thing is you only need to do it initially as the stuff stays in your soil doing its job for a very very long time.

this article was posted elsewhere on the forum. it suggests that char doesn't last as long as previously believed. still a long time, though, with around 25% lost every century.

I am constantly burning biochar and incorporating it into my soil everywhere. I have access to enough wood waste that there's room for this and a full-on hugelkultur component to my design.

While biochar makes up a percentage of terra preta, I'm pretty sure that biochar does not equal terra preta. There's a whole lot more to it than just the nitrogen treated charcoal. Humanure was also a very important additive. Also, based on what I've come across, biochar is more important for tropical areas than temperate areas, the charcoal helps keep the nitrogen in place in the soil instead of it just washing away. Up here in the northern part of America we have the capability to make pretty good humus without using charcoal.

from what i have seen here the most beneficial effect on the soil from the char is not nutrient holding, not even water holding, but biological stimulant. it just does something to the soil where day one you have no worms or life, then a few seasons later your shoveling them out by the dozens.

ive been known to char logs and such before tossing them into hugel beds. from the few years they have been going the beds with some charred logs are winning over the rotten log beds. both are far better than the native soil without permaculture practices. i find charring the logs for the most part to be too much work, making rice hull char is almost effortless, it mixes well with compost, and can be spread on the topsoil easily.

Isaac Hill wrote:Up here in the northern part of America we have the capability to make pretty good humus without using charcoal.

Well I'm "up here in the northern part of America," and whereas my entire five acres, sitting on glacial till, is mostly gravel, and whereas it percs like a sieve, and whereas it rains like hell around here, and whereas it dries out altogether in the summer months, therefore I conclude that I need to add all the water-holding capacity to my soil that it can get -- to hold water in the dry months and prevent nutrient leaching in the wet months.

And whereas I have enough wood waste available to both practice hugelkultur AND burn biochar, and thereby manufacture terra preta using plenty of manure and other elements added to the biochar, and whereas that manufactures pretty good humus AND pretty good terra preta, then that's what I'll jolly well do.

See, everybody's soil is different, everybody's situation is different, and everybody's design is different, and these kind of blanket generalizations aren't really very helpful.

Nickolas Mcsweeney wrote:Does any one here use it? I know verry little about Terra preta and i would appreciate any help you may have on how i could make and apply it.

Nick,
We do LOTS of TSI (Timber Stand Improvement) and routinely handle mega-tons of brush. The best way we've found is to get small burns going as we prune and thin mostly dead wood. Once we have a fair bed of coals we load fuel on the fire and then smother it (nearly) with soil. This gives the low-oxygen smolder that charcoal producers (biochar) have used for centuries.

The ash and charcoal mix is a wonderful soil amendment, and goes into the foundation of most of our beds and plots. The activity also cuts down on the fuel load and greatly reduces the odds of and damage from wildfire. This conversion to char means we can store carbon in the soil for very long periods of time while greatly stimulating the level of biological activity in the soil.

I'm in northern America as well. Much of the early forests being cleared for agriculture were burned for the ash. Much ash was put in barrels and shipped by lake barges to Chicago for fertilizer.

One real advantage of biochar is that it allows for gas exchange of roots and stabilization of the soil structure. Nutrients can be washed away in the rain and in heavy clay soils like we have here in NW OR, plant roots can't breathe or exchange O or CO2. Biochar lets enough oxygen into the soil so that it can store some water and exchange gases.

By the way, I don't buy the biochar versus hugulkultur bit. I plan to do both. I think they do different but in some ways similar things.
John S
PDX OR

From what I've been able to dig up on google scholar, biochar has a few different effects on soil:

1: It raises pH of acid soils to levels within the range for optimal plant nutrient uptake.

2: It increases cation exchange capacity of the soil (CEC). CEC of biochar increases dramatically over time as its surface oxidizes, increasing ~5 fold over just the first year in the soil. Mixing biochar with manure increases the rate of CEC increase.

3: It suppresses the activity of toxic iron and aluminum radicals that are abundant in heavily weathered soils.

4: It reduces nitrogen availability, which stimulates legumes to fix more nitrogen and produce up to 40% more biomass, and can increase bean/pea yields up to 50%.

5: It also provides several plant available nutrients including potassium, although biochar does not actually bind potassium to any significant degree and it leaches out in one year.

6: A few biochars can hold water, but this is strongly dependent on feedstock.

These benefits apply to any soil type and biochar does not significantly increase pH in alkaline soils. Characteristics of biochar depend heavily on feedstock and temperature in general, with 350-450C being optimum. Surprisingly, the most worthless chars are from wood, with pine being the absolute worst, and hardwoods slightly better. The best chars come from legumes (dried hay and peanut shells) and straws, as well as a few nut hulls. Pecan hull char has a CEC out-of-kiln some 2.5x higher than the richest loam soils, which would increase more than tenfold after just two years in the soil.

M Troyka,
That's very interesting.

Surprisingly, the most worthless chars are from wood, with pine being the absolute worst, and hardwoods slightly better. The best chars come from legumes (dried hay and peanut shells) and straws, as well as a few nut hulls. Pecan hull char has a CEC out-of-kiln some 2.5x higher than the richest loam soils, which would increase more than tenfold after just two years in the soil.

Do you recall where you found the info about wood char being lousy? I'm currently looking at burning some slash piles for char -- have more than enough for hugel beds and wildlife habitat. Would like to get a little more deeply into whether it's worth the effort. Probably will still do it if only to increase the diversity of sizes of particles in my heavy clay soil, but more info = better.
Thanks,
Gani

This: Gaskin et al 2008.pdf

If you've got heavy clay and spare wood, it's certainly better than no char.

