Mel Landers and Jackie Foo on Field testing Corn Stover Stacks

The following posts from the Black Earth Soils newsgroup (Bionet) are well worth reading since we are addressing the possibility of restarting hand production were it is the only option.

Mel Landers:

arclein wrote: Their principle option was to use corn stover and I show how.

Thank you for sharing this idea. This is very helpful. Having grown Maize for a number of decades now, I can attest to what you have stated about its stacking capacity.

I also know the difficulty in utilizing Maize stumps if you don't burn them. (not that I ever thought to do so) The Amazon Basin can grow an amazing amount of biomass in a short period of time. (I have attached a photo I took four decades ago, when I introduced slash and mulch methods to the Urarina of Peru. It shows the abundance of biomass left on the soil after cutting tropical kudzu.) But, maize is a challenge to grow in that environment. The fact that maize pollen is so common attests value of dark earth soils and their ability to retain nutrients.

It makes sense that, women would long ago have turned to firing their pots in order to increase their strength and longevity. The clays in the upper Amazon Basin are high in sand. The area is one big flood plain with continual deposition of sand. If the same is true in the lower Amazon, their pots likely needed firing. I have also attached a photo of an Urarina woman making a pot. Notice the grey color of the clay. The pot I brought back with me had a very rough texture, due to the sand.

Why not turn to maize stumps to produce a high temperature fire. Place that fire under the soil, in an impromptu dirt oven, and you have maize charcoal. It would be easily powdered and once your soils started improving, it would have been plentiful as well. It is a short step ahead to do the process specifically for soil improvement. If anyone doubts that they might do this, they need to read the information written up by Suzanna Hecht on the practices of the Kayapo.

Here is a type of biomass that is even plentiful in the temperate zone. O.K.....I can hear Bob thinking....But, how can I stack the Maize stumps from a whole section of land. That is where a large scale pyrolysis retort comes in. But, here in Nicaragua and in many other maize growing regions of the world. Stacking by hand makes good sense.

Nicaraguan producers already think I'm crazy for wanting the grass they cut off the fields in preparation for plowing. Now they will think I am totally insane for requesting their maize stumps as well. This should be interesting! Thanks again!

mel

This is an excellent validation of the proposed mechanism

arclein wrote:

Hi I did a post describing a method of producing terra preta soils using only primative stick agriculture. Their principle option was to use corn stover and I show how.

I am hesitant about other feed stocks in general been as forgiving as corn stover, but that has to be shaken out through practice.

I also describe a modified incinerator design to utilize a full range of biomass in later posts.

The astounding revelation is that the Indians sustained continuous agriculture in the Amazon for centuries.

See my post at:

http://globalwarming-arclein.blogspot.com/2007/07/ carbonizing-corn-in-field.html

This has turned out to be my most popular post to date. Enjoy the site.

From Jacky Foo

Hi arclein

I checked your profile at www.blogger.com/profile but found no "real name" and therefore I address you as "arclein".

I have not made charcoal nor charred materials before and therefore I ask you.

Q: have you tested your idea of "carbonizing corn in the field" as described (Wednesday, July 4, 2007) in the link provided above ? or is there a drawing of what you described anywhere ?
>...the Indians in the Amazon likely created windrows that they
>then lightly buried and set afire. Your idea sounds very logical if the Amazonians were making charred materials (from corn stalks with their roots intact). But did they make charred materials to fertilise their soils or was charred materials simply a by-product of their burning away of agricultural wastes (corn stalk and tapioca stems) ? . (your message of Friday, July 6, 2007 "Those amazonian soils" in:

http://globalwarming-arclein.blogspot.com/2007_07_01_archive.html .

Given that we now want to make charred materials and we have corn stalks with their roots intact, the idea of stacking a windrow of two rows of corn stalks with their roots to form the outside walls is a good one.

So let's say I have 5 acres of corn where I could get 50 tons of stover. I have no machinery (nor container to make a kiln), just bare hands of the workers e.g. in Kenya.

How big (length and height) would this single windrow be ? What materials can I use to make the outer wall ? ...etc

regards jacky foo

arclein wrote:

However they began doing this, the rewards were immediate inasmuch as the soil retained fertility that would have completely disappeared in perhaps three years.

