Micron Carbon History Note

There has been a lot of conversation over carbon and the effect of particle size. It is clear that most have no appreciation of available surface area to the efficiency of a chemical process. We are all taught our little chemistry with soluble reagents omitting surface effects entirely.

Most people can get their minds around the idea that increased porosity means more surface area. That is a good start. What is poorly understood is that powdered carbon that can be derived from charring plant material can be presenting surface area orders of magnitude greater than that of wood char that retains a lot of its integrity.

My own experience with this is derived from work done in 1993 with some businessmen, who had contracted with a physicist who had worked in the area of artificial blood. They created a stable suspension of carbon by heating wood at a high temperature and running the resulting gases over a water surface. Gases and powdered carbon were absorbed into the water. A wait period served to allow the lights to remain on top while the heavies settled out. The active and stable center portion was drawn of. The particle size ran to a micron or less and was likely predominantly nano carbon particles. This made me conscious of the real potential of working with various products whose particle size approached this size distribution.

One of the first things that we learned was that a drop of this fluid nicely converted raw whiskey into a fine well aged quality whiskey. It also when sprayed on raw fish added ten days to refrigerator shelf life. In our case we were using it to create micro droplets of hyroluronic acid. The carbon was potent enough to grab the large acid molecules and wrap them up to form a droplet. At least that is what I think happened. We generated a stable suspension of micron sized droplets that acheived superior delivery to the skin surface. Methods such as this are very much in evidence today.

In this brave new world size is all important. Therefore it is no stretch at all to imagine powdered carbon collecting nutrients in a soil and holding them until a stronger biological agent comes along and removes it.

Therefore the best strategy for the manufacture of terra preta surely must involve the charcoaling of plant material lacking structural integrity. Corn, with its lack of woody material and annual nature and huge volume thus becomes an ideal feedstock.

It should also mean that it will take much less effort to create a productive soil if we are able to use such fine carbon powders produced without grinding.

Terra Mulata

Reading through the recent postings I came across a mention of Terra Mulata for the first time. It is associated as a secondary soil to the now becoming recognized Terra Preta soils. I do not assume that this is a particularly recent coinage, but it will surely now be used in conjunction with Terra Preta in scholarly papers. The attached abstract defines both terms and their apparent usage rather well.

This resolves an issue that was bothering me from the beginning and I think is now totally clarified.

It was obvious that a full blown Terra preta soil developed over decades, if not centuries and entailed a lot of ongoing effort every year. Yet it was also obvious that even one year’s effort gave you a productive soil to work with. Now we have a clear resolution of this problem.

Terra preta was solely associated with the settlement site itself where we could expect each family to sustain a hectare of land. The use of an ad hoc earthen kiln would convert a season’s supply of plant waste and cultural waste into a mound of soil and biochar. The clay shards were likely there only because of breakage. Human waste and the like were likely buried in the general waste tip. Every season, this tip was packed down and covered first with a layer of palm fronds to keep the final layer of soil from initially smothering the burn. This was then fired to produce a load of soil and char. This enhanced soil was then carried to the seed hills.

When we come to Terra Mulata we have a slightly different story. We are now dealing with exterior fields that were producing large crops likely to support the state itself (taxes and trade inventory). Corn is a great way to pay your taxes and a great way to store a surplus for much later expenditure and is thus a great example of what is possible.

In this case, they only put in enough char to preserve the soil fertility. There are also no cultural artifacts such as clay shards eliminating the hypothesis that the shards had anything to do with the manufacture of Terra Preta.

The abstract shows that the agricultural culture was very well managed with the existence of large field monocultures not unlike today. You must appreciate that this existed when the only source of energy was man himself. The rise of large field farming in Europe at least had oxen and horses to support it. The diversity of crops is also a surprise. Where were the markets?

We are slowly overcoming the centuries of scholarly dismissal of this culture’s wonderful achievements and are now learning from their achievement.

An earthen corn kiln likely works just fine without the special use of wet clay. And it is very clear that all our tropical soils can be converted to Terra Mulata within a much shorter time frame than expected and does not really need to done too often after initially established.

Going through the numbers again for the corn kiln in particular we have the following;
A given acre of land is cleared by fire. The three sisters are planted in seed hills occupying about twenty five percent of the land. The three sisters consists of corn, legumes for beans and nitrogen fixing and the odd squash to provide soil cover, lowering weed problems and partially protecting the soil from rain erosion.

At the end of season, the dehydrated corn stalks are pulled and used to produce an earthen kiln. There is about ten tons of stover per acre. This will reduce to a little less than two tons of char and admixed soils. Once done, the soil char mix is carried in baskets back to the seed hills.

Eventually the build up of charcoal will naturally migrate into the surrounding soils through any tillage done for other crop types.



Terra Preta and Terra Mulata in Tapajônia: A Subsidy from Culture
Joseph M. McCann

Abstract. The large, multi-ethnic chieftaincy centered on Santarém, Brazil disappeared rapidly in the face of early European slave raids and subsequent missionization, but its physical legacy persists. Ornate ceramics, bamboo forests, relic crops, roads, wells, and manmade waterways in association with patches of anthropogenic dark earth corroborate 17th century chroniclers’ depictions of settled farmers. The evidence suggests the people of Tapajônia lived in permanent settlements and practiced intensive agriculture; they extended the ranges of useful plants, established plantations of fruit-bearing trees, and enhanced soil fertility through inputs of ash, organic mulch and household wastes, creating two kinds of persistently fertile dark earths, the classic terra preta formed under settlements and the somewhat lighter, less chemically enriched terra mulata of agricultural contexts.

Patches of terra preta and terra mulata range from less than 1 ha to more than 100 ha, and are abundantly distributed throughout the region. The spatial distribution and landscape orientation of dark earth patches do not appear to significantly favor varzea or other riverine locations including bluffs, and the largest expanses are located in interior settings. This pattern does not fit the expectations of existing models of Amazonian settlement and subsistence. Rather, it suggests a strategy for optimizing access to a wide range of important resources within a complex landscape mosaic. In addition to inherent ecological factors, the choice of settlement and field locations may have been influenced by access to trade and kinship networks, vulnerability to attack, seasonal transhumance strategies, and cumulative anthropogenic modifications of the landscape.

These modifications, including the enhancement of soil fertility and concentration of useful species and crop germplasm, continue to benefit today’s caboclos, in contrast to most recent development in Amazonia (e.g. mining, ranching, logging). As such, they are an important subsidy from an "extinct" culture. However, access to dark earth is limited by population growth and changing land tenure systems, and the techniques (such as applying mulch and ash, and inoculation with microbiota) which led to their creation are no longer practiced by today’s shifting cultivators. Furthermore, the cultivation of dark earths destroys archaeological artifacts and stratigraphic context that could shed much light on these practices. Clearly, further study of the processes of creation and persistence of Amazonian dark earths are warranted, so that they may serve as models for the development of high-yield, land intensive, yet sustainable land management strategies in the tropics.

J. McCann, Department of Social Sciences, New School University, New York, NY 10011. Email: arapiuns1@msn.com; mccannj@newschool.edu

New Model Farm Update

New Model Farm Update

After a year of writing this column, it is timely to revisit and update the conceptualization of the new model farm. What have we added to our bag of tools and how can we deploy this throughout the globe?

1 Forest management and optimization will now be fully and economically integrated into farm management because cellulose and lignin harvesting is now becoming possible. Wood chips can be sold at the farm gate rather than presenting a disposal cost or simply been burned. This can be applied from the Arctic tree line to the Amazon Jungle. The lignin is a direct source of gasoline and diesel fuels, while the cellulose is becoming a source of ethanol.

2 Shallow wet lands can become growing pads of cattails again over a range that includes at least the boreal forests and the southern jungles. This crop easily produces around thirty dry tons per acre (150 tons wet) of starch rich root material that again is a good feedstock for ethanol as well as producing product for human consumption.

3 The advent of the first two promotes the optimization of both tree based products and wetland products not easily exploited otherwise.

4 Many additional forms of animal and fish husbandry can also be easily implemented with this expansion of boots on the ground. As simple as bison in the eastern woodlands combined with tight management of venison becomes a very good agrobusiness. And we have barely begun to find ways to produce fish in wetlands.

In fact the energy demands of agriculture alone will drive this agricultural revolution. That we can supply the fuel for long haul travel is a natural outcome of this and a secure method to provide sustainable supply.

I for one never imagined that the boreal forest would ever have any commercial value for agriculture. Now we can imagine cattails and wood chips and even a little moose and caribou husbandry on top of various fish production scenarios. And let us not forget beaver husbandry with which I was intimately involved back in the early eighties.

5 Biochar production from plant wastes and corn in particular because of its sheer volume will be applied to soils globally. This will mange nutrient availability and sustain soil fertility, as well as reconstituting all soils as fertile terra pretas. The only remaining restraint will be the availability of water.

Again I never imagined that it might be possible to manufacture soil. Yet this appears possible. You can take a patch of desert sand and create seed hills of sand mixed with biochar. You then plant corn and legumes and squash in the seed hill and add sufficient water. Use the corn stover to produce more biochar and repeat. Five years of this will establish the soil and another generation will have a splendid bulked out humus rich soil inches thick. This can be all be done without any tools other than a hoe, a shovel and a basket.

