Terra Preta - The parent thread which started it all

[davidgmills]

On the day before Valentine's day, I bought my wife some herbs and put them in a single pot with my homemade terra preta.

The news is bad for my cilantro. The rosemary is doing great.

What did I do wrong to my cilantro? Soil is well drained. TP stayed surprisingly moist. I am wondering if cilantro can not stand the excess water retention of TP. Any ideas?

[davidgmills]

I have read numerous times here to not disturb the soil much or turn it.

While that may be a good idea if the charcoal is pulverized, from what I see it would take a lot longer to get lump sized charcoal degraded to particle size if the soil is not frequently tilled.

I intentionally did not pulverize my lump charcoal just to see how quickly it would degrade into smaller pieces. What I find is that constantly turning it exposes the charcoal to new soil and it degrades much faster.

[malcolmf]

Originally Posted by RBlack

I am trying to char up my kitchen wates and am going to char (if possible), cow and horse manure, and pine needles both dried and fresh.

RB. I'd stick to dried as much as possible. Simple physics. Energy is required to drive off moisture. This is the first stage of the process, during which the temperature stays at just above 100 degC and no carbonisation can occur. The amount of energy can be precisely calculated from the specific heat of water and the latent heat of vapourisation for that quantity of water. In a traditional method like yours, the energy must come from the combustion of some of the feedstock. You could easily waste a third of your feedstock if it is not dried.

So I suggest that you separate harder feedstock (including pine needles) and let it dry, preferably under cover. Maybe if you manage to organise a group from your audience you could even use the heat or emissions from one burn to help dry the next (e.g. Making charcoal and preserving wood). Compost softer stuff or just chop it up raw as the Amerindians would, and mulch it on top of the char. Let the worms take it down for you and the fungi that will colonise the charcoal turn it rapidly into available nutrients.

One experiment is to compare mulch without char and mulch with char in adjacent patches. I've read somewhere (I forget where) that char speeds decomposition.

Sounds like there could be some really choice smells coming from your burn

M

[malcolmf]

Originally Posted by Michaelangelica

The presentation has nice pics. but is a bit light on detail

I posted the link only because some of the pictures tell us more than a thousand words could. For the words, see Hecht & Posey quoted several pages above, or Hecht in Amazonian Dark Earths.

Do you know the relative amounts of charcoal in mulata and preta?
(preta is for every 1 meter of depth of soil, is between 147 and 506 tonnes of charcoal per hectare)

According to Kampf et al in Amazonian Dark Earths the median soil organic carbon of preta is 36.7 g kg-1 and of mulata is 21.0 g kg-1. To convert your units, they give preta's min and max as 24 and 98 g kg-1. I can't find a figure for actual charcoal.

Could you please explain?

No. But if you google "immunoreactive protein assay" you can see how standard it is. There are several kinds of assay, and my understanding is that immunoreactive glomalin is only a part of total glomalin and indicates more recently formed stuff, which helps to work out turnover rates. To me this also says that glomalin must be a catch-all word for something whose true detailed composition has yet to be determined.

M

[malcolmf]

Originally Posted by davidgmills

I have read numerous times here to not disturb the soil much or turn it.

While that may be a good idea if the charcoal is pulverized, from what I see it would take a lot longer to get lump sized charcoal degraded to particle size if the soil is not frequently tilled.

I intentionally did not pulverize my lump charcoal just to see how quickly it would degrade into smaller pieces. What I find is that constantly turning it exposes the charcoal to new soil and it degrades much faster.

David
I understand this. But you need to find out whether you are making terra preta or just burying charcoal to little effect on your soil fertility or the atmosphere. Digging could be destroying the soil structures and organisms that increase fertility and protect the carbon from decomposition. If so, what's the point in digging? Glaser writes in Amazonian Dark Earths (p153, without himself giving a reference) that "it is known that ADEs were not tilled by the native population", and this matches Hecht's present-day observations. Her observations and soil analyses suggest that the char they added was not lumpwood charcoal, just the residue from all manner of incomplete burning.

Try using crushed char under mulch and let worms do the burying for you. They may be slow but my word are they thorough.

M

[malcolmf]

I like Susanna Hecht's translation from the Kayapo: "Cool Fire". Sounds like a great slogan for a movement.
M

[malcolmf]

To RB

Thanks for the kind words, but we are not likely to be admired much by the terra preta researchers. I've read their stuff. It is way out there. We aren't being scientific. But what we are doing, and what the world needs as much as their work, is throwing ideas around about how carbon burial and the modern world might meet in reality rather than in theory. What can Everyman and Everywoman do rather than wait for a technology that may never show up? Maybe one of these ideas will spread, who knows. All I know is that this feels better than sitting around waiting for the world to fry and feeling both guilty and powerless, like most everyone I know feels about global warming. (Which suggests society is heading for a communal neurosis that would let the extremists loose.)

Originally Posted by RBlack

note the particle size comments on p. 355. This gets into the idea that the Amazonian Indians didn't screen their char through a #50 screen but just sort of used it as is.

Hold on, Lehmann's paper is a modern experiment and says nothing about what the Amerindians did.