The volume of corn stover made this possible over the whole growing area so that there was no lack of biochar even at the very beginning. Most other likely sources would restrict you to treating a fraction of the original cropped area and likely not be very sustainable.

Right now, we are speculating. I would actually try to build a circle with the roots on the outside and see if it is possible to build a beehive shape as an experiment. I would leave a central chimney, probably because I had to, and fill the bottom of it with a well stamped mass of biowaste.

Once the beehive had reached the point of almost been closed off, I would throw a large mass of glowing coals into the chimney and then fill the chimney with corn stover with a dirt capping. Then I would stand by and shovel dirt on any breakthrough for the next few hours.

We can try other methods of stacking once we have a little experience. And no, no one has done this yet and I am keen to see how it goes.

regards

arclein

Discussion on Terra Preta (pollution impact)

Robert:

I hope we can agree that this is a method of producing charcoal that is more apt to be harmful that helpful for climate change reasons - and therefore should not be encouraged. The ancient Indians who might have produced char in this clever way didn't have the knowledge of how bad the CO, CH4, H2 and other gases are. We should.

Ron AND

Bob (cc terra preta list):

Last night, you responded to my expression of concern about too-serious emissions from in-field carbonization of corn stalks, saying (with responses interspersed):

> Hi Ron
>
> I do not actually agree with that. In ideal controlled
> circumstances which I demonstrated earlier in my blog,
> it is possible to get a completely reduced waste gas
> that is primarily CO2. In the meantime we get a
> maximal yield of either charcoal or lower temperature
> carbonized material.
>

[RWL: Thanks for reminding of your blog (shown below - nice work!). I think you are referring perhaps to a Canadian incinerator two-chamber system you wrote about - the first chamber being for pyrolysis. I like that. My concern is that the "ideal controlled circumstances" you refer to are going to be very difficult to achieve in the field. I don't understand your "meantime" - but guess you believe that the emissions that I feel are almost inevitable in the field (without some controls) are justified by the produced charcoal. I still think that could have been case 1000's of years ago - but not now.

> The method just described will be fairly less
> efficient since temperature cannot be controlled and
> the combustion gases cannot be superburned. This
> produces a lot of carbon monoxide instead.

RWL: Yup - and CH4 etc. - all polluting.
>
> However, a subsistance farmer does not have the type
> of tools we take for granted. And this
> new(ancient)method will produce a yield likely close
> to sixty to seventy percent of the best case.
>

RWL: Granted - but still something to avoid. My first recommendation is that the corn stover (or whatever) is worth bringing to a central location where the CO, CH4, etc can be combusted to serve a practical purpose - cooking being one such - but maybe electrical production, etc.

> And that product, however obtained will sequester
> carbon for decades, if not centuries.

RWL: Agreed - maybe millenia. But I feel we on this list must do all we can to avoid char production that is polluting. I am certain that there will be no carbon credit funds sent when the production is done badly.

>
> The alternative today in most of the world is to burn
> the waste outright and in the tropics to abandon the
> field for years.
>

RWL: There are other alternatives. A great project for many of us is/will be to figure out best charcoaling approaches that are non-polluting, and justify the extra efforts of doing other than "to burn the waste outright and in the tropics to abandon the field for years". Thanks for carrying this idea further on your blog. Sorry to not being in support of any form of in-field charcoaling which is polluting. The work of AD Karve is not in that category - but I still hope we can find ways to productively use those valuable pyrolysis gases.

Ron

I certainly am sympathetic to the desire to minimize the out gassing of combustion products into the environment. The best use of a closed combustion oven with a second high temperature (2000 degrees)chamber to swiftly oxidize the initial combustion gases (at 350 to 600 degrees)is the one way we can do this. This will also end up been the final resolution unless we can figure out how use fusion power to do this.

The challenge is to covert tons of stover into bio char with the least amount of immediate consumption of the stover producing the needed heat.

Burning all of it as a low quality fuel simply releases all the carbon back into the atmosphere.

What those ancient Indians have gifted us with is a well proven protocol for soil enhancement and fertility retention that just happens to sequester hundreds of pounds of carbon per acre every year in perpetuity.