6 Cheap nanosolar power will permit atmospheric water harvesting. This opens the door for the recovery of deserts everywhere.

In time, the restoration of the deserts will increase the temperature of the northern hemisphere and produce a much more temperate climate. The arctic will be open for navigation. Global agricultural productivity will respond by rising as these global terraforming efforts go to completion.

In fact it is now possible to imagine every acre of land between the Arctic circles feeling the hand of human husbandry. Even wild woods set aside for conservation can benefit from the harvesting of debris to manage forest fire destruction. It should thus be clear that the earth can sustain and feed populations massively larger than we have ever thought possible. Ten billion is a gimme and only a hundred billion seems rather extreme.

But what is our footprint? With terra preta, most nutrients are readily recycled and even built up in the soils. The expansion of such soils is strictly a function of water production into every available nook and cranny possible. Energy is produced by solar conversion and sustainable harvesting methods. We can have all we want.

Our only limit is in fact the land surface of the earth and its maximum production capacity. With a gross surface area approaching 150,000,000 square kilometers of which we can easily disregard a third, we have access to 100,000,000 square kilometers or ten billion hectares. If we assume that a hectare can support a family, a population of around fifty billion is not too far fetched. By then we should be finding other limits.

The possibility of a zero footprint is now very real. Therefore this population is possible and space colonies become possible two seconds after we invent a continuous one G thruster allowing us to move freely. We now know how to live there, without importing anything once established.

And as I have posted earlier, the probability is no longer zero that the ancestral races of mankind have already done this around fifteen thousands of years ago. I now have way too much conforming evidence. We are merely the smucks left with the nasty job of completing the terraforming process. I suspect that I will have to grind out a book on this subject to properly make the case. To me it is now rather obvious. I just need to organize a publisher.

Politics of CO2

The last two years in particular has seen the steady rise of political pressure in the developed world to progressively reduce CO2 emissions. It is reaching the point were decisions are pending that will cause the economy to shift a great deal of its resources. A good part of this shift was inevitable in view of the advent of peak oil supply market behavior. After all, we have gone from a perennial surplus position to a clearly perennial shortfall situation. The working price range has tripled and is now choking demand and forcing the development of alternatives. True global energy security is gone.

There is plenty of merit in weaning ourselves from the hydrocarbon based energy system as the current price regime makes very clear. The first comments have come out suggesting that this price shock will be worse than that of the seventies. This is regrettably very possible. The economic reality that we are all just beginning to wrestle with is that oil has actually priced itself out of the market. Current levels will force a rapid shift in hardware and behavior and a fair bit of hardship. A price move to $300 will actually shut down economic activity which is an unwanted consequence.

What can make this crisis far worse is a decline in deliveries due to loss of production. Right now the new price regime, which I think is already maxed out, is forcing demand to be curtailed directly freeing up production and in the process rebuilding reserves. This process has only begun. We need $100 oil and the world awash in oil to restore some level of confidence. We can survive that. At twice the price, we are looking at a global economic depression sparing no one.

This makes direct interference in the CO2 end of the business terribly ill timed and actually inappropriate. Everyone in the world is now working at reducing their oil footprint as fast as possible. It hardly needs a push and such steps can be very damaging.

We already know that several strategies now exist to comfortably get us out of the oil business and onto a sustainable protocol. Just read my many posts on the various options. Ethanol from cattail farming is a gimme and the advent of printed solar cells will produce a distributed peak energy supply for transport very soon. Both will be very price competitive.

What I find frustrating is that the current scenario was clearly developing and was certainly obvious to astute observers even several years ago. In fact I personally predicted that the price shift would arrive during the last year of the current president’s term of office. And I was hardly an insider. The industry has known that this day was unavoidable, but they had no answers either. The result has been that no preparation was promoted except a little silliness over corn ethanol.

We now have to move our economy on a dime to avoid the worst effects.

So what about CO2? The argument that CO2 is the causation of the very real phenomena of global warming is likely very misplaced. The science itself has been forcefully challenged and is difficult to actually prove anyway. A warming climate is certainly not a proof. We have a soft theory made up to support the facts on the ground that appears to be independent. Just the temperature experience that we have uncovered for the whole of the Holocene tells us that we had better be a lot better prepared before we attempt to link CO2 levels to apparent global temperatures.

The global economy is now beginning a transition over to an energy regime that will eschew fossil fuels, just as we transitioned out of using wood for fuel. It will not take very long and will be largely done in the next two generations.

That then leaves us with the question of what to do with the surplus CO2 in the atmosphere. Once we stop adding to the inventory, just letting nature take its course is a very viable option. It will surely take centuries but we can expect a steady increase in biomass to offset the surplus CO2.

I personally see a far better answer for humanity. Without question, the addition of elemental carbon to all our soils promotes a vast increase in general fertility and general soil nutrient stability. The argument is also made that is also promotes a sharp increase in biological activity that sometimes releases carbon. It is still easily fixed by the expedient of adding a major surplus of carbon as exists in the original terra preta soils.

It can be easily accomplished using both primitive methods and now with solid technological means.

The one other thing that we need to do is to completely revegetate the Sahara and the Sahel. This is a tall order that is best done over a couple of centuries. The remaining deserts can also be so converted provided we are able to tap atmospheric water. The huge benefit of this is to capture a huge amount of heat and moisture in the northern hemisphere now lost to desert heat as well as all the carbon we ever produced.

The hemisphere will become even more suitable for agriculture and we may even make the boreal forest partially productive for agriculture.

The problem we all face is how to guide the political drive to rein in the CO2 production problem into beneficial protocols such as I have described. The technical problem is thought daunting and my proffered solutions are also thought daunting. That means that most minds simply cannot comprehend the actual scale of what they want. Yet I think that it can all be done be the simple expedient of modestly empowering and educating every individual agriculturist on the globe. We only have to recall the organizational achievement of micro finance by Muhammad Yunis.

Industrial Carbon for making Terra Preta

I set out in this article to address the industrial production of carbon for agriculture. I am treating it as an industrial process in order to establish the most cost effective way of getting the task done. The reason that I do this is that is that will always be the prime competition for other industrial methods. We have already done this for the subsistence economies were we applied onsite earthen kilns using the unique nature of corn culture.

I am not constraining myself to sustainable methods for this article, although I certainly think that all agricultural carbon should be made from agricultural waste where possible. It will not be possible for a large portion of the earth’s croplands simply because biomass production is way too low for it to be feasible. If you cannot grow corn for lack of moisture, then you surely cannot make an earthen kiln or even hope to gather enough biomass to make a difference. This describes a lot of good farm land in Africa, to say nothing of the grain lands of western America and Australia.

I also think that the principal benefit of terra preta soils is totally a function of the elemental carbon, rather than any other carbon form. This is because of the long lasting fertility to this day, of terra preta soils, centuries after any other carbon compound was destroyed. It is unlikely that any other factor matters.

So let us stop dragging vast amounts of wet wood waste out of the forest in monster convoys of trucks to the central processing plant. We start instead with bituminous coal. This coal does not even have to be the highest quality because a good chaser of shale may even be a good thing. That also means that huge reserves of poorer quality coal can be exploited. There is plenty of that to do the whole job once and for all.

The coal is then coked in coking ovens which are fueled by process gases and produces a highly porous product of virtually pure elemental carbon. This then has to be crushed into a finely powdered form for agricultural use. It makes very good sense to also blend in fertilizers during this powdering stage. If we are fortunate it should produce a possible non corrosive product that does not damage equipment. At least that should be the objective.

It may prove better to pregrind the coal before it is roasted for forty eight hours. This form of carbon has high crushing strength and this must mean a high wear rate on the grinding equipment. It makes one appreciate the elegance of reducing corn stover to elemental carbon which must naturally produce a finely subdivided powder.

We now have an agriculture ready product that can follow current fertilizer distribution channels.

There is no need to attempt to match terra preta in a single year obviously, but even putting in five hundred pounds per acre, will easily get us there in three generations. Integrating properly with the fertilizer industry facilitates the whole process and allows a slow transition for the soils. Even a hundred pounds per acre as part of the fertilizer blend will put a ton per acre into the ground every twenty years.

Field experiments will need to be done, if only for safeties’ sake. We all know, thanks to the Amazon that the end product is fantastic. However, a hundred pounds even of completely activated charcoal may be simply too aggressively reactive to easily be accommodated.

This or a similar low level can then be even mandated by regulation without putting the industry out of sorts and assuring that soil futility will henceforth be improving no matter how incompetent the individual farm.

This would establish pricing benchmarks that a wood waste charcoal industry must work towards in terms of their feasibility. Biochar kilns on the farm should still produce a better product, but the commercial carbon fertilizer industry can establish a price point for farm labor input.

What I have just described could be implemented today with very little fuss. Experience only has to be gained in grinding coke and blending the various forms of fertilizers to see what is quickly practical.

