Showing posts with label terra preta. Show all posts
Showing posts with label terra preta. Show all posts

Thursday, January 21, 2010

El Dorado Located







As I have posted on extensively, the creation of terra preta soils permitted dense urbanized Stone Age populations.  Present day clearing activity is now exposing their presence for the archeological record.

 

It is noteworthy that these cities show dates only as early as 200 AD.  This is likely a result of limited sampling.  The tool set necessary was already a couple of thousand years old.  This is common though for such dating because most samples come from areas representing the maximization of the culture and likely miss the long early development.

 

The late dates support the idea that the whole society was extent when the new world was discovered.  Once again Europeans did not so much as miss these antique civilizations so much as their pathogens got there first and threw these societies down.  The nastiest pathogen was the slave trade of course.

 

With out question, these were states and they certainly fit the story of El Dorado.  They most likely decorated buildings with gold and this enhanced the story.  We are not seeing stone structures but we did not see them in Mesopotamia either.  We have mounds and these were certain to hold wood frame structures of the leaders.

 

Terra preta made possible an Amazonian population in the tens of millions.  The culture itself most likely prevented it from happening except for locales like this.



 

Amazon explorers uncover signs of a real El Dorado

 

Satellite technology detects giant mounds over 155 miles, pointing to sophisticated pre-Columbian culture




An aerial picture of traces of earthworks built by a lost Amazonian civilisation dating to 200AD. Photograph: National Geographic
It is the legend that drew legions of explorers and adventurers to their deaths: an ancient empire of citadels and treasure hidden deep in theAmazon jungle.
Spanish conquistadores ventured into the rainforest seeking fortune, followed over the centuries by others convinced they would find a lost civilisation to rival the Aztecs and Incas.
Some seekers called it El Dorado, others the City of Z. But the jungle swallowed them and nothing was found, prompting the rest of the world to call it a myth. The Amazon was too inhospitable, said 20th century scholars, to permit large human settlements.
Now, however, the doomed dreamers have been proved right: there was a great civilisation. New satellite imagery and fly-overs have revealed more than 200 huge geometric earthworks carved in the upper Amazon basin near Brazil's border with Bolivia.

Spanning 155 miles, the circles, squares and other geometric shapes form a network of avenues, ditches and enclosures built long before Christopher Columbus set foot in the new world. Some date to as early as 200 AD, others to 1283.
Scientists who have mapped the earthworks believe there may be another 2,000 structures beneath the jungle canopy, vestiges of vanished societies.
The structures, many of which have been revealed by the clearance of forest for agriculture, point to a "sophisticated pre-Columbian monument-building society", says the journal Antiquity, which has published the research.

The article adds: "This hitherto unknown people constructed earthworks of precise geometric plan connected by straight orthogonal roads. The 'geoglyph culture' stretches over a region more than 250km across, and exploits both the floodplains and the uplands … we have so far seen no more than a tenth of it."
The structures were created by a network of trenches about 36ft (nearly 11 metres) wide and several feet deep, lined by banks up to 3ft high. Some were ringed by low mounds containing ceramics, charcoal and stone tools. It is thought they were used for fortifications, homes and ceremonies, and could have maintained a population of 60,000 – more people than in many medieval European cities.
The discoveries have demolished ideas that soils in the upper Amazon were too poor to support extensive agriculture, says Denise Schaan, a co-author of the study and anthropologist at the Federal University of Pará, in Belém, Brazil. She told National Geographic: "We found this picture is wrong. And there is a lot more to discover in these places, it's never-ending. Every week we find new structures."
Many of the mounds were symmetrical and slanted to the north, prompting theories that they had astronomical significance.
Researchers were especially surprised that earthworks in floodplains and uplands were of a similar style, suggesting they were all built by the same culture.
"In Amazonian archaeology you always have this idea that you find different peoples in different ecosystems," said Schaan. "So it was odd to have a culture that would take advantage of different ecosystems and expand over such a large region." The first geometric shapes were spotted in 1999 but it is only now, as satellite imagery and felling reveal sites, that the scale of the settlements is becoming clear. Some anthropologists say the feat, requiring sophisticated engineering, canals and roads, rivals Egypt's pyramids.

The findings follow separate discoveries further south, in the Xingu region, of interconnected villages known as "garden cities". Dating between 800 and 1600, they included houses, moats and palisades.
"These revelations are exploding our perceptions of what the Americas really looked liked before the arrival of Christopher Columbus," said David Grann, author of The Lost City of Z, a book about an attempt in the 1920s to find signs of Amazonian civilizations. "The discoveries are challenging long-held assumptions about the Amazon as a Hobbesian place where only small primitive tribes could ever have existed, and about the limits the environment placed on the rise of early civilisations."
They are also vindicating, said Grann, Percy Fawcett, the explorer who partly inspired Conan Doyle's book The Lost World. Fawcett led an expedition to find the City of Z but the party vanished, bequeathing a mystery.

Many scientists saw the jungle as too harsh to sustain anything but small nomadic tribes. Now it seems the conquistadores who spoke of "cities that glistened in white" were telling the truth. They, however, probably also introduced the diseases that wiped out the native people, leaving the jungle to claim – and hide – all trace of their civilisation.
• This article was amended on Wednesday 6 January 2010. Percy Fawcett's experiences in the Amazon were said to have partly inspired Arthur Conan Doyle's book The Lost World, but Fawcett's disappearance did not, contrary to a suggestion in the original article - he vanished after the book was published. This has been corrected.




Monday, June 8, 2009

Dr Francis Ng on Horticultural Carbon

This is a surprising article that fills in some of the blanks in our knowledge of terra preta. It makes it clear that minimal practices establish the viability of carbon based gardening. That it devolved into something much bigger in the Amazon was surely initiated by an awareness of their backyard gardens and the obvious importance of carbon.

More delightful is the description of a carbon only media for growing rice in a pot. That should eliminate any residual doubts anywhere. The association with tropical clays is also very encouraging. A lot of questions just got well answered in a positive.

Field carbon application needs to go on for years to create ideal conditions, as a single year is able to add a percentage point as per my corn culture approach. My suggestion to focus on seed hill methodology appears sound because of this. Seed hills and low tillage will provide a large amount of usable carbon in just a few years.

It is noteworthy that this work has been done with wood charcoal, likely in the form of roasted sawdust. This option is unavailable in the normal course of events and the argument here suggests a mixed process in back yard garden plots. Certainly. The back yard garden plot was the back bone of Amazonian terra preta. This conforms the process.

It is noteworthy though that the practice was extended into large fields in the Amazon at a far less intense level and likely associated with the use of corn culture which gave the bio mass volume.
More startling here is that it is feasible to use a straight carbon as a growing media by itself. Lousy for holding water, but that is no drawback in a very wet environment were rot becomes a major control problem.

Monday, May 25, 2009

Horticultural carbon, terra preta and high performance horticulture in the humid tropics
http://tropicalhorticulture.blogspot.com/2009/05/horticultural-carbon-terra-preta-and.html


I have received many enquiries about the horticultural carbon that I use to create the rooftop 'Secret Garden of 1 Utama'. To make it easier to deal with queries, I have prepared the following account, to be published in a journal. Please bear with the stiff format and language, which is a journal requirement.
Introduction

Soils in the humid tropics tend to be highly clayey. Clay particles stick together to impede passage of water and air, and this is detrimental to root growth. Without sustained effort keep clay soils open and porous, tropical soils rapidly become unproductive. Growers resort to many different methods of farming on clayey soils. For example, vegetable growers till the soil after each harvest and pile up the loosened soil to form raised beds. During each watering session, water soaks in and drains out easily, thereby simultaneously renewing the supply of water and air in the soil. A good soil is analogous to lung tissue in that both have large internal surfaces to hold moisture and air. Unfortunately the effect of tilling lasts only for a few months.