There does seem to be a fair amount of evidence that the charcoal in the soil adsorbs some of the microbial gas emissions.

Not sure about this. Activated charcoal, yes, but that is from high temperature pyrolysis and I don't think it occurs in TP. Another explanation, to me more likely, is that the reduction in emissions is directly related to the increase in compounds protected from decomposition within TP soil aggregates, a physical effect rather than a chemical one. Perhaps "all of the above" is the right answer. The issue underlines a need to analyse TP for glomalin and its effects on aggregation, pronto.

So when calculating the carbon sequestration benefits we need to take into account:
1. actual carbon put into the soil
2. reduction of CO2 emissions and increase of SOM (made from carbon/stores carbon)
3. the amount of carbon taking from the atmosphere by increased biomass production due to soil fertility (if charred and put back into the soil)

Where is point 2 from? CH4 and N2O emissions are reduced, but who has measured CO2?
To 3 I would add increased glomalin storage from increased fungal biomass. It can be huge over time (6% by weight of one Hawaiian forest soil).

[erich]

The process engineer from Clorox (KingsFord Charcoal) joined my TP list About the Terra Preta Discussion List and Website at Bioenergylists.org | Terra Preta

I contacted him about six months ago and got a short reply of "Interesting proposition". According to his first post to the list I would say he is definitively interested. They have production Retorts I know of in West Virginia and Illinois , and probly many more places. They have many grades of char.


To: terrapreta at bioenergylists.org
Subject: [Terrapreta] Wood Char Available



To TerraPreta Discussion Group:
I've been following the discussion on here for a while now. If you folks
have an idea of the amount of char volume that you are needing, I may be
able to help you in obtaining truckload quantities.
Just send me an email and I'll be in touch.
Also, I have many years experience in the chemical engineering around
industrial pyrolysis of wood and biomass, the equipment available, what is
generally used, what is being researched, as well as the attributes of chars
and how they are affected by pyrolysis operating conditions. Let me know if
you need anything specific.

Thomas Beer
Manufacturing Technology
Clorox Services Company
3900 Kennesaw 75 Parkway, Suite 100
Kennesaw, GA 30144
770-426-2419
770-426-2428- FAX
770-364-1079- Cell


Seems my fishing expositions are paying off.
Erich

[malcolmf]

Suggest you read this post in another forum from a guy who unknowingly created something that behaves like TP by a combination of keeping chickens and periodic burning.

I can imagine an early Amerindian discussing something similar with his mates. "All I did was burn our smelly stuff there for a few months, and now look at it ..."

I'm beginning to wonder if terra preta implies a total rethink of household waste separation and collection as it is done today in so-called developed countries. Even recycling seems too stupid now, and household chemicals more of a problem than I thought.

M

[maikeru]

Originally Posted by davidgmills

On the day before Valentine's day, I bought my wife some herbs and put them in a single pot with my homemade terra preta.

The news is bad for my cilantro. The rosemary is doing great.

What did I do wrong to my cilantro? Soil is well drained. TP stayed surprisingly moist. I am wondering if cilantro can not stand the excess water retention of TP. Any ideas?

I know this sounds obvious, but different plants have different nutrient requirements. Your cilantro may be suffering from some kind of nutrient deficiency or induced nutrient deficiency because of the charcoal in the soil. And, IIRC, cilantro, when given the chance, will grow faster than rosemary. My rosemary seems to grow rather slowly but steadily. (Edit: I just remembered one more thing after I posted this. Rosemary thrives in poor but well-drained soil. So it may not be as picky as the cilantro when it comes to growing conditions.) The charcoal needs to be saturated with nutrients and after a while I think the soil ecosystem gets going and works with the plants to help improve growth.

I'm growing cilantro in terra preta and it does very well, but I've intentionally added a lot of different things to my terra preta, so I think there are a good collection of nutrients in it. As a quick fix, try adding some dried, low-sodium seaweed. Seaweed is a good source of trace elements and minerals as well as calcium, iron, and potassium. It also has growth hormones in it which may boost plant growth and health in the short-term. I also believe that terra preta has to be "tailored" to a certain extent for the plants intended to grow in it. Leafy plants require more N in the soil. Flowering and fruiting plants may require more K than N. In general, just try to enrich the soil with everything you can get your hands on.


Worse than having plants that don't grow is watching them be taken over by whiteflies. My mother purchased some herbs from the supermarket which have whiteflies, and they're in the same room as my garden, and my plants are infested... Disaster seems to strike when I least expect it. And worse that I didn't notice 'til too late what with being busy recently. The experiment will be over soon, although it has been wonderful and more productive than I ever expected. For example, I've never seen green onions which were 0.5 inches thick or more and 1.5 - 2 feet tall. They even tolerated the winter cold surprisingly well.

I will restart a new indoor herb garden in a few weeks, with the coming of spring, and I will take my current terra preta and use it in the outdoor garden. However, the new terra preta garden will probably use powdered activated charcoal, so I can make more pots more quickly and with less backbreaking effort. I found a site which sells horticultural powdered charcoal. And I will write about my results and take a few pictures to show on the forum.