I want very much to convert atmospheric CO2 into soil carbon by way of carbonizing agricultural waste and thus resolving the CO2 issue. That desire is however equal to the desire to do everything possible to hasten the evolution of global agriculture to sustaining highly fertile soils everywhere and reversing the massive destruction of good farmland everywhere. I even suspect that the soils of the Fertile Crescent can be brought back to ancient fertility and perhaps even reversing the salinity problem there.

The damage done by ten thousand years of often lousy agricultural practice is a problem that puts the current damage of pollution and industrial practice in the shade. We are actually doing a better job as we have industrialized agriculture over the last two generations.

A really great and overly ambitious experiment would be to take a barren field no longer productive because of salinity and attempt an irrigated crop using a ton of carbon fertilizer. It should not work at all, but changes with adjacent untreated plots should inform us if we are onto something. I am optimistic that at some point we will be able to actually produce sweet soil.

Most importantly, the conversion of the industrial fertilizer industry over to carbon based application protocol will assert the primacy of terra preta style soils everywhere and greatly facilitate the adoption of other protocols achieving the same objective.

Milpa and Earthen Kilns

Kevin has done an excellent commentary on the Earthen Kiln Conjecture which I also posted over on the terra preta forum. It has made the whole rather lengthy but sometimes that can not be helped.

He integrates his knowledge of Milpa agriculture which is the three sisters transposed into the tropics. It seemed likely that this was so and it is nice to see it confirmed. I had heard of the Milpa system before but had not quite connected it to the Amazon and even Belize. It almost certainly is the precursor to terra preta.

The evidence suggests that terra preta production was ongoing, yet I am conscious that this was not necessary. Carbon sequestration at the one ton per acre per year rate would produce a base carbon content wildly beyond what was necessary.

Kevin’s remarks are in italics. Any additional remarks of mine will be bold.

Dear Robert
Robert Klein wrote:

I am reposting to my blog http://globalwarming-arclein.blogspot.com/ this article by David Bennet with Lehmann on Terra Preta in2005. This reconfirms the most critical information as well as describes the original scope of the Indian civilization itself. Again this lays out the limiting factors and fully supports my earthen kiln conjecture.

I like your Earth Kiln Conjecture, in that it sets out a possible explanation for the presence of charcoal in TP areas.

Firstly, the maize or corn exists in an environment that mitigated against its use for purely food production. There were alternatives far better suited to the non terra preta environment, starting immediately with manioc which is a rainforest friendly plant.

See: http://www.davidparsons.net/Milpa/M_intro.html, that describes the Milpa System of primitive agriculture as is presently practised in parts of the Yucutan and Belize. Basically, a space is cleared in the jungle, and "The Three Sisters" (Maize, Beans, and Squash) were planted. This system works, and is simple but labor intensive, due to the need to clear new land every year. I would pose that Milpa was the original agriculture system, and that it evolved into the Terra Preta system, that did not require annual clearing of jungle for one crop and then 7 to 20 years of fallow. In summary, the addition of char to a Milpa Plot, would allow addition and retention of additional nutrients, to enhance growth.

I totally agree with this. Any beneficial improvement would be easily observed and copied in this system.

Secondly, the only viable source of meat protein to these peoples at this population density was through fish. Without confirmation, a pond with tilapia makes great sense. The waste from the daily meal could be readily folded into any growing seed hill. Human waste could simply have been buried in the field itself avoiding any storage.

Such a system would make sense in the context of smaller, dispersed villages. The important thing is that large villages and communities start from small villages and communities. Aquaculture was practiced in Chile or Peru, where fish were grown in the irrigation channels in the sides of mountainous terrain, where there was the grade for water conveyance. A key thing was that such "fish water" conveyed both phosphorous and potassium to the plants, in addition to the water. Tilapia are a very special fish, in that they can live on algae. Algae growth can be promoted by addition of manure to the irrigation water, and the Tilapia can grow under "green water conditions", as is employed in SE Asia Pond Culture. In larger communities, the field irrigation channels would provide a very convenient way for disposal of night soil.

I first came across Tilapia in conjunction with the Mayan ditch and bank system of producing rich gardens that was used throughout the Americas from Michigan to Chile.

> This is common practice to this day.

The making of the earthen kiln is no more difficult than uprooting the dehydrated corn stalks and properly stacking them to form an earthen walled kiln with a wall thickness of two to three root pads and an interior of tightly packed cornstalks.

Given that the Primitive Farmer went to all the work of clearing a hole in the Jungle, and given that he had one good year with a bountiful harvest, it would be a natural step to try and avoid the extra work required to clear more Jungle, to continue with the cropping/fallow cycle. It would be a lot easier to pull the maize stalks and stack them as you suggest, to dispose of them in an attempt at getting another year out of a particular Milpa Clearing. The Milpa System employs fire as a "clearing aid", and in the attached photo, charcoal is evident.

http://www.davidparsons.net/Milpa/M_practices.html. Note however, that with the Milpa System, the exposed sticks and stalks would generally burn to completion. However, with Robert's Earthen Kiln Hypothesis, the "root ball walls" would tend to collapse onto the partially burned/charred corn stocks, smothering the fire, preventing it from going to completion, and thereby producing a much higher yield of residual char than would an open bonfire.

It required only one smart farmer to think this up and try it out

Obviously, any other plant material, including wood can be built into the stack as available. The earthen wall nicely restricts air flow during the burn phase and lends itself to optimization by changing the thickness. It also minimizes the amount of human effort needed which is through the roof if you are attempting to cover a pile of stubble or branches. This gives you a kiln with vertical earthen walls and a possibly domed top that can be easily covered with earth. Again, field trials will optimize this protocol very easily. The kiln could be squared of or perhaps even circular though unlikely. The only tool to this point is a strong back or two.

Nowadays, the Milpa Farmers have the benefit of steel machetes, and would be able to easily cut the stalks from the root ball. Without a machette, it would be much easier to pull up the entire stalk, and stack the stalk and root ball in the manner suggested by Robert. Certainly, the incremental effort to pull and stack the stalks would be less than the effort to move to another site and clear more jungle.

> We have gathered several tons of corn stover over perhaps an acre of land with only a little more effort than that required to clear the field and burn the waste. Now we must fire the kiln. The easy way is to take a clay lined old basket and fill it up with coals from a wood fire. Carry this ember charge to the center of the kiln top and tip the charge onto the exposed center and place the basket as a cap to the newly forming chimney.

> More clay may be necessary to widen the chimney cap. Throw more earth on top of
this to prevent breakout of the fire. Keep growing earth on any breakout points that start.
The chimney will serve to burn all the volatiles produced as the hot zone expands to fill the collapsing kiln until they are exhausted.

If the Farmers were simply trying to get rid of vegetative waste, to avoid opening up new Jungle, then they may not have been very interested in plugging up any air leakage points. Less labor would be involved is simply "stack and burn", rather than tending the earthen kiln. They had no need to burn the volatiles to completion. Indeed, the smoke would probably be beneficial, through dispersing mosquitoes and insects.

> There upon the hot zone will cool off leaving a blend of biochar, ash and earth and
ome root ends for the next kiln. And yes, we should have a lot of fired clay.

This is very interesting. Loose earth from the root balls would not be compacted sufficiently to yield the pottery shards we now associate with Terra Preta. However, the process could very well have produced "microshards" of "pottery". Actually, this "fired soil" would not be "microshards", in that the term "shard" usually refers to "broken pieces of pottery", and it would not be "pottery", in that the term usually refers to "a formed clay shape that was fired to enhance its properties." It would be expected that this would be a "low temperature firing", and it is thus not likely that the "fired root ball pottery particles" would be able to endure the ravages of 500 to 4,000 years of tropical weathering.

I would actually be surprised to see any firing taking place in the soils themselves. However, the thin clay plate sitting on top of the chimney preventing a full burn out would get hot enough to fire. Of course, they may simply have fired sun dried plates elsewhere, but so far I have seen no evidence of such kilns.

> The biochar itself will be a range of nonvolatile combustion products that will range from even dried vegetation to activated charcoal following a nice bell curve. The material can be then gathered in baskets and redistributed into the field onto the seed hills again reducing wastage and effort. I realized originally that the only ancient plant that could accommodate a high enough volume of terra preta production was good old maize. It just seemed an unlikely option for tropical rainforests. That is when I started looking for references to the pollen record. The article by David Bennett and Lehmann is one of those references that then emerged. I would like to get a full spectrum of the pollen profile since it seems very likely that while the fence rows held the food trees, it seems more likely that they also used a variation of the three sisters using some form of convenient legume. Squashes also, of course, but not nearly as important. The key point of all this is that a family can convert a field into terra preta in one short season, allowing them to repeat the process thereafter as necessary until the field is completely transformed to depth. Today, we can do the same thing using shovels and a garbage can lid.

Terra preta: unearthing an agricultural goldmine Nov 14, 2005 10:36 AM, By David BennettIn http://www.davidparsons.net/Milpa/M_threats.html, there is reference to "insufficient period of fallow". It would indeed be advantageous to be able to extend the productive period of a Milpa, to avoid the need to clear more jungle. Weeds are a problem in a fertile soil. What they needed for sustained cropping of a given milpa area would be

1: A mulch system, that focused growth where they wanted it, and
2: Plant nutrients.