Clay soil may be burnt over a hot fire, in the process of which it becomes crumbly (Holttum 1953). Burnt soil maintains its crumbly structure for up to one year, and such soil is often used for container gardening.

However, the most favoured soil for horticulture is garden black soil, which goes by the Malay name of tanah hitam (black soil). Black soil originated in household backyards where domestic waste was dumped and periodically burnt. The black colour was due to the accumulation of charcoal and soot in the soil over time.

Tanah hitam in Malaysia seems to be very similar the soil in the Amazon known in Portuguese as terra preta (black earth). Terra preta soils are very fertile and contain a high content of carbon (about 10%). They occur on sites that appear to have been permanent native settlements for centuries before their populations were wiped out by diseases brought in by the Europeans. It would have taken centuries of firewood burning on the same sites to have produced black soil in the vast quantities, to 2 m deep in some sites. The discovery of terra preta sites has created a lot of discussion in the Internet about its origin.The development of horticultural carbon

Open burning has been prohibited for many years in Malaysia, hence black soil is no longer available. Needing a large volume of good soil to establish a rain forest in the ‘1 Utama’ shopping mall in Kuala Lumpur, I decided to make such a soil by mixing charcoal particles with soil. We made this soil by mixing normal clayey soil (mostly subsoil) with charcoal and coconut fibre in equal proportions by volume. The charcoal was conventional charcoal produced by the kilning of mangrove wood. This came in large hard pieces that had to be broken up mechanically. The resulting particles were irregular in size and difficult to mix with the clay and fibre. I then found a much better source of charcoal in the factory of a charcoal briquette manufacturer. Charcoal briquettes are made by compressing sawdust into standard-size briquettes for kilning. The briquettes, meant for the barbecue market, can be easily broken into particles, sieved to remove dust and graded into the desired sizes. We refer to the product as horticultural carbon (Ng, 2006). We use two sizes: 1 – 4 mm particles for potting mixtures and 5 – 12 mm for garden beds.

We have found that a mixture of equal parts horticultural carbon and clay soil is good for general purpose horticulture. A mixture of three parts carbon to one part soil is better for cacti and succulents that need exceptionally well-drained soil.

Horticultural carbon is half the weight of soil, so the mixtures we make are lighter and more porous than ordinary garden soil. The reduction in weight was an important factor in my next project, a garden on the roof of the same shopping mall, seven floors above the ground. This garden, known as the Secret Garden of 1 Utama is now open to the public at weekends.

The porosity of soil mixed with horticultural carbon greatly reduces the labour of weeding because the weeds can be pulled out easily. However horticultural carbon only holds half the amount of water that an equivalent mass of clay soil will hold. Its lower water-holding capacity, together with its porosity, means that horticultural carbon dries out much faster than clay soils. The drying of the soil medium can be very damaging to the roots of plants, hence we find it necessary to keep our medium kept moist all the time. This can be arranged in various ways, for example, by watering twice a day. In pots, we would recommend placing the pots on shallow trays to hold water.

Horticultural carbon does not contain nutrients, hence fertilizers have to be applied regularly. Initially the carbon and clay particles remain separate though mixed. Gradually the carbon wears down and becomes integrated with the clay, with consequent settling of the soil mixture. The soil level drops and is topped up with pure carbon.

The performance of plants on horticultural carbon

Our most extreme experiment was to grow rice on 100% horticultural carbon in plastic basins. The basins, about 20 cm deep, were three-quarters filled with carbon particles and topped up with water. Rice seeds were sown direct on the surface. Our Indonesian workers, rice-growers in their former lives, all had a good laugh because “everybody knows that rice only grows on tanah liat (sticky clay soil)”. Well, our rice grew and produced a heavy crop of grains. We have now grown three successive crops. The roots form very dense mats. After each crop, the roots have to be dried out before the carbon particles can be shaken out and recovered..

For cacti and succulents, we use a mix of 75% carbon to 25% burnt soil in elevated beds. Some species thrive, but some still find it too wet, and rot when it rains daily. Nevertheless ours is the only decent-looking cactus bed exposed to tropical rain in Kuala Lumpur.Begonias, calatheas, and aglaonemas grow well in 50:50 mixes on raised beds provided 50 - 75% of the sunlight is cut off using shade-nets.

Of temperate plants and montane plants, we have managed to grow apple, peach, plum, Magnolia grandiflora, Magnolia liliiflora, arabica coffee, azalea, camellia, day lilies and Platanus. It has been hypothesized that in the tropics, the high night-time temperatures raise the night-time respiration rate to a level that temperate plants cannot adapt to. We think a high carbon mix allows air (oxygen) to get to the roots more easily, making it easier for temperate plants to adapt. However the flowering patterns of temperate plants are disrupted by the lack of seasons. Some species do not flower at all (e.g. day lilies), some flower infrequently and sparingly (e.g. apple and plum), and some flower all through the year (e.g. Magnolia liliiflora and arabica coffee).

Where to see horticultural carbon in use

In Malaysia, the Secret Garden of 1 Utama in Petaling Jaya, occupying 0.25 ha of flat roof top 7 floors above the ground, is the largest display open to public view. Here are grown over 500 species of plants, including palms, orchids, temperate plants, flowers, spices, rice, cacti, climbers and grasses. Also in 1 Utama but on the lower ground floor, is a rainforest with some 50 species of timber trees growing on a horticultural carbon mixture. In Sarawak, the Laila Taib Ethno Garden of the Sarawak Biodiversity Centre at Semengok, Kuching, displays a good range of native herbs grown on horticultural carbon, most of them larger and healthier than in their original rain forest habitats.

Horticultural carbon in carbon sequestration

Since the Industrial Revolution, the amount of carbon dioxide in the atmosphere has increased significantly, to bring about global warming. The increase in carbon dioxide in the atmosphere is due partly to the extraction and burning of coal and petroleum and partly to the clearing of forests, which reduces the amount of organic carbon stored in forests. Proposed measures to control global warming include reduction in consumption of coal and petroleum and the planting of trees and forest to convert atmospheric carbon dioxide into organic carbon. However, reduction in consumption has proven to be difficult, and trees and forests fix carbon efficiently only when they are in active growth, i.e. during their juvenile phase. When trees die, organic carbon is converted back to carbon dioxide through the normal processes of decay.

The conversion of wood to charcoal fixes carbon more permanently and the use of such carbon as a horticultural medium kills two birds with one stone. Horticultural carbon acts as a carbon store but instead of being just a passive store, its use as a high performance horticultural medium helps to solve the other global problem, of increasing food production in the world. On our roof top garden the average use of horticultural carbon is 1 tonne (equivalent to a volume of 2 m3 ) to cover 6m2 of floor area. Our manufacturer of horticultural carbon is
yoltan@tm.net.my

References

Holttum, R.E. 1053. Gardening in the Lowlands of Malaya. Staits Times Press, Singapore.

Ng, F.S.P. 2006. Tropical Horticulture and Gardening. Clearwater Publications, Kuala Lumpur.