This paper details a study with wood char in columbia, which showed clearly beneficial results.

Also, looking those up I found a study on rice hull char. Thus far I haven't found anything on grain hulls, so this ought to be interesting.

EDIT: This is the paper I was referring to. I believe small grain husks make the list of high quality char materials.

Here's a link to an interesting biochar study in California soil.

I've been reading about this trying to decide if I should do this while digging new hugelkultur beds.
It would be a lot of extra work, but if its worthwhile, this would be the time to do it.


Does anyone know if biochar is as useful if the char is buried 1-2 feet deep versus applied to the top 6 inches of soil.




http://2012.biochar.us.com/374/potential-biochar-use-vineyard-systems

In this study the char didn't help the grape production, but did increase the cover crop production.

It depends on soil pH. In acid soils biochar can considerably increase productivity of all crops, but in neutral-alkaline soils it mainly increases nitrogen fixation and biomass of legumes.

There's not much benefit to burying the biochar unless you're planting a tree, and even then it's only worthwhile in acid soils.

If you're planning on building soil under your crops with legumes, or if you plan on planting legumes as a crop, I'd recommend going to the effort. Otherwise it probably won't do much for you.

Yes, that seems to be what the studies say. Beneficial in acid soils.
Since I fertilize legumes, I'd probably wouldn't see an increase there either.
Maybe I'll just throw old fireplace charcoal out, but no special effort.

Does anyone inoculate their biochar by soaking in manure tea, compost tea or urine? A fellow on YouTube soaked his in a mixture of forest soil and water all through the winter before applying to his garden. Apparently, the biochar needs to soak up nutrients and microbes before being useful, except to amend acid soil. For a larger scale, I was thinking of using the thinned sweetgums that are taking over my small pasture and burning them along strips laid to contour, covering with soil to char them. Then I can plant a legume/grain cover and let chickens run on it to fertilize it before planting it with any crops. It seems like it would be a lot cheaper than bringing in a bunch of lime and having it wash away each year. I daresay chickens bring in lots of other amendments, including minerals from the grit they eat.

Letting chickens run on it would be a great idea, I think. Soaking in microbes or urine doesn't really do anything, but leaving the char in contact with manure (or throwing it in a compost pile) helps the char "age" faster and increases its cation exchange capacity.

I think sweet gums make better hugelkultur than biochar though. Wood in general makes crappy char, other materials are more suitable (grass, nut/peanut shells).

Anybody know how to produce it in bulk simply?
I have lots of wood, but need an easy way to char it in bulk.
I don't know anybody here in South Australia that is making it...

Sara Harding wrote:Does anyone inoculate their biochar by soaking in manure tea, compost tea or urine? A fellow on YouTube soaked his in a mixture of forest soil and water all through the winter before applying to his garden.

Sure. I inoculate mine with comfrey juice, diluted in water 20 to 1, or manure tea. It is a necessary part of the process. I douse the fire with it. Soaks it all right in, immediately.

R. Morgan wrote:Anybody know how to produce it in bulk simply?

what's bulk to you?

tel jetson wrote:

R. Morgan wrote:Anybody know how to produce it in bulk simply?

what's bulk to you?

If I could have 100 cubic metres of it right now, that would be a start. I just spread 18 cubic metres of horse manure in one small paddock, and that only does about half of that small area. Practically, I suppose 5 cubic metres per batch would be a manageable amount....

R. Morgan wrote:
If I could have 100 cubic metres of it right now, that would be a start. I just spread 18 cubic metres of horse manure in one small paddock, and that only does about half of that small area. Practically, I suppose 5 cubic metres per batch would be a manageable amount....

I guess you could use one of the traditional charcoal burners' techniques. they mostly involve a big pile of wood set on fire and smothered with dirt. certainly not the cleanest option since most of the pyrolysis products remain unburned.

maybe you could make a retort out of a shipping container.

Ivan Weiss wrote:

Isaac Hill wrote:Up here in the northern part of America we have the capability to make pretty good humus without using charcoal.

Well I'm "up here in the northern part of America," and whereas my entire five acres, sitting on glacial till, is mostly gravel, and whereas it percs like a sieve, and whereas it rains like hell around here, and whereas it dries out altogether in the summer months, therefore I conclude that I need to add all the water-holding capacity to my soil that it can get -- to hold water in the dry months and prevent nutrient leaching in the wet months.

And whereas I have enough wood waste available to both practice hugelkultur AND burn biochar, and thereby manufacture terra preta using plenty of manure and other elements added to the biochar, and whereas that manufactures pretty good humus AND pretty good terra preta, then that's what I'll jolly well do.

See, everybody's soil is different, everybody's situation is different, and everybody's design is different, and these kind of blanket generalizations aren't really very helpful.

Hey there,

it seems you are doing some interesting work "up in the north".
What I did in northern Germany and now in Haiti is mixing the techniques and, therewith, the ingredients of the pile.
As biochar itself contains practically no nutrients for plant growth, but it has some significant advantages that improve soil quality, I build the raised beds up as follows:

- dig out a trench of about 20 cm and fill it with woody material to pile up to about 30 cm.
- add ground biochar mixed with soil to your pile, compress and water it
- add green manure as the next layer and add some ground biochar to it
- add richer organic material like kitchen waste, manure etc. with some green manure, continuously adding ground biochar to it.
- cover it all with a thin layer of biochar and about 10 cm of soil

The biochar in the pile soaks up released nutrients from the (mostly anaerobically) decomposing organic matter and makes the available for the plants. Plus it provides all the other advantages you know of (a home for microorganisms, water storage capacity, supporting funghi, etc.) and it stays in the soil for hundreds of years. This leads to extraordinary yields from beginning and to the development of a Terra Preta-like substrate.