Now, people don't live in the fields where they are attempting to grow their food crops. They would live adjacent to their fields. They would, of course, be producing Nightsoil, and naturally, they would need to dispose of it. Fresh manure and night soil could

The seed hills occupy twenty five percent of the available space. The night soil can be covered with soil and placed in a new location each time. I saw this recently described in India. (it is only a problem in cold climates were breakdown is postponed.

damage the crops. For the simple reason of smell, it would make sense to have adjacent fields working on "short fallow system"... crop one field area, while applying the humanure to an adjacent area. This would allow pathogens the time to degrade to a safe level. An additional "health protection benefit" of the "Three Sisters" is that they are all "above ground crops."

They had pots made of "pottery", and these pots over time would break. It would not take long for a Farmer to discover that pottery shards make an excellent mulch, in that plants do not grow up through pottery pieces. A further benefit of such pottery mulch is that it is fireproof. It would be a relatively easy thing to simply "burn the weeds". A further benefit using such a "fireproof mulch" is that there would tend to be moisture retention below the shards, and this moisture would tend to prevent loss of organic material from the soil. Fire burning of the weed tops with pottery shards as a "fireproof mulch" would result in an increase of organic material in the soil, from the weed root system.

There is way too much ‘pottery’ to be explained by household breakage. And a clay plate or clay lined basket was clearly necessary to carry an ember charge and cap the resultant chimney. It would shatter in the heat.

> > Many soil scientists insist an ancient Amerindian agrarian society will soon
Ø make a huge impact on the modern world. They say once the intricacies and
Ø > formulation of the society’s “terra preta” (dark earth) is unlocked, the
Ø > benefits will help stop environmental degradation and bring fertility to
Ø > depleted soils. Developing and developed nations will benefit.

Ø > Milpa and Terra Preta were NOT "systems designed to prevent environmental degradation... they were systems designed to provide a supply of wholesome food on a regular and dependable basis. Certainly, obvious signs of "environmental degradation" would be dealt with, and the one concern I could see that they would have is loss of soil through erosion. Flat pottery shards would absorb the energy of falling rain, and reduce soil erosion problems.

> Orellana
>>> The story goes that in 1542, while exploring the Amazon Basin near Ecuador
> in search of El Dorado, Spanish conquistador Francisco de Orellana began
> checking the area around one of the Amazon’s largest rivers, the Rio Negro.
> While he never found the legendary City of Gold, upon his return to Spain,
> Orellana reported the jungle area held an ancient civilization — a farming
> people, many villages and even massive, walled cities.
>>> Later explorers and missionaries were unable to confirm Orellana’s reports.
> They said the cities weren’t there and only hunter-gatherer tribes roamed the
> jungles. Orellana’s claims were dismissed as myth.
>>> Scientists who later considered Orellana’s claims agreed with the negative
> assessments. The key problem, they said, was large societies need much food,
> something Amazonia’s poor soils are simply incapable of producing. And without
agriculture, large groups of people are unable to escape a nomadic existence,
> much less build cities.

> Milpa could very well progress to Terra Preta, and with the sanitation requirements for larger communities, there could very well have been a food system that evolved to support it. A classic symbiotic relationship.

> Dark earth
>>> More recently, though, Orellana’s supposed myths have evolved into distinct
> possibilities. The key part of the puzzle has to do with terra preta.
> It turns out that vast patches of the mysterious, richly fertile, man-made
> soil can be found throughout Amazonia. Through plot work, researchers claim
> terra preta can increase yields 350 percent over adjacent, nutrient-leached
> soils.

> There is absolutely no mystery or miraculous occurence here... plants grow well in nutrient rich soil and they grow poorly in nutrient poor soil. With all the burning and vegetation, it would be natural for some of the Milpa Farmers to have noticed that black soil seemed to last longer before yields fell off to the point that a fallow period was necessary. These Farmers were primitive, but they weren't stupid.

I completely agree that an association would be made between high carbon content and sustained soil fertility. I made the exact same observation as a child on our farm from what must have been a patch used to burn out a huge amount of wood during the original clearing of the land. It had the thickest and best grass on the farm.

> Many well-respected researchers now say terra preta, most of it still hidden
> under jungle canopy, could have sustained large, agronomic societies throughout Brazil
and neighboring countries.

> The "well respected researchers" don't deserve much respect, if all they can say about Terra Preta is that "... it could have sustained large agronomic societies...". They would deserve much more respect if they provided more insight into Terra Preta. :-) The above statement may have some profound content..."... terra preta, most of it hidden under Jungle canopy..." Is it perhaps possible that terra preta is simply the natural jungle soil?

> Amazing properties
>>> The properties of terra preta are amazing. Even thousands of years after> creation, the soil remains fertile without need for any added fertilizer.

This is a stretch. A very big stretch. It goes against all known "Agricultural Paradigms". Mother Nature is very strict with her rule "You never get something for nothing." The above statement would only be true if a fertile, nutrient laden soil was not used for growing, or if nothing was removed from the site as crops, or through leaching, or as food for soil organisms, or as an oxidation product..

Not so fast – the carbon grabs nutrients and holds them. Only a little is actually used each season. Without terra preta the remaining nutrients are washed away. With terra preta any fresh waste nutrients are recaptured and also made available. Thus it is no surprise that reports of sixty years without fertilization are heard. Our own system is incredibly wasteful, distorting our expectations.

> For those living in Amazonia, terra preta is increasingly sought out as a
> commodity. Truckloads of the dark earth are often carted off and sold like
> potting soil.
> Certainly, there are people who make their living all over the world bringing in topsoil, compost, and manure to areas where the soil is deficient in organic matter and nutrients.

> Chock-full of charcoal, the soil is often several meters deep. It holds
> nutrients extremely well and seems to contain a microbial mix especially suited
> to agriculture.
> Certainly, this would work. Note, however, that black soil found in a wet depression could very well have been formed naturally, without the presence of man-made charcoal. The soils are referred to a "Black Carbon" soils, and "black carbon" can occur naturally through decomposition of organic matter in anaerobic conditions.
> Thus far, despite great effort, scientists have been unable to duplicate
> production of the soil. If researchers can ever uncover the Amerindians’ terra
> preta cocktail recipe, it will help stop the environmentally devastating
> practice of slash-and-burn agriculture in the Amazon jungle. Terra preta’s
> benefits will also be exported across the globe.

> The above passage reads well, but it doesn't say much about the caliber of scientific effort being directed at figuring out how to "reverse engineer" Terra Preta!! :-)

> However, even without unlocking all of the soil’s secrets, things learned in
> the study of it are already being brought to row-crop fields.
> Among researchers studying terra preta is Johannes Lehmann, a soil
fertility management expert and soil biogeochemistry professor at Cornell
university. Lehmann, who recently spoke with Delta Farm Press, says things learned
from terra preta will help farmers with agricultural run-off, sustained fertility and input
costs. Among his comments:
>>> On how Lehmann came to terra preta research…
>>> “I spent three years living and working in degraded Amazonia field sites.
> Inevitably, if you work in the central Amazon, you come across terra preta.
> “The visual impact of these soils is amazing. Usually, the soils there are
> yellow-whitish colored with very little humus. But the terra preta is often 1
> or 2 meters deep with rich, dark color. It’s unmistakable. We know terra preta
> are preferentially cropped.”
>>> On the various properties of terra preta and its modes of action…
>>> “There are a few factors that contribute to this fertility — sustainable fertility.
> Remember, these are soils that were created 1,000 to 5,000 years ago and were
> abandoned hundreds or thousands of years ago. Yet, over all those hundreds of
> years, the soils retain their high fertility in an environment with high
> decomposition, humidity and temperatures. In this environment, according to
> text books, this soil shouldn’t exist.
>>> “That alone is fascinating for us.

> Amazonian Jungles have been in existence for much longer than the presence of Man in Amazonia. They are a natural phenomenon. They work as a result of the layer of humus on the surface of the jungle floor that captures available nutrients and releases them to jungle vegetation. An abandoned Terra Preta plot could be expected to remain fertile for a very long time, PROVIDING THAT no crops were removed from the site.

Except this is in contrast with the rapid fertility loss of all tropical soils because of the rapid movement of rainwater deep into the soils

>> “Among the most important properties are high nutrient concentrations
> (especially for calcium and phosphorus). Most likely, this is linked to a
> unique utilization of agricultural and fishery waste products.

> Certainly, one would expect higher levels of soil nutrition in the vicinity of human habitation, where they had a nightsoil and food waste resource that was at the same time, a disposal problem and a tremendous agricultural resource.

>> “We believe that fish residues are an important portion of the high
> phosphorus concentrations. Phosphorus is really the number one limiting
> nutrient in the central Amazon.

> Near River/Lake systems, natural fish could provide a good source of protein, and fish bones for fertilizer. Pond Culture may have been employed further away from rivers and lakes. Human and animal manures resulting from "new phosphorous" being brought into the area as a result of the people "importing" foods from outside the community would also result in an "above average phos level.