Tuesday, June 2, 2009

Biochar Pellets

This posting on biochar is an easy read and more interestingly raises the point that the carbon product is possibly a good product to pelletize. In fact, I would both pelletize the product and then dip it in paraffin to make it easy to handle. It may even be possible to add nutrients at that point depending on the solubility of such in paraffin.

These are commercial considerations that become important if one has a huge feedstock at hand. The paraffin would slow down the degradation of the pellet but that may also be an advantage with many crops such as trees and row crops. If nutrient loaded, an initial breakdown cycle lasting out the season is surely useful and helps set thing up for the next crop.

Again this commentator has fallen for the wood based biochar scenario which is difficult to avoid. In practice, wood needs to be avoided because of unwelcome retention of large scale integrity and real crushing costs.
The source is an unidentified poster on this forum.

http://forums.canadiancontent.net/science-environment/84309-bio-char.html


I wrote this for a bio-pellet maker's forum and thought I would pass it on for you to read.

Char is very easy to make in the bon-fire season. An air tight metal container, with a single airhole, is all you need. But your wood inside seal the can, not the airhole, and place on the bon fire. You will see gases come from the hole as the wood inside chars. When the gases stop coming from the hole plug the hole with a stick and remove the can from the fire to cool overnight with the plugging stick in place. The next day you remove the lid and you will have nice chemical free charcoal for the BBQ and compost pile.


Hello, I am new to the forum and to pellet making altogether really. I am an open researcher of the net at the present time have become interested in many topics I come across. The downfall of the net, for some, is that there so much information, it can boggle the mind.

I ran across the videos put out by the web site on YouTube and decided to pose a question to the site administrator. They still have not gotten back to me, but I think from the posts on the forum you are a pretty busy group - he is likely looking into it.

The newest thing on the 'Save the World' front is Bio-char. I asked if the pellet machine would be able to convert bio-char into a pellet form. I do know that the bio-char can be hand pressed, or screw extruded into briquettes. This is done in many countries around the world. What I think would work the best is the small pellets that your group are making.

I will give a little bit of back ground for my idea. Researchers who have explored the rain forests of the Amazon have come across a soil type which is man-made. They call it 'Terra-Preta' or 'Dark Earth'. I have found out that the soil of the rain forest is not particularly suited to growing vegetation (this surprised me) and the ancient civilizations in the area would treat the soils. These plots of land they are finding today are estimated to be 100's of years old (in terms of last use) and are amazingly fertile as compared to other soils in the immediate area. They only run 4-5 feet in depth and cover the known growing plot area of the period. Today’s natives actually hunt out these plots and sell the fertile soil as an income.
The keys to this fertile soil is a high carbon content and pottery chards. Both materials are very porous in nature. What happens is the nutrients that come to the treated soil gets trapped in the pores of the material and are held there, rather than being washed straight through the soil. These nutrients are then extracted from the material be the root systems of the plants as they grow. As the spaces in the material open up again they are refilled with newly arrived nutrients. This material has proven that it can remain in the soil for 100's of years - as is found in the 'Terra-Preta' plots.

By the way these plots are not isolated to the Amazon they are found around the World in different areas. The thing is that the way they are made - the technique was lost. These plots around the World are being used up and the farmers are running out of nutrient rich natural (organic) soil. Some feel that the burning of the fields in the way to go as it has been done that way for ages. Well, the soil is dying and it working. The soils are being depleted. Plant matter which is made of carbon, takes its building blocks from the soil and therefore the soil is lacking carbon after centuries of use. But, because we had one lazy, or work saving generation, who knows how long ago, we have lost the technique of how to care for the soils.

Tests run in Africa are showing an amazing 500+% increase in crop yields in the first year. They are still using un-organic fertilizers as that is what they thought they needed, but that can change now. Their soil is so bad in some areas that nothing would grow. If any farmer could get a 20% increase in annual yields they would be happy.

The reason that the use of chemicals came into large use was because of the depleted soils. If the chemicals did not wash away (trapped in the carbon for future use) there would be less need in the future. Ideally there would be none needed in the future.

So what are we doing? At present we grow plant material, burn it, and release the carbon into the atmosphere. I don't go for the global warming thing, but do feel it is not a good thing happening. The dirt on my car every day tells me that things are changing for the worse - I didn't see that as a child.

What we can do is grow the plant material, burn a portion of it to covert another portion of the material back into carbon, and put that carbon back into the soil. This cuts emissions to the air (from that aspect of society) to 50% of what it was. Pellets can play a big part in this.

My idea was to convert plant matter to char and the char to pellets. The pellets would be good as they are finding in test fields that the microbes in the soils like to grow in the larger pieces. 'It makes the soil happy' - they have a community of their own. You do not want too large of chunks as that makes the soil difficult to work with. Too small of piece (on surface soil) will be blown away on windy days. The windblown soil may not seem like a big thing, but the carbon has the nutrients now remember. Keep all you can on the fields instead of the forest. If you wish to recarbonize the forest soil, spread it through the forest in your spare time.

It should be said here that the carbon upon introduction to the soil will deplete the soil of nutrients at first. This is the carbon 'charging' itself. The pores of the carbon are filling and will have the nutrients there; it just looks like the nutrients are gone. This is why it is a good idea to pre-charge the carbon before introduction to the soil. Mix it with compost or manure for a couple of weeks and let the pores fill. The nutrients will then be added to the soil with the carbon. This where the pottery chars they find in 'Terra-Preta' come from. They are the holding vessels from the indoor urinals and toilets - charged and stinky they were broken in the fields.

This may not work as far as making pellets from bio-char goes. What about bio-char from pellets. This would be easy to test for you people. You have the machines and the wits to do it. The market is there if you want to sell the end material. Every back-yard composter, in every city will want this stuff.

I hope I wasn't too long winded on this. It is an important topic, especially if you are a rural resident. City dwellers with a green thumb can help, but the rural residents hold a majority of the bio-matter.

For more information Google 'bio-char' also 'making charcoal from wood' you can get into the worm castings and all that, but once the nutrients are in your soil the rest of the good things will come and live there without help.

Wednesday, April 8, 2009

Stone Age Forestry

I am reading a book published in 2003 by Nigel Randell titled ‘The White Headhunter” about a British sailor marooned on the island of Malaita in the Solomons for eight years ending in the early 1870’s. The society he entered and impacted was Stone Age, well organized and remarkably similar to the society of pre Columbian Brazil including the ritual sacrifice of enslaved captives. This book informs us of the lifeways of these societies and their stresses rather well. It is not the eyes of a trained anthropologist but of a captive who needed to make himself valuable to the tribe and having little hope of escape.

Most valuable, we get a report on the felling of a tree, using Stone Age technique. This had been discussed by those debating the origins of terra preta soils in the Amazon. Manu had expected that the carbon had come from the reduction of the forest itself. I had argued that Stone Age technology lacked the necessary productivity, but had no referents to support that position, unless common sense can be scientifically quoted. It is noteworthy, however, that once the steel ax became available that bush natives switched immediately to slash and burn agriculture.

I quote as follows;

“Bush life was shaped around the wrestling of subsistence from the land. Families depended upon a continuing harvest of starchy food with the staple diet consisting of taro, with yams providing a seasonal change. Gardening was exhausting labour as the land had to be cleared. The bases of the huge hardwood trees were burned and stone adzes used to chip away at the charred wood. This process of burning and chipping was slow work; each tree would take four days to fell. The cleared land could only be used for one planting, then left to lie fallow to renew the feeble fertility of the soil. There was little in the forest to supplement their diet except tree grubs, frogs, and lizards. What bush people always craved was fish.”