Also terra preta does not let the unused phosphorus to escape.
>> “Another interesting aspect of terra preta’s high fertility is the char
> (charcoal) content of the soil. This was deliberately put into the soil by the
> Indians and doesn’t only create a higher organic matter — and therefore higher
> fertility through better nutrient-retention capacity — but this special type of
> carbon is more efficient in creating these properties.
>>> “You can have the same amount of carbon in terra preta and adjacent soils
> and the infertile soil won’t change. Terra preta’s abilities don’t just rely on
> more carbon, but the fact that its char and humus is somehow more efficient in
> creating beneficial properties. That’s the truly unique aspect.”

> This is very interesting. He might be differentiating between "Black Carbon Soils" that contain "pyrocarbon" and those that only contain "natural black carbon." It is also possible that on the "poor" Black Carbon Soil plots, the Cation Exchange Sites on the charcoal and natural black carbon may be occupied by cations that were not beneficial to the plants, and thus unable to hold the nutrients that were the "bottleneck to growth."

> Having lived in the Amazon and studied it, how much terra preta does
> Lehmann believe there is?
>>> “There are no precise numbers of how much terra preta there is (in
> Amazonia). No one has done any large-scale investigation of that. It’s very
> difficult to find out in the Amazon’s jungle environment. Suitable
> remote-sensing techniques haven’t yet been used.
>>> “So (the 10 percent) estimates sometimes cited are crude extrapolations from
> the few areas we’re familiar with. But we know that in familiar areas there are
> huge patches of terra preta. These are hundreds of hectares large. When there
> have been maps produced of areas containing terra preta — say an area around a
> stream — patches are everywhere.
>>> “It is also true that terra preta is widespread. Almost anywhere in the
> central Amazon, you can step out of the car and ask a local ‘Is there any terra
> preta around?’ and they’ll show you. It’s everywhere.”
>

Effort should be made to determine if these Black Carbon Soils were the initial result of natural black carbon formation, and if the Anthropogenic contribution of charcoal to Black Carbon Soils was an incidental result of working a natural black carbon soil.

>> What were the Indians growing? Tree crops? Row crops?
>>> “There has been some pollen analysis. It suggests manioc and maize were
> being grown 2,000 to 3,000 years ago. In the pollen bank, these crops didn’t
> pop up sporadically but in large numbers.
>>> “But all kinds of crops were grown by the Indians. Palm trees,
> under-story fruit trees, Brazil nut trees — all were very important.”
>>> On the differences between slash-and-burn and slash-and-char agriculture…
>>> “We have very good indications that the Amerindian populations couldn’t have
> practiced slash-and-burn and created these soils.

> This statement should be clarified. There is indeed very good evidence that the Mayans in the Yucatan have indeed been practising "slash and burn" agriculture on a sustainable basis for thousands of years. Milpa is "slash and burn" on a patchwork basis.

>> “It’s also highly unlikely that a population relying on stone axes would
> have practiced slash-and-burn anyway. The normal soils are so poor that with a
> single slash-and-burn event, you can only crop without fertilizer for two years
> at most. Then the soil has to be left fallow again.

> Yes, that is what the Mayans found also. This is where the addition of Humanure could have led to sustained "single site tropical agriculture." Additional nutrients would give immediate feedback to the Farmer, and would encourage him to do it again next season"

>> “Primary forest trees have a diameter of 2 or 3 meters. If all you had was a
> stone ax in your hand, you’d find a different way to deal with agriculture than
> felling these huge trees every two years.

> Huge trees take a long time to grow, especially in nutrient poor soils. The cycle time of cropping a Milpa Site is about 7 to 20 years; replacement trees would be nowhere as large as 2 to 3 meters in diameter. Note that such large trees can be easily taken down by primitive technology.... simply chop or burn the anchor roots and wait for the first good windstorm. When the tree fell, it could be disposed of by burning. These tree stems and branches could have been a significant source of charcoal for the site.

The easiest way was to simply girdle all the trees and come back in a couple of years. The voracious climate would be quickly reducing the remaining material.

>> “The difference between (the two systems) is the slash-and-char wouldn’t
> burn in an open fire. Charcoal would be produced under partial exclusion of
> oxygen. We envision that happening by natives covering up piled up logs with
> dirt and straw. These charcoal-making systems are still being used around the
> world.”

In the photo referenced above, there is clear evidence of charcoal having been produced, and there is no evidence of effort been expended to prevent total burning of the wood.

>> How close are researchers to duplicating terra preta?
>>> “We’re working intensively. We don’t need to take any terra preta anywhere.
> What we want to do is become knowledgeable about how terra preta was created
> and then create it elsewhere with local resources.
>>> “Research on this is ongoing in Columbia, in Kenya. I have research
> colleagues in Japan and Indonesia also working on this. At the moment, there is
> a lot of excitement but there’s a lot of work to do.”
> It would indeed be interesting to know the avenues being pursued by the various researchers.

>> How terra preta could help industrialized countries…
>>> “We envision systems based on some of the principles of terra preta. And
> this isn’t just for tropical agriculture. This could be very important for U.S.
> agriculture.
>>> “Terra Preta could mean a reduction in environmental pollution. What works
> as a retaining mechanism in Amazonia could work in the United States where
> there are concerns of phosphates and nitrates entering groundwater and streams.
> We have only begun to realize the potential of how this could reduce pollution
> in industrialized countries.

> "Pollution in industrial Countries" was not a concern of the Amazonians. Having a fertile soil and a secure food supply was a concern. Segregating Municipal Sewage from toxic Industrial Waste should allow safer and more widespread application of Municipal Sewage into agricultural systems, reducing such sewage pollution

>> “Luckily the principles of creating bio-char soils will be very similar no
> matter what area of the world you’re in. Results obtained in Brazil will be
> pertinent for the United States.
> One should be careful here. There are many very fertile "Black Soils" throughout the world that have "Natural Black Carbon", and where there is no "bio-char" that was made by a pyro process.

>> “In terms of widespread adoption, it’s still some way away. There are still
> knowledge gaps. For instance, we know there are important differences in the
> effects of bio-char on soil fertility depending on what material you use and
> what temperature and under what conditions the char is produced. That’s
> something we should be able to resolve within a year or two. Once that’s done,
> we can take the systems to Extension Services around the world and make larger
> scale, on-farm research plots.
>

Fertilizer additions seem to be an important part of the research work. Little is said about the importance of fertilizers and nutrients, the emphasis is primarily on the "bio-char", with little apparent recognition of the importance of "natural black carbon" in the soils.

Best wishes

Kevin

Earthen Terra Preta Kilns and Pollen Spectrum

I am reposting this article by David Bennet with Lehmann on Terra Preta in 2005. This reconfirms the most critical information as well as describes the original scope of the Amazonian Indian civilization itself.

Again this lays out the limiting factors and fully supports my earthen kiln conjecture.

Firstly, the maize or corn exists in an environment that mitigated against its use for purely food production. There were alternatives far better suited to the non terra preta environment, starting immediately with manioc which is a rainforest friendly plant.

Secondly, the only viable source of meat protein to these peoples at this population density was fish. Without confirmation, a pond with tilapia makes great sense. The waste from the daily meal could be readily folded into any growing seed hill. Human waste could simply have been buried in the field itself avoiding any storage. This is common practice to this day.

The making of the earthen kiln is no more difficult than uprooting the dehydrated corn stalks and properly stacking them to form an earthen walled kiln with a wall thickness of two to three root pads and an interior of tightly packed corn stalks. Obviously, any other plant material, including wood can be built into the stack as available. The earthen wall nicely restricts air flow during the burn phase and lends itself to optimization by changing the thickness. It also minimizes the amount of human effort needed which is through the roof if you are attempting to cover a pile of stubble or branches.

This gives you a kiln with vertical earthen walls and a possibly domed top that can be easily covered with earth. Again, field trials will optimize this protocol very easily. The kiln could be squared of or perhaps even circular though unlikely. The only tool to this point is a strong back or two. We have gathered several tons of corn stover over perhaps an acre of land with only a little more effort than that required to clear the field and burn the waste.

Now we must fire the kiln. The easy way is to take a clay lined old basket and fill it up with coals from a wood fire. Carry this ember charge to the center of the kiln top and tip the charge onto the exposed center and place the basket as a cap to the newly forming chimney. More clay may be necessary to widen the chimney cap. Throw more earth on top of this to prevent breakout of the fire. Keep growing earth on any breakout points that start. The chimney will serve to burn all the volatiles produced as the hot zone expands to fill the collapsing kiln until they are exhausted. Thereupon the hot zone will cool off leaving a blend of biochar, ash and earth and some root ends for the next kiln. And yes, we should have a lot of fired clay.

The biochar itself will be a range of nonvolatile combustion products that will range from even dried vegetation to activated charcoal following a nice bell curve. The material can be then gathered in baskets and redistributed into the field onto the seed hills again reducing wastage and effort.

I realized originally that the only ancient plant that could accommodate a high enough volume of terra preta production was good old maize. It just seemed an unlikely option for tropical rainforests. That is when I started looking for references to the pollen record. The article by David Bennett and Lehmann is one of those reverences that then emerged.

I would like to get a full spectrum of the pollen profile since it seems very likely that while the fence rows held the food trees, it seems more likely that they also used a variation of the three sisters using some form of convenient legume. Squashes also, of course, but not nearly as important.