The advent of terra preta soil culture in exactly this type of tropical subsistence environment was a productivity revolution. The use of biomass, and more specifically the use of maize stover as a biochar feedstock, provide sufficient product to immediately plant a successor crop using the three sisters protocol or even just more corn. Two days work would surely gather the stover and generate the necessary earthen kiln in the garden patch. Obviously such a bush tribe would base themselves close to good fishing and a lot of fish waste would also accumulate.

This quote clearly establishes the forest management limits of a Stone Age society and shows us that the use of wood for charcoaling was massively labour intensive and not a practical option.

It is also noteworthy that the best Stone Age adze technology of the North West Indians allowed fairly modest totem pole work. It was only the advent of the steel ax that allowed the art to blossom into today’s forms and size.

Monday, March 2, 2009

Batibe in Cameroon

I have here a report from West Africa in which indigenous peoples produce biochar from elephant grass which is an ample source of biomass. This is another example of indigenous ingenuity that has produced productive soils comparable to the terra preta soils of the Amazon. It is easy to see corn stover been fitted into this method for the same reason.

I have recently been able to discount the use of pottery as an important active factor in the Amazon. It simply does not show up in terra mulato. That made the simple earthen kiln as the best possible explanation. Here in the Cameroon we have a field length earthen kiln produced and then lit. It is a good bet that the earth collapses behind the burn front helping smother the produced char.

Corn is obviously much more bulky but the same method could well apply. I still think that building a vertical stack with the root balls forming the outer shell is likely to be much more effective for corn.

The important point though is that biochar is a living indigenous practice in this part of West Africa.

http://e-terrapreta.blogspot.com/2009/02/soils-near-batibo-cameroon.html

The Batibe technique was described to us as to work as follows: before the planting season, farmers collect big piles of elephant grass or any other type of savannah grass, which they spread out over their fields to dry it. After the grass has dried, they pile it so as to make long strips, on which they will grow their crops. Then they cover the big rows of grass with a layer of mud, which they leave to dry again. After the mud has dried and hardened, they open one part of the strip and set fire to the grass contained in this "container". The fire travels slowly through this "kiln", providing a low oxygen environment, and chars all the biomass. After this operation, they crush the mud layer, and the char beneath it. They repeat the effort several times to create layers of char and crushed mud. This then becomes their soil bed, on which they start planting crops when they rains arrive. The rains turn this soil layer into an apparently fertile soil. To our own amazement, the farmers of our workshop in Kendem immediately understood the biochar concept, because of their knowledge of this Batibe technique.

Laurens Rademakers

Tuesday, February 24, 2009

Legacy Landscapes of Amazonia

This is an article that surveys current knowledge that has been accumulating over the past decades and accelerating recently with the growing comprehension that the Indios conducted extensive settled field agriculture throughout the Amazon Basin in pre contact times. I find it very helpful, even though it is still a long way from the final answer of pre contact populations. Most encouraging to myself is that the consistent application of terra preta and terra mulato soils allows us to ultimately map truly settled lands like nowhere else in the world. We will ultimately get a measure of optimum population at the time of conquest.

I have also answered another question. While terra mulatto is much more prevalent than terra preta as it represents fields away from the actual village gardens, it holds no pottery. This is rather good news since it implies that pottery was not central to the manufacture of terra preta or terra mulato soils.

As I have extensively posted, the special characteristics of corn permit the easy construction of earthen kilns, not dissimilar to traditional charcoal kilns which are sealed up with mud. I had conjectured that pottery had been used to bring a hot coal charge to the kiln or even perhaps that it had been slathered over the outer mud surface to give better closure. I also felt that this might be a lot of unnecessary extra work but was confronted with the huge amount of pottery associated with the village gardens.

This clarifies the situation. In the open fields, the earthen kilns were ample and sufficient. Recall that a field of maize will produce a ton of biochar per acre which is sufficient to properly set up seed hills for the next season’s crop. An earthen kiln takes just a little extra effort to construct properly on top of the effort needed to pull the dried stalks at the end of harvest.

The pottery associated with the village gardens are no more than the natural build up of broken material accumulated over two thousands of years caused by using very inferior pottery making methods. Some could easily have been made by lining baskets and were meant to be entirely temporary.

It such basket pots were then used as cooking pots heated by cooking stones, the attrition would have been atrocious. Thus a massive amount of pottery in the kitchen garden is very believable.

The other aspect of Amazon antique civilization is that is was as well developed as the rest of Mesoamerica without the luxury of stone pyramids. There were a number of polities quite separate from each other and probably suppressing intervening development. To put this into perspective, the Amazon Basin is much larger than all of Europe and we have polities connected at best by rivers that held populations in the tens of thousands at the least yet sufficiently distant from each other as to discourage conflict. There were many of them and with satellite mapping we are beginning to grasp their scale.

It is this separation that likely kept the populations lower than is possible from the carrying capacity of the land, but the carrying capacity of the land used was extraordinary to begin with. Today we are barely exploiting the full potential of these lands and it is reasonable to say that if modern Brazil’s current occupied lands were reduced to the same level of culture that ninety percent of the lands would be withdrawn from cultivation. Yet however you wish to play with the assumptions, the occupied lands at the time of contact held millions and possibly tens of millions and was certainly up to handling a hundred million or more unlikely as that may seem.

We are now beginning to grasp just how much has been lost at the time of the contact. A real percentage of the Mesoamerican population managed to survive the impact and through the process of hybridization began a long recovery under the umbrella of a European organized polity. The Indians of the Amazon were not so lucky. Disease decimated them again and again allowing the remnants to be over run by the barbarians of the forest who still dominate many areas. This is a natural process and inevitable considering that ritual cannibalism was practiced throughout these polities as a derivative of such ongoing conflict.

I also have good reason to think that similar polities arose in the Mississippi Valley and have also gone unremarked to this day. The impulse was there and corn culture could support it. We also have the evidence of the mound builders to support the likelihood.

http://westinstenv.org/histwl/2009/01/11/the-legacy-of-cultural-landscapes-in-the-brazilian-amazon-implications-for-biodiversity/
The legacy of cultural landscapes in the Brazilian Amazon: implications for biodiversity

Michael J. Heckenberger, J. Christian Russell, Joshua R. Toney, and Morgan J. Schmidt. 2007. The legacy of cultural landscapes in the Brazilian Amazon: implications for biodiversity. Phil. Trans. R. Soc. B (2007) 362, 197–208

Full text [
here]

Selected excerpts:
Abstract

For centuries Amazonia has held the Western scientific and popular imagination as a primordial forest, only minimally impacted by small, simple and dispersed groups that inhabit the region. Studies in historical ecology refute this view. Rather than pristine tropical forest, some areas are better viewed as constructed or ‘domesticated’ landscapes, dramatically altered by indigenous groups in the past. This paper reviews recent archaeological research in several areas along the Amazon River with evidence of large pre-European (ca 400–500 calendar years before the present) occupations and large-scale transformations of forest and wetland environments. Research from the southern margins of closed tropical forest, in the headwaters of the Xingu River, are highlighted as an example of constructed nature in the Amazon. In all cases, human influences dramatically altered the distribution, frequency and configurations of biological communities and ecological settings. Findings of historical change and cultural variability, including diverse small to medium-sized complex societies, have clear implications for questions of conservation and sustainability and, specifically, what constitutes ‘hotspots’ of bio-historical diversity in the Amazon region.

INTRODUCTION
The preservation of tropical forests in the Amazon is central to current debates about environmental and climate change across the globe. Greater Amazonia, which refers to the largely forested Orinoco and Amazon river basins, preserves nearly one half of the world’s remaining tropical forests. It contains nearly a quarter of the world’s fresh water and produces roughly one-third of the world’s oxygen, over an area larger than Europe (nearly one-third of South America). According to The Nature Conservancy (TNC website: www.nature.org; consulted 2December 2006), Amazonia is also home to over one-third of the Earth’s known species, and as such is one of the most critical reservoirs of biodiversity on the planet. Not surprisingly, concerns over biological conservation and the future of the region as a critical ‘tipping point’ in the Earth’s climate and ecology are widespread.

The discovery of remarkable variability within Amazonia over the past few decades has overturned popular characterizations of the region as a fairly uniform, impenetrable lowland jungle strangled with plants and teeming with exotic fauna of all kinds. Recent research coupled with the immense power and widespread availability of satellite imagery reveals that, although generally flat and green, there is astonishing biological and ecological variability. …

The documentation of immense biological variation has done little to change stereotypes of the indigenous occupants of the region—as traditionally small-scale and dispersed villages of ’stone-age primitives’ hidden away in forest clearings. The majority opinion still holds that natural forces and processes, little impacted by human actions until recently, are responsible for the current composition of the region. However, appearances are deceiving and, in this case, the present composition of the region as closed forest often masks an environmental history much more complex.

In-depth studies in ethnohistory and archaeology, i.e. studies with sufficient time-depth to evaluate long-term patterns, clearly document that some areas were home to fairly densely settled, highly productive and powerful regional polities in the past. These small to medium-sized complex societies converted many forests into patchy, managed landscapes, which included fairly large-scale transformations of soils, forest plants and animals, and wetlands.

Regional specialists agree that indigenous populations were decimated by colonialism, making it impossible to sustain the popular viewpoint that indigenous populations have changed little over the past few millennia. Post-contact (1492) population collapse resulted in a wholesale ‘fallowing’ of managed forest landscapes across large portions of Amazonia. Thus, the image of small, ephemeral indigenous groups and only minimal impacts upon the lands they occupied, still widely maintained by many natural scientists, conservationists, policy-makers and the public at large, is no longer tenable as a general characterization of native peoples and must be demonstrated rather than assumed. The time has come to abandon assumptions of uniformity in cultural terms, and recognize that biological and cultural variations are the result of the complex and dynamic histories of coupled human–environmental systems. …

HOTSPOTS THROUGH TIME

The focus on present conditions of nature and human society tends to portray virgin forest, which is then seen as negatively impacted by human use, in particular the dramatic and rapid expansion of Western technology. In a strategically placed advertisement at Boston’s Logan airport (3 October 2003), TNC appears to share this view of a changeless tropical forest in their promotion of efforts to preserve the natural places of the Amazon, “as they were, as they are, and as they always will be.” …
The difficulty of defining such things outside of specific situations is compounded by questions of anthropogenesis: being partially created by humans through secondary succession and ‘intermediate disturbance’ (Balée 2006).

It seems reasonable to suggest that perspectives outside of the natural sciences, i.e. from the social and historical sciences, at least, are required. Contemporary biodiversity is easily measured in terms of the contemporary distributions of plants and animals, as well as the soils, hydrology and other physical features of the land, but cultural landscapes can only be understood historically.

Anthropologists, in particular, due to their ‘grounded’ or participatory approaches, tend to see local socio-historical contexts as critical. From an anthropological viewpoint, several important questions emerge: (i) the incorporation (or lack thereof) of indigenous voices in debates about Amazonian environment, (ii) tensions between local and global considerations, and (iii) the degree to which the actual histories of indigenous peoples are considered. …

The destruction of native lifeways and population collapse is widely accepted throughout the Americas, including Amazonia (Denevan 1976), and archaeology and early ethnohistory show the massive diversity was lost in the wake of colonialism, nation-building and globalization. Indeed, conventional views that small, ephemeral occupations and very few people (0.01–0.3 persons per km2) were fairly ubiquitous in the region–societies that leave only a very minimal footprint on the natural tropical forest (small, short-term clearings)–are generally unsubstantiated historically or archaeologically, beyond a few generations, at the end of a long arduous history of indigenous struggles against hostile invasion. The idea that any sustained human presence, even indigenous peoples with simple tools, is destructive or even invasive of biodiversity, is not only questionable in many cases but also backwards, since it was cultural forces, in significant part, that were responsible for patterns of biodiversity in the first place. Worse yet, by characterizing groups as migratory or transhumant, or even fugitive, who have made no major ‘improvements’ to the land, enables adversaries of indigenous land or cultural rights to deny their claims.

Without in-depth archaeological and historical research it is difficult to be certain what is being measured or how one or another environment has or will respond to human intervention. The discovery of large, settled communities and dense regional populations suggests a much longer and complex history of human use and, by definition, sustainable resource use. It also provides ways to look back in time to see differential use of Amazonian landscapes and the long-term outcomes of land use. Minimally, it can no longer be assumed that an apparent lack of human influences today is an indication that it was always this way. …

Nepstad et al.’s (2005) quantitative analysis of patterns revealed in satellite-based maps strongly shows that “indigenous lands occupy one-fifth of the Brazilian Amazon and are currently the most important barrier to Amazon deforestation.” In other words, indigenous resource management strategies are doing something right and it is worth understanding them, in the present and the past, and preserving them in the future.

BIO-HISTORICAL HOTSPOTS ALONG THE AMAZON RIVER

Archaeology is a critical component in recent discussions as often the only way to understand long-term dynamic change in coupled human–environment systems in tropical forest settings. In Amazonia, it has revealed a very deep and complicated history, extending from the late Pleistocene to today, and showing remarkable change and variability in cultural patterns through time and from region to region. In late prehistoric times, it is widely believed that large pre-Columbian populations managed resources effectively and on a fairly large scale, particularly in major river settings. Several areas along the Amazon River, in particular, have substantial evidence that large, productive economies were common in some parts of pre-Columbian Amazonia, notably river areas where forest farming and wetland management could be intensified. …

By the 1980s, it was widely believed that chiefdoms throughout the Amazon bottomlands, or várzea, associated with the ‘Amazonian polychrome tradition’ that includes Marajoara, depended on fairly intensive exploitation of aquatic resources and diversified cultivation (Lathrap et al. 1985; R. L. Carneiro, 1986, unpublished work). …

Wetland landscape management among Marajoara also appears to include river palms fruits, such as Açai palm (Euterpe oleracea and related Juçara, Euterpe edulis, used today primarily for heart-of-palm; family Arecaceae) and other agricultural crops, including possible indigenous seed crops (Roosevelt 1991; Schaan 2004).

Santarém is a related but distinctive culture concentrated in the region at the confluence of the Amazon and the Tapajós rivers (about 500 km upstream from Marajó), centered on the Brazilian city of the same name. Santarém is an archaeological culture known primarily by its ornate ceramics (see Gomes 2002). …

Roosevelt’s (1999) fieldwork in and around the city of Santarém leads her to believe that the polity was an even more populous and complex chiefdom than Marajó, characterized by intensive floodplain and upland agriculture, and significant impacts in forest and wetland ecologies. …

Based on largely unpublished fieldwork, she estimates that at its peak, in terminal pre-Columbian times, the site extended over an area of nearly 16 km2, although as is typical in other parts of the Amazon, the distribution of occupation areas is likely patchy and spread out over this area. Nonetheless, if correct, her estimate of this late prehistoric capital town rivals the size of Cahokia, the largest site in North America, or many of the stone and adobe temple centres of the central Andes and Mesoamerica. Its size and power are corroborated by diverse references to large settlements, populous regions and large-scale canoe flotillas of warriors in early chronicles of the river (Porro 1996).