The key point of all this is that a family can convert a field into terra preta in one short season, allowing them to repeat the process thereafter as necessary until the field is completely transformed to depth. Today, we can do the same thing using shovels and a garbage can lid.

Terra preta: unearthing an agricultural goldmine

Nov 14, 2005 10:36 AM, By David Bennett

Many soil scientists insist an ancient Amerindian agrarian society will soon make a huge impact on the modern world. They say once the intricacies and formulation of the society’s “terra preta” (dark earth) is unlocked, the benefits will help stop environmental degradation and bring fertility to depleted soils. Developing and developed nations will benefit.

Orellana

The story goes that in 1542, while exploring the Amazon Basin near Ecuador in search of El Dorado, Spanish conquistador Francisco de Orellana began checking the area around one of the Amazon’s largest rivers, the Rio Negro. While he never found the legendary City of Gold, upon his return to Spain, Orellana reported the jungle area held an ancient civilization — a farming people, many villages and even massive, walled cities.

Later explorers and missionaries were unable to confirm Orellana’s reports. They said the cities weren’t there and only hunter-gatherer tribes roamed the jungles. Orellana’s claims were dismissed as myth.

Scientists who later considered Orellana’s claims agreed with the negative assessments. The key problem, they said, was large societies need much food, something Amazonia’s poor soils are simply incapable of producing. And without agriculture, large groups of people are unable to escape a nomadic existence, much less build cities.

Dark earth

More recently, though, Orellana’s supposed myths have evolved into distinct possibilities. The key part of the puzzle has to do with terra preta.

It turns out that vast patches of the mysterious, richly fertile, man-made soil can be found throughout Amazonia. Through plot work, researchers claim terra preta can increase yields 350 percent over adjacent, nutrient-leached soils.

Many well-respected researchers now say terra preta, most of it still hidden under jungle canopy, could have sustained large, agronomic societies throughout Brazil and neighboring countries.

Amazing properties

The properties of terra preta are amazing. Even thousands of years after creation, the soil remains fertile without need for any added fertilizer. For those living in Amazonia, terra preta is increasingly sought out as a commodity. Truckloads of the dark earth are often carted off and sold like potting soil.

Chock-full of charcoal, the soil is often several meters deep. It holds nutrients extremely well and seems to contain a microbial mix especially suited to agriculture.

Thus far, despite great effort, scientists have been unable to duplicate production of the soil. If researchers can ever uncover the Amerindians’ terra preta cocktail recipe, it will help stop the environmentally devastating practice of slash-and-burn agriculture in the Amazon jungle. Terra preta’s benefits will also be exported across the globe.

However, even without unlocking all of the soil’s secrets, things learned in the study of it are already being brought to row-crop fields.

Among researchers studying terra preta is Johannes Lehmann, a soil fertility management expert and soil biogeochemistry professor at Cornell University. Lehmann, who recently spoke with Delta Farm Press, says things learned from terra preta will help farmers with agricultural run-off, sustained fertility and input costs. Among his comments:

On how Lehmann came to terra preta research…

“I spent three years living and working in degraded Amazonia field sites. Inevitably, if you work in the central Amazon, you come across terra preta.

“The visual impact of these soils is amazing. Usually, the soils there are yellow-whitish colored with very little humus. But the terra preta is often 1 or 2 meters deep with rich, dark color. It’s unmistakable. We know terra preta are preferentially cropped.”

On the various properties of terra preta and its modes of action…

“There are a few factors that contribute to this fertility — sustainable fertility. Remember, these are soils that were created 1,000 to 5,000 years ago and were abandoned hundreds or thousands of years ago. Yet, over all those hundreds of years, the soils retain their high fertility in an environment with high decomposition, humidity and temperatures. In this environment, according to text books, this soil shouldn’t exist.

“That alone is fascinating for us.

“Among the most important properties are high nutrient concentrations (especially for calcium and phosphorus). Most likely, this is linked to a unique utilization of agricultural and fishery waste products.

“We believe that fish residues are an important portion of the high phosphorus concentrations. Phosphorus is really the number one limiting nutrient in the central Amazon.

“Another interesting aspect of terra preta’s high fertility is the char (charcoal) content of the soil. This was deliberately put into the soil by the Indians and doesn’t only create a higher organic matter — and therefore higher fertility through better nutrient-retention capacity — but this special type of carbon is more efficient in creating these properties.

“You can have the same amount of carbon in terra preta and adjacent soils and the infertile soil won’t change. Terra preta’s abilities don’t just rely on more carbon, but the fact that its char and humus is somehow more efficient in creating beneficial properties. That’s the truly unique aspect.”

Having lived in the Amazon and studied it, how much terra preta does Lehmann believe there is?

“There are no precise numbers of how much terra preta there is (in Amazonia). No one has done any large-scale investigation of that. It’s very difficult to find out in the Amazon’s jungle environment. Suitable remote-sensing techniques haven’t yet been used.

“So (the 10 percent) estimates sometimes cited are crude extrapolations from the few areas we’re familiar with. But we know that in familiar areas there are huge patches of terra preta. These are hundreds of hectares large. When there have been maps produced of areas containing terra preta — say an area around a stream — patches are everywhere.

“It is also true that terra preta is widespread. Almost anywhere in the central Amazon, you can step out of the car and ask a local ‘Is there any terra preta around?’ and they’ll show you. It’s everywhere.”

What were the Indians growing? Tree crops? Row crops?

“There has been some pollen analysis. It suggests manioc and maize were being grown 2,000 to 3,000 years ago. In the pollen bank, these crops didn’t pop up sporadically but in large numbers.

“But all kinds of crops were grown by the Indians. Palm trees, under-story fruit trees, Brazil nut trees — all were very important.”

On the differences between slash-and-burn and slash-and-char agriculture…

“We have very good indications that the Amerindian populations couldn’t have practiced slash-and-burn and created these soils.

“It’s also highly unlikely that a population relying on stone axes would have practiced slash-and-burn anyway. The normal soils are so poor that with a single slash-and-burn event, you can only crop without fertilizer for two years at most. Then the soil has to be left fallow again.

“Primary forest trees have a diameter of 2 or 3 meters. If all you had was a stone ax in your hand, you’d find a different way to deal with agriculture than felling these huge trees every two years.

“The difference between (the two systems) is the slash-and-char wouldn’t burn in an open fire. Charcoal would be produced under partial exclusion of oxygen. We envision that happening by natives covering up piled up logs with dirt and straw. These charcoal-making systems are still being used around the world.”

How close are researchers to duplicating terra preta?

“We’re working intensively. We don’t need to take any terra preta anywhere. What we want to do is become knowledgeable about how terra preta was created and then create it elsewhere with local resources.

“Research on this is ongoing in Columbia, in Kenya. I have research colleagues in Japan and Indonesia also working on this. At the moment, there is a lot of excitement but there’s a lot of work to do.”

How terra preta could help industrialized countries…

“We envision systems based on some of the principles of terra preta. And this isn’t just for tropical agriculture. This could be very important for U.S. agriculture.

“Terra Preta could mean a reduction in environmental pollution. What works as a retaining mechanism in Amazonia could work in the United States where there are concerns of phosphates and nitrates entering groundwater and streams. We have only begun to realize the potential of how this could reduce pollution in industrialized countries.

“Luckily the principles of creating bio-char soils will be very similar no matter what area of the world you’re in. Results obtained in Brazil will be pertinent for the United States.

“In terms of widespread adoption, it’s still some way away. There are still knowledge gaps. For instance, we know there are important differences in the effects of bio-char on soil fertility depending on what material you use and what temperature and under what conditions the char is produced. That’s something we should be able to resolve within a year or two. Once that’s done, we can take the systems to Extension Services around the world and make larger scale, on-farm research plots.

“We’re already working with dozens of Kenyan farmers on this. The project only began this year. By next year, we hope to have a better idea of how this works on farms.”

Where will the bio-char come from?

“Perhaps agricultural and forestry waste products could be the answer.

“Something else that gets us very excited is a link to energy production systems (utilizing) pyrolysis...

“Really, pyrolysis is a just a complicated word for making charcoal. Prototypes of this system for commercial power plants have been developed. These create bio-oil, hydrogen and other co-products — including bio-char — from the production of charcoal.

“We want to gain a better understanding of what effects this bio-char has on soil functions. It should be quite similar to a bio-char produced in a kiln or field. Such a system will be an entry point for large-scale production and use.

“There are competing uses for the power plant byproducts. Currently, power plants either use the byproducts for their own energy needs or they sell it to be used as charcoal briquettes.

“It could become profitable as soon as some of the environmental effects — currently external — are internalized. For instance, cleaner streams, cleaner groundwater, carbon sequestration and other things.”

For more information, visit www.css.cornell.edu/faculty/lehmann/terra_preta/TerraPretahome.htm

Global Food Shortfall

I see the press is warming up to the reality of rising food prices around the globe. I myself glanced at the price of wheat for the first time in months this morning and was shocked to see price quotes in the teens for a bushel. forty bushels per acre now translates into a gross of $400 per acre for productive farmland. A couple of hundred acres under cultivation translates into a check for $80,000 at the farm gate. That is way over twice what anyone has experienced over the years.