Recent research on archaeological dark earth (ADE) soils from a variety of sites in the lower Tapajos River appears to have found the agronomic signature of these large populations (Lehmann et al. 2003; Glaser and Woods 2004; Glaser 2006). ADE research suggests that the area was densely occupied and that agricultural populations had a complex and sophisticated system of ADE creation and management, including both the occupational soils (terra preta) and the non-ceramic bearing agricultural soils (terra mulata; Woods and McCann 1999). Areas of altered (anthropogenic) soils vary from quite small (less than 1 ha) to quite large (more than 100 ha) and occur in a wide range of contexts, and in the Lower Tapajós ADE cover an area of well over a thousand hectares (Denevan 2001; Kern et al. 2003). Diverse techniques of management, including burning, mulching and other techniques are suggested and supported by ethnographic studies, such as Hecht’s (2003) discussion of Kayapó land and soil management and Posey’s (2004) general discussion of ‘forest islands’ (possible archaeological sites as well as integral parts of contemporary resource management) and eco-tone management in the neighbouring middle Xingu River region.

The infrastructural elaboration of Açutuba, including mounds, ramps and ditches, sculpted plazas and agricultural areas, attest to the necessarily great alteration of the tropical forest in this riverine setting. Use of the broad area was highly patchy and variable as people move from place to place, or not, through time. This brings to mind Balée’s (1989, 2006) notion of broad anthropogenic landscapes built up through time, as well as Denevan’s (1992, 1996, 2001) suggestion of intensively used zones around bluff settlements, which he feels was more typical in the past before metal axes. These findings corroborate early ethnohistoric accounts from the middle Amazon River (Porro 1996). …

The PAC [Projeto Arqueológico de Amazônia Central] provides the strongest archaeological evidence to date that the Amazon River bottomlands and adjacent areas were densely populated and some settlements had heavily constructed core areas, including architectural earthworks, massive soil alteration in and around settlements, large agricultural areas and possible wetland management systems. …

THE UPPER XINGU: A HOTSPOT THROUGH TIME

The headwater region of the Xingu River, or Upper Xingu, in northeastern Mato Grosso state, Brazil, provides another clear case of anthropogenic modification of Amazonian landscapes over the long term (see Heckenberger et al. 2003; Heckenberger 2005). The Upper Xingu is one of several areas in the southern Amazon region where densely settled complex societies flourished during the late prehistory. …

Archaeological complexes associated with these groups, including sophisticated agricultural, settlement and road earthworks, have long been known from the eastern lowlands of Bolivia (Denevan 2001). Aerial photography in the mid-twentieth century made it more feasible to visualize the scale and configuration of agricultural earthworks, raised causeways and other features in open savanna. Erickson’s (e.g. 2000, 2001, 2006) recent archaeological work has revealed a complex system of earthworks, including causeways, fish weirs and ponds, and forest islands (ancient settlements), raised fields and diverse other archaeological landscape features. Erickson (2000, p. 193) notes that: ‘Rather than domesticate the species that they exploited, the people of Bauré domesticated the landscape’. Recent research suggests that not only is much of the area anthropogenic, but that biodiversity is equal if not higher in anthropogenic than in nonanthropogenic areas (see Bale´e 2006). …

This raises the question of whether post-European depopulation truncated a pattern of forest conversion that may have been degrading landscapes by late prehistoric times. Certainly in the past there was a greater proportion of non-forested to forested areas, but evidence suggests that sustainable levels of land use were being maintained. In fact, it seems that economic productivity and landscape configuration had coevolved over many centuries, and intensification was carried out by fine-tuning the diverse and patchy orchard, field and garden agricultural areas, as well as by management of wetland fisheries. …

Plaza villages, like today, were critical social nodes and tied into elaborate socio-political networks. Primary roads and bridges are oriented to plazas, or more accurately, are ordered by the same spatial principles, which also order domestic and public space, creating a cartography and landscape that was highly partitioned and rigidly organized according to the layouts of settlements and roads …

FINAL COMMENT: REQUIEM FOR A PRIMITIVE WORLD?

Clearly in the Upper Xingu, like the other areas discussed, a new concept, distinct from traditional conceptions of biodiversity, must be developed, which includes biocultural diversity—looking at the way certain cultural and biological patterns are mutually constituted—and bio-historical diversity, for lack of a better term, to describe how this process unfolds over the long term.

The realization that Amazonia is not a land of primitive peoples and pristine nature, untouched until quite recently, does not imply that indigenous societies are similar to contemporary (Western) society. What is interesting is how native peoples developed through time in unique ways, organizing themselves and the natural world through complex cultural relations with nature and sophisticated technologies through which to manipulate or manage the natural environment, rather than ‘tame’ it. …

That Amazonian landscapes are richly historical and constructed makes them no less natural or interesting, or tainted in terms of biodiversity. Many aspects of indigenous and folk resource management provide ready-made alternatives to imported and far more destructive development strategies and technologies. As Laurance et al. (2001, p. 439) suggest: ‘Rather than rampant exploitation, an alternative and far superior model for Amazonian development is one in which agricultural land is used intensively rather than extensively and ‘high-value’ agroforestry is valued and perennial crops are favoured over fire-maintained cattle pastures and slash-and-burn farming plots.’ Indeed, this is precisely what it seems some indigenous groups were doing. Indigenous practices limit deforestation and lasting partnerships between indigenous and rural peoples in the region will maintain standing forests and potentially even restore tropical forest degradation (Lamb et al. 2005; Nepstad et al. 2005). …

[A]s a hotspot in terms of genes, species and the overall ecosystem(s), as well as in terms of local, national and world heritage, issues of human agency, dynamic change in coupled human–environmental systems and human rights loom large in questions of conservation or sustainable development. In this regard, understanding indigenous systems of management, including those that are only or largely apparent archaeologically, may hold critical keys to future approaches to land use and land rights.

Tuesday, December 23, 2008

Making Primitive Biochar

Those who have followed my blog know that I proposed a method for producing biochar that was plausible inside the limitations placed on an antique society living in the Amazon rainforest. Key to the time and place was the use of maize as the principal source material. That this was so was confirmed by published pollen studies and by more recent translations of sixteenth century reports from southern Brazil which described widespread maize culture.

When I began my thought experiment, the presence of maize seemed very unlikely in view of the known dynamics of rainforest soils. Yet I needed a plant that produced packable waste that could be handled without steel tools. Wood was both high cost in human energy inputs and very resistant to charring and crushing. Most other crops simply failed to produce both a crop and much biomass. No primitive farmer was going to plant a stand-alone char feedstock and lose a season.

This is where corn or maize came in. It produced a stable easy to store high volume crop that also produced perhaps ten tons per acre of corn stover. This stover was also very packable because there are no branches. What made it more attractive was the root ball which is in the form of a disc and is often very easy to pull out of the soil. Thus a field could be stripped of its ripe corn and then stripped easily of its stover.

Stacking the stalks was easily accomplished and using the root balls to form an outer wall simply a matter of paying attention. The key idea was to provide an outer shell of mud that closed off the packed stover. Now they did not have a sheet of metal foil to add another heat resistant air tight layer, so it is likely that they slathered on a thin layer of river clay to form a air tight seal. Again field experiments will inform us as to the extent that this is all necessary.

At the end of the day, without any tools, we have a thin clay dome or a mud dome enclosing ten tons of packed stover.

This is then loaded with a charge of burning coals. I have considered top down but suspect that simply feeding a charge in through the bottom perhaps along a narrow trench will be good enough. A small amount of air will be drawn to the charge maintaining the heat production and the produced heat will steadily reduce the maize very quickly. Gasses will be captured and ignite as the burn progresses steadily reducing the load.

Eventually the whole load will collapse upon which it will be smothered with more dirt.

I had originally envisaged this process taking many hours, however corn stover is like paper and merely needs to be heated for it to curl up and quickly decompose.

Ten tons or one acres production would give us three tons of biochar which is ample for that one acre, particularly if one goes the extra step of creating seed hills on only a third of the surface. In one season, you are in business. The one remaining mystery is why this method failed to make it out of the Amazon, because it would have nicely augmented the three sisters throughout the Americas. Or perhaps it did and we simply never noticed or our steel got there first and disease got there first.

Monday, December 8, 2008

Biochar by Lisa Abend

A recent revelation for me on biochar was the understanding that it was the advent of the steel axe that made slash and burn practical. Prior to that, the Indios would need to maximize the fertility and productivity of any land that was cleared and maintained for their livelihood.

This is a well written recent article on the subject that nicely covers the development to date. My long time readers will note that more and more reports of trials around the globe are popping up with impressive success.
In fact we have yet to see a serious setback anywhere, although some ruined soils are slower to respond to the treatment as could be expected.

This all means that global fertility and productivity of soils in place are going to increase substantially over the next twenty years as we master the methodology.

It is also worth saying that the naysayers are fading and that the scientific explanation that I was one of the first to proffer eighteen months ago is slowly working into the ongoing debate. That the role of the carbon as a solid crystalline acid is to grab and hold nutrients is not obvious yet that is what happens.

My knowledge of that allowed me to immediately accept terra preta, since I had made the conjecture that activated charcoal would be as good as zeolites as a soil additive. A decade earlier I had reviewed work done by Cuba on zeolites and that had led to a review of an article in Scientific American on solid crystalline acids that tied it all together and led to the conjecture.

Doing anything about it was impossible because of the long lead times associated with implementing new agricultural methodology. I was thus delighted to discover the work on terra preta eighteen months ago and am equally delighted to watch the rapid progress it is now making around the globe.

There is nothing like a two thousand year field trial in the middle of the worst soils on earth to run off the regulatory crowd.

I would like to see many more documentaries and I would like to do one in which we simulate production methods using primitive techniques and even minimal farm equipment. I have written a lot on that subject.

World - Carbon: The Biochar Solution

Lisa Abend

On his farm in the hills of west virginia, Josh Frye isn't raising chickens just for meat. He is also raising them for their manure. Through a process that some scientists tout as a solution to climate change, food shortages and the energy crisis, Frye is transforming the waste into a charcoal-like substance called biochar that in the long run could be far better for the world than chicken nuggets. "It might look like this is just a poultry farm," says Frye. "But it's a char farm too."

Burn almost any kind of organic material — corn husks, hazelnut shells, bamboo and, yes, even chicken manure — in an oxygen-depleted process called pyrolysis, and you generate gases and heat that can be used as energy. What remains is a solid — biochar — that sequesters carbon, keeping CO2 out of the atmosphere. In principle, at least, you create energy in a way that is not just carbon neutral, but carbon negative.

And the benefits only begin there. When added to thin and acidic soil of the kind found in much of South America and Africa, char produces higher agricultural yields and lets farmers cut down on costly, petroleum-heavy fertilizers. Subsistence farmers seeking better soil have traditionally relied on slash-and-burn agriculture, which generates greenhouse gases and decimates forests. If instead those farmers slow-smoldered their agricultural waste to produce charcoal — in effect, slash-and-char agriculture — they could fertilize existing plots instead of clearing more land. This in turn would reduce emissions in the atmosphere, and so on in a virtuous circle of environmental renewal.

Could it really be that simple? It appears to have been for the original inhabitants of the Amazon basin. In the 16th century, Spanish explorer Francisco de Orellana wrote home describing the remarkably fertile lands he had discovered there. In the 19th century, American and Canadian geologists uncovered the reason: bands of terra preta (dark earth), which locals continued to cultivate successfully. Research revealed that the original inhabitants of the region had added charred wood and leaves — biochar — to their lands.

Centuries later, it was still there, enriching the soil. "You couldn't help but notice it. There would be all this poor, grayish soil, and then, right next to it, a tract of black that was several meters deep," says Johannes Lehmann, a soil scientist who worked in Manaus, Brazil, in the late 1990s. After he left the Amazon in 2000 for a job at Cornell University, N.Y., Lehmann started wondering what would happen if farmers today could make their own terra preta. He has found one answer in a field trial in Kenya, where 45 farmers achieved twice the yield in their corn crops with biochar than with conventional fertilizers.

Epidra, a private firm in Athens, Ga., is exploring larger-scale applications, such as pyrolysis systems that can produce both enough energy to power a tractor and a biochar tailored to improve particular soils. "If you're going to grow food, you have to do it responsibly," says Bob Hawkins, Eprida's project manager. "And one way of doing that is to use it to generate sustainable energy." A prototype can turn a ton of ground peanut shells into 600 lb. (270 kg) of biochar, with energy as the bonus.

Biochar's ability to sequester CO2 has given new urgency to such research. "Reducing emissions isn't enough — we have to draw down the carbon stock in the atmosphere," says Tim Flannery, chair of the Copenhagen Climate Council, a consortium of scientists and business leaders linked to next year's United Nations Climate Summit. "And for that, slow pyrolysis biochar is a superior solution to anything else that's been proposed." Cornell's Lehmann is even more emphatic. "If biochar could be massively applied around the globe," he says, "we could end the emissions problem in one to two years."

Not everyone agrees. "Biochar isn't a silver bullet, not by a long shot," says Dominic Woolf, a researcher at Swansea University in Wales. "You have to look at the big picture: pyrolysis itself produces carbon dioxide emissions, and you have to consider that when you try to determine biochar's capacity for sequestration." Lehmann says he welcomes the doubts, and notes that addressing them requires "investors willing to take the risk." Which is where chicken farmer Frye, with his small biochar operation, comes in as one of the few people out there actually making a business of it. With a pyrolysis unit that can create 3-4 tons of biochar a day, he generates enough energy to heat his hen houses; and he sells the char as fertilizer for $600 a ton. For Lehmann, biochar's benefits aren't so much a scientific novelty as a return to basics. "From cave drawings to iron smelting, charcoal has always played an important role in the development of civilization," he says. "Maybe it's about to do it again."

Tuesday, August 26, 2008

Biochar Review and A.D.Karve Postings

A.D. Karve is an active contributor to the terra preta list and is a botanist by training. His observations and experiments are well worth reviewing. I have extracted a number of his postings on the subject of biochar.

It may be too early to suggest that a consensus currently exists, but it is fair to say that opinion is converging on several key points.

1 Biochar and by inference terra preta is typically produced in the mid temperatures (plus and minus around 350 degrees Fahrenheit). Production at other higher temperatures is also officious with less residual. It is produced primarily from non woody plant waste in order to provide a fine carbon powder with maximum yield in the all critical surface area. Wood charcoal is just as useful after crushing but normally has a fuel market and is diverted.