The fact is that reserves are low and now also vulnerable. Of course the heavy snow this winter should presage a bumper crop and you may be sure every available acre will be able to come under cultivation with all that moisture in the fields. Globally, it still looks tight and we need stocks to be rebuilt. Several good years of high prices will hugely recapitalize the farm industry and sharply increase production, so I am really not concerned.

What I want to see is the rapid implementation of terra preta soil culture throughout the world as fast as possible and not just because it sequesters carbon. I have shown two methods of producing high volume bio char in either an earthen kiln in the subsistence economy or a shipping container system in the developed economy. This soil culture was field tested for hundreds of years in the Amazon and then lost when Eurasian disease arrived after Columbus. This is an incredibly important fact that seems lost on most commentators.

On soils that will not hold their fertility and thus today carry only a very small population with terra preta supported crops year after year with huge populations of many millions. The sub text of the terra preta carbon sequestration story is the real delivery of a crop soil building technology that is certainly applicable on every other soil that we use and many soils that we currently do not use.

Just going to the tropical hillsides in the Indonesian Archipelago and introducing this method successfully will employ many millions of people. Those verdant hills are currently cropped once every fifteen years using slash and burn. It appears to be trivial to adapt the earthen kiln to that society and agricultural culture.

The land is there almost for the taking and the population can deliver the key ingredient of labour. The earthen kiln protocol is a reconstruction of ancient amazon methods using corn or maize and effectively little more than bare hands and a basket or two. It is time to establish a proper tropical soils homestead act in all these countries to let the people build their new world.

The magic of bio char is derived exclusively from the particular nature of carbon itself. Recall that all non pure carbon components will be consumed by the soil biota. Recall that free nutrients will migrate into the water table if they are not intercepted somehow. Pure carbon, or perhaps better named unbound carbon, forming crystals, will grab these nutrients and hold them until a root or other biological agent removes them. This carbon will also remain in the working layer of the soil. That is why it converts impossible tropical soils into totally usable cropland such as is still used in the Amazon.

I personally have no doubt that this soil revolution is more than sufficient to support many additional billions of mouths. Imagine your most productive soils suddenly becoming available in areas the size of France in a dozen locales. Before terra preta, my imagination hit the wall at around ten billion because of the inhospitable nature of tropical soils. Now the incredible fecundity of the tropics combined with a working tropical soil suggests that global populations of even thirty billion could be possible.

It would be ironic if some day in the not too distant future it became necessary to burn more fossil oil in order to produce enough global CO2 to support the burgeoning populations and their associated high carbon agriculture.

Of course we will not go there, but we will be hugely richer in agricultural resources with the flexibility to crop a region and then abandon it back to the wild as often as we feel is wise. Imagine abandoning most of the headwater regions of the Hudson River for three hundred years. A complete recovery would ensue and planned reentry could then be based on a maximizing model that preserved as well as used.

Johannes Lehmann interview on terra Preta

I came across this recent interview on the net by Matthew Wright with Johannes Lehmann. He is the leading academic voice on the subject of terra preta soils. It presents the current state of work in the area. I continue to be convinced that the earthen kiln method replicated with today’s tools is the quickest way to enter the field trial format. Mechanized solutions have to evolve.

An important open question is to what extent the Amazon Indians used legumes with their corn – cassava culture. It seems likely in view of the corn – bean squash culture of the North Americans.

I would like to see squash properly reintroduced as a staple into our diets. I always knew that they cubed the flesh and dried it out for storage. I have since learned that they also smoked it. This would have real culinary potential which has been lacking.


Drawing down carbon - Johannes Lehmann of Cornell University talks Bio Char

Fri, 2008-03-07 07:23 — admin

We talk to Professor Johannes Lehmann about Bio Char

Podcast Available

Matthew Wright: Following on from our interview last week with Adriana Downie from Best Energies, we've got doctor Johannes Lehmann, whose an associate professor of soil fertility management and soil bio-chemistry at New York's Cornell University. Prior to this he co-ordinated an interdisciplinary research project on nutrient and carbon management in the central Amazon for the Federal Research Institution of Forestry at the University of Bayreuth, Germany.

His work experience includes applied and basic research in Sudan, Togo, Tanzania, Kenya, Malawi, Brazil, Columbia and Ecuador. Professor Lehmann's publications range from dry land research of nutrient recycling irrigation systems to the rehabilitation of highly weathered soils in the humid tropics. From research on phosphorous dynamics in heavily manured soils to basic principles of carbon recycling in soils.

Most recently he's been talking about terra-preta, agrichar, the ability to draw down atmospheric carbon. We'll see if we've got Dr. Lehmann there.

Good morning.

Johannes Lehmann: Good morning, and for us its good afternoon actually.

MW: Yes, good afternoon, because its late afternoon in NY and we've got you on the line from there. Thank you for joining us. Tell us a bit about yourself.

JL: Like you said, I'm a faculty member here at Cornell Uni. I'm in a dept called Crop and Soil Sciences. So, I'm a soil scientist, a soil bio-geochemist.

I'm very interested in understanding how soils work and especially how nutrient cycle, how carbon is sequestered in soil. When I was working 10 yrs ago in the central Amazon, I lived in Manaus in the central Amazon for three yrs working on degraded Amazonian soils. I couldn't help but stumble on these so-called terra-preta soils, black earth as it was in Portuguese. These black soils are scattered all over the Amazon and are very rich in humus and carbon and very fertile, and that's where all this started.

MW: So tell us a bit more about those black soils, how they came about, their longevity, and things like that.

JL: That's really quite a fascinating story. Also, the discovery of these soils, we have the earliest scientific descriptions come from about the 1860's. At that point it was absolutely unclear how these soils originated and where they came from.

There were wild theories until the 1980's that speculated whether these were soils from volcanic fallout or some old lakes that dried out; but as it turned out in the 90's only, that these soils were inhabited by indigenous populations before the arrival of the Europeans, which around 1500. The first person to travel down the central Amazon was Francisco de Orellana. He reported back to the Spanish court that there was a thriving population in the central Amazon. Productive landscapes, intensive agriculture, very large, sophisticated civilisations. Well, the Spanish came back 50 years later and the found nothing.

Then nothing was done about that. One thought that Francisco de Orellana was a liar and a cheater that just made up stories to impress the Spanish court. But now it turns out that we find these remnants of these civilisations and they provide us important clues. In turn, they taught us very important lessons that we now build a new strategy to sequester carbon and mitigate climate change on. And that's built on these soils that are clearly originating from these populations that lived there from 500 years before present to the oldest ones reported are about 8000 years old.

So in this period the populations enriched the soil with organic matter and this is still the fertility and organic matter that we see today that originated from these indigenous populations up to 7000 years ago. And its still there, in an environment where there should not be a fertile soil, where there should not be a soil with high organic matter content, and its still there after such a long period of time.

MW: So that fantastic, and the actual process to get the terra-preta is a great way to extract the energy value from biomass and even, perhaps low-caloric value biomass. Is that the case?

JL: Yes, this is a fantastic opportunity to weave this knowledge, or this insight, from old soils into modern land use and bio-energy. But let me just step one second back, its also important to realise the properties of these so-called terra-preta are not just built on ?um, that there is more humus, more organic matter in these soils. It's a very specific type of organic matter that's in these soils. It is a charcoal-like substance, a very black substance. We know of charcoal from the B-B-Q. But this is charcoal soil, and this type of organic matter is not only very stable, but it does also what other organic matter does in much more efficient way. So, its not just hanging out there a much longer period of time, but it also does all the good things that humus and organic matter does in a much better way than manure or compost could do.

And that's where these intriguing properties really, I think, are driving the current effort. And as you said, there now in the contemporary land use there are extremely exciting opportunities to produce such charcoal-like substance, we call this substance these days actually biochar because it is produced for the purpose of soil amendment, not primarily to put on your B-B-Q.

That is, of course, very exciting for the bioenergy community, because that can be produced with a certain type, with a certain method, of producing energy by using biomass. And it seems you have talked with the companies that are engaging with these technologies. The technology is called pyrolysis. Its sort of cooking biomass in a pot with the lid on, and when you do that, when your water's gone when your spaghetti's? um, then you will have a black substance and not spaghetti anymore. And that's exactly biochar. In other speak, it would be a thermal degradation of biomass, and you end up with this black substance. A bioenergy concept exists that builds on this pyrolysis, and as a by-product, that is this biochar.

Until about four years, 5 years ago, the companies and research programs that concentrated on pyrolysis were primarily concerned with producing bioenergy, until these scientific communities that looked at terra-preta and the scientific and companies that looked at pyrolysis bioenergy found out that they have a great opportunity to work together. That you can actually produce bionenergy by this process called pyrolysis and still retain a significant amount, maybe in some cases more than half, of the biomass carbon as a biochar that you can then return to soil and simulate a very important factor, why these terra-preta soils in the Amazon are so fertile for such a long period of time.

MW: At Beyond Zero Emissions, we believe in taking our atmospheric carbons as close to near zero emissions as possible, and then trying to balance that. Of course, agrichar can be one way of doing that. Then we're talking about actually pulling down the carbon debt. That's the carbon that the West has emitted in its industrialisation, which is about 200 billion tonnes. Do you see enough land that's appropriate to sort of achieve that sort of pull-down in a short period, in 10, 20, 30 years sort of thing?

JL: Absolutely, and I can tell you why I think that, but what I explain now is of course a theoretical potential that's not fettered??? 11:19 against economic realities of competing strategies and political influences. Why I think it is possible, because you can do calculations and look at waste biomass in agriculture or forest thinnings, agricultural by-products, crop residues, etc. These taken together would be more than enough to put a significant dent into the rising co2 curve. Conversely, there are more than enough soils that would need boosted soil fertility and could very well need this biochar. It is entirely conceivable that this can play a major role.

Another factor is that this is a technology that already exists. It is not something where we speculate that we have the development of 5 or 10 years until we get to a stage where it's technologically feasible. This is technologically feasible right now. And it is not a very complicated technology. It is a very ancient technology in its basic function and charcoal making is one of the most ancient technologies that humanity invented. It's a very, very old technology. However, producing energy from that technology requires quite a bit more technology, but the mere process of converting biomass into biochar is a very ancient and basic technology and can be done in massive proportions within a very short period of time. I think it's a very important opportunity that we should have a very close look at.

Of course, there's a multitude of competing and old intelligent solutions, to our energy, as well as climate, problem. And I think that there are other bioenergy options that deserve a very close look and have definitely a place in a portfolio of options. But I can't see that there's another opportunity such as pyrolysis with a biochar return to soil that offers clear carbon-negative bioenergy where for every unit of energy that you produce you're actually net-sequestering carbon in the terrestrial ecosystem, or anywhere on Earth.

MW: Just to let listeners know, we're talking to Johannes Lehmann whose an expert in soil fertility and bio-geochemistry. You're with Radio 3CR and its 8:45AM.

Dr. Lehmann, we've talked about the pyrolysis machine and how we can actually cook up the biomass, which can be a biomass residual from cropping, or something like that, and then getting the synthetic gas which is carbon monoxide and hydrogen and turning that into a viable fuel, and then sequestering that residual char and with each new crop we can perhaps pull down 50% of the carbon, (by mass of that actual crop)?you're giving us a solution to those two things and also you talked about the fact that we could probably get marginal lands and restore those. So this is going a long way. We're taking marginal farm land and restoring that, we're drawing down atmospheric carbon to start getting rid of that carbon debt, and we're creating a fuel source. Can it do all these things?

JL: It can where its given the opportunity to. You have to realise that there are of course a lot of soils that are already good. A farmer in the American Midwest that already harvests 9 tonne of corn grain, or 8 tonne of corn grain, that farmer will certainly not double the yields of their crops. But they might be able to reduce the fertiliser amounts because biochar in soil is able to retain more of the fertiliser that is added to soil and thereby possibly reducing the costs of fertiliser additions and other unwanted offside effects such as groundwater pollution or eutrophication of surface waters. That is always a question of the site that you are working at and the objectives that you follow and the priorities.

I have talked with farmers who are right now producing biochar on their farms with large scale pyrolysis machines that are absolutely not interested in producing bioenergy. They're completely content in producing biochar from sustainable biomass production and putting that biochar in soils without even thinking of bioenergy at this point. There might be others who are interested in remediating soils in remote areas in mine??? soils where it also would be difficult to transport the energy anywhere else; it would cost more energy than the energy is worth begin with.

If the objective is to remediate soils and its worth your while doing that without harvesting the energy that is gained from this process, then that's fine too. You might in some cases opt for um, if energy prices are high, and at the moment you have a problem selling your biochar, you might produce only energy. The versatility is really great and you can decide which markets you want to tap.

MW: Given the finite resources, and the finite land mass to feed an ever growing population around the world, it's generally the case that you're going to get the heat by-product and you're going to have the char at the end, so I guess it would be best that all things are harvested from the process. Would you agree with that?

JH: Most definitely. Absolutely, but there's a limitation. If you have a remote area, if you're producing energy in a remote area, you have 2 choices. Either you're transporting the biomass which costs a lot of energy or you're producing the energy where the biomass is produced and then you have to transport the energy to some end user. The proximity of biomass production, energy production, and energy consumption is key for any bioenergy concept. There are clear thresholds from which distances this system would not work any more.

But that means it has great strength in distributed energy production, for farms, for small farms, I'm thinking for instance Africa where there you have a lot of energy use from biomass individually from households, and in small villages. If these households and these villages could be equipped with pyrolysis bioenergy rather than complete burning of their biomass, they could get the same amount of energy out of the biomass that their using, cook the same amount of food per day that they were cooking with their identical amount of biomass and still retain about half of their carbon to be returned to their ever degrading soils. This could mean a tremendous change that would be largely driven by the need to restore soil fertility but by the same token possibly make a significant contribution to mitigating climate change.

MW: And of course, that what we're here for at Beyond Zero. Dr. Lehmann, in terms of, before we touched on those high yield farms where there was possibly decreased requirement for fertilisers, and a lot of fertilisers are actually sourced from petroleum products which of course have embodied carbon in the process of exploration, extraction, distribution, cracking?do you see that that is the case, that we could mitigate the need for much of those petroleum-based fertilisers?

JL: Our hope is to demonstrate clearly that we can significantly reduce the need. Any plant needs nitrogen. For instance, nitrogen is the single most energy intensive, therefore carbon intensive fertiliser nutrient. Typically around 50% of the energy that goes into any given agricultural product that you buy off the shelf comes still from that energy used for the nitrogen fertiliser during production on land. So achieving a significant reduction in the use of that nitrogen fertiliser could have a significant effect on the energy consumption and carbon balance of an agricultural product. I would be perfectly content if we can reduce the nitrogen need of the cereal crop by 20 or 30%. That would be a huge achievement.

Of course we will never be able to completely reduce it unless we are working with legumes, and biological nitrogen fixation, which is entirely feasible as well. But in intensive role production in much of the world, unfortunately, most farmers still have to work, presumably, with mineral fertilisers. But I believe we will be able to demonstrate that these can be reduced.

Then there's always still a significant jump to make from demonstrating on a research farm, or even on farm research, that you can decrease and still get the same amount of yield and the adoption by farmers. So that will be a much more difficult sell to get farmers to decrease their fertiliser amounts from a yield safety perspective. But eventually, and with rising energy, and therefore rising fertiliser prices, I believe that there is enough economic reason and economic incentive to look for any opportunities to be able to reduce fertiliser additions.

MW: So the reduced requirements for nitrates and nitrogen, could that actually help with the introduction of bio-fertilisers; the fact that you don't need to go as far if you combine the two opportunities?

JL: That could very well be. That is really a far-reaching question, and whether we can actually achieve to combine the two and package an attractive management scenario. That would be the ultimate goal, and I can see that there is a lot of merit in researching that further.

MW: Also, now I understand that there are a lot of trials under way. How are they progressing? Can you give us an idea of what the early results are, and if there was a lot of help and assistance, how quickly could we get this stuff commercial?

JL: That is really the single greatest challenge; to scale it from laboratory investigations to significant farm-scale trials. And why this is a challenge? Because for doing that you need a significant amount of that biochar for doing field scale studies. And the catch 22 at this moment is that there are not enough companies around that produce a biochar with facilities of the scale that would be conceivably be installed in the future, in a biochar economy. Therefore the research is greatly hindered by the availability of commercial plants that work on this basis. And since these are quite significant power plants, this is also an undertaking that can't be just done by individual researchers in their programs. These are university wide, or program wide initiatives of a 'Department of Energy' scale that is beyond research scale. That is a huge drawback of the current situation. But the handful or so of trials that are under way, and a significant amount of these trials are actually situated in Australia, so far they all show very promising results but also some results where we clearly see that there is absolutely the need for optimisation to biochar products. Not all biochar products are efficient to the same extent, and there might be even be some biochar products that are detrimental to plant growth, similar to any fertiliser. You can apply too much of a fertiliser and kill your crop. You need to have the right dosage and the right composition of fertiliser. And the same applies to compost or manures, and of course the same applies to biochars.

The density of data, and the intensity of research, needs to be accelerated to a significant extent to fine tune and identify those biochar types that are the most effective for increasing crop yields. But that can be done by extension agencies, and on extension farms, with on-farm trials very quickly, within a couple of years. Again, the technology is there, we've just got to implement it.

MW: Great. Thank you, Dr. Lehmann. We've been speaking to Johannes Lehmann from Cornell University, who's an expert in soil fertility management and soil bio-geochemistry. It was a most interesting and intriguing discussion, and we'd love to have you back on the show in a few months if you'd be happy to do that.

JL: It was a pleasure.

MW: Fantastic. And I think our listeners will agree that we're all the wiser now. Just in one or two words, do you think we can start some initial, small-scale commercial stuff right away, or are we five years away.

JL: Absolutely, we should be starting this right away, and hopefully that will enable the farmers, that are ultimately the best researchers, to kick into gear and try this out and find out what works best for their soils and for their crops.

MW: Great. Thank you Dr. Lehmann. You're with the Beyond Zero show and just to wrap up we'll see you all tomorrow at the Sustainability Convergence which is at Northcote High School?