2 The powdered charcoal acts as a catalytic sponge for free ions in the soil. The use of the word catalytic is a bit unfair since all we expect is that the receptor sites in the charcoal will grab a free ion and hold it until such time as a biological agent removes it. However, it does get the idea across and I am hardly the first to overuse this word. This mechanism retains nutrients in the working soil while preventing nutrient loss through leaching.

3 The evidence to date suggests that this goes far beyond a mere retention usage. It appears to facilitate the rapid reconstruction of a high quality soil base even in wasted lands and even hostile soils with little remaining organic content. This was unexpected but it appears that we are going there. It is now possible to suggest that it is possible to construct a rich fertile soil many inches deep starting in the middle of the desert in a time span of perhaps twenty years. This is an apparently wild claim but every thing that I have seen combined with our limited knowledge earned to date supports this conjecture.

4 This actually makes total sense. The retention of nutrients particularly nitrogen, allows organic material to be reduced with a limited loss into the atmosphere as CO2. The soil can then be manufactured swiftly.

5 To date every problem soil this has been tried on has eventually generated positive results including land ruined by excess salinity. That is the most important problem where irrigation has wreaked the soils over thousands of years. In fairness, we are still in early days. In fact the work cited here is as good as it gets to date. However, we are approaching the point were hundreds and thousands will start working with these precepts.

6 The char is easily produced by either an earthen kiln, not unlike that used for indigenous charcoal making with waste wood, or the simple expedient of a sheet metal drum set on a bed of sticks to provide limited air flow with a lid to control the fire started on top of the charge. None of this is elegant but is will produce a satisfactory yield while disposing of all the farm waste at little new cost.

7 It is very easy to wax enthusiastic on this subject when a five thousand year field trial conducted by the Indios in Brazil supported a civilization of millions on the worst tropical soils ever. The reason it never found its way into other areas was simply that these other areas never produced enough plant waste to make a noticeable difference. Today that is easily solvable. I have posted on corn stover and bagasse as feedstocks. And the wood chipper is also producing a viable feedstock for the satisfactory production of biochar. Modern equipment will allow us to use our ingenuity to reduce all agricultural and woodland waste to biochar without an excessive expense.

8 It is a reasonable conjecture that the application of powdered charcoal to soils will eliminate the majority of fertilizer wastage now producing oceanic dead zones. It will also quickly reduce the need for fertilizer to vastly lower levels.

9 Vast tracts of well watered tropical and semi tropical lands are very suitable for this technology as well as those lands already been exploited for agriculture. Thus before any effort is expended on more arid lands, it appears that we can expect a massive increase in agriculture in these areas. For starters, the multi year slash and burn cycle will disappear forever.

10 I have accepted a long soil gestation cycle as a reasonable assumption. In fact there is no evidence to suggest that is the case. The first application of biochar should establish good production if not immediately, certainly by the next season as the soil responds. Ten to twenty years of continuous cropping and biochar application should produce a thick rich soil that then requires no further biochar. Field trials may end this process a lot sooner. The remote fields of the Indios were named terra mulato because the charcoal content was present but visibly lower but still significant. I do not have a grade yet, but since one initial season of corn culture can produce respectable carbon content (one to two tons per acre) it is very possible that the direct manufacture of a remote field was a one time effort that paid off for years.

The one point that we should recognize is that all other soils will also need extensive field testing before the local advisory agencies can get fully behind its universal implementation. It is not that we already know the answers – we do – it is just that a field test establishes best local practice and any noteworthy anomalies. Even after all that is said, every farmer will want to run his own test plot in order to both see the results on his ground but also to learn methodology. The good news, is that we are now approaching this threshold of activity.






Dear List,
a former colleague of mine conducted a study of the slash and burn agriculture in the Western Ghats mountain range in India. The farmers generally cultivate a plot for about 5 years. Every year the yield is lower than in the previous year. The plot is abandoned after 5 years becasue the yield is down to unacceptably low level. Weeds, wild herbs and grasses take over the ababdoned land. Some woody plants also establish themselves in this plot of land. After a fallow period of about 10 years, the vegetation on the land is again destroyed by slashing and burning and the land is again brought under cultivation. My colleague conducted soil analysis before and after every crop, and he found that the soil analysis did not change over the five year period of cultivation, and yet the yield dropped every year. He explained this phenomenon by the fact that it was not the soil fertility that diminished over the years, but that the soil was washed away by heavy rains and also because the land sloped. Thus, at the end of the fifth year, hardly a couple of inches of soil was left in the field.
Yours


Dear List,
soil micro-organisms need the same elements as green plants. In soils that are phosphate deficient, the phosphate solubilizing bacteria have a distinct advantage over others because they have the ability to get phosphorus out of phosphatic compounds that are normally insoluble and therefore not available to organisms in the soil. Whenever one applies an organic nutrient compound to the soil, the soil micro-organisms multiply by feeding on the organic nutrient, which primarily provides them with carbon. The mineral ions and molecules are obtained by them from the soil solution. But if the soil solution is deficient in phosphorus, application of an organic nutrient to the soil would automatically lead to a selective increase in the population of phosphate solubilizing bacteria, because only the PSB have the ability to multiply in such soils. Two of my students are currently conducting experiments to test if this hypothesis is correct.
Yours

Dear Mr.Astrupgaard,
when I used the word carbon source, I meant food containing carbon. Please note that nobody can use charcoal as food. The green plants use carbon dioxide as their carbon source. The non-photosynthetic organisms use digestible organic substances like carbohydrates, organic acids etc. as their carbon source. So rotting vegetation and compost also form a part of their food. The nitrogen fixing bacteria need energy to fix nitrogen, to conduct their own metabolism and also to multiply. This energy comes from the carbon in the food that they consume. The carbon gets converted into carbon dioxide in this process. That is why they all, including all animals, need a carbon source in the form of an easily digestible organic compound. As long as they live, the N-fixing organisms do not give the nitrogen fixed by them to any other organism, but use it in their own metabolism and reproduction. The molecules and ions (nitrogen, phosphorus, potash, iron, boron, etc.) in their cells become available to other organisms only when they die. Animals generally need ready made proteins, fats, vitamins etc. for survival. The micro-organisms generally need only a good source of carbon like sugar or a polysaccharide. They can synthesize their own proteins, vitamins etc. using inorganic salts containing the essential minerals.
Yours

Dear Sean,
the azotobacter are free living bacteria and as long as they have a carbon source available to them, they go on multiplying and utilizing the fixed nitrogen for their own metabolism and reproduction They die when the carbohydrates and other sources of carbon available to them are exhausted. In fact that is the basis of my application of 25 kg sugar per ha to the soil once every three months. The sugar increases the number of micro-organisms in the soil, and when the sugar is exhausted, they die. The nutrients released from the dead cells become available to the green plants. The nitrogen fixing microbes do not provide nitrogen to others as long as they are living. The case of rhizobium is altogether different. They are held captive in the root nodules and work like a part of the plant itself. They are fed by the green plants and the green plants extract amino acids from them. In the case of cyanobacteria, the ntrogenous compounds are stored in special perennating organs called heterocysts. Even when the Cyanobacteria die, the heterocysts survive in the dry soil as propagules, from which the next generation of cyanobacteria arises the next year. I am not saying that phytohormones can substitute nitrogenous fertilizers. I was only trying to explain the 10 to 15 % higher yield that is recorded whenever the cyanobacteria are applied to rice fields and I also gave my interpretation of the ecological significance of why the Cyanobacteria promote the growth of rice. There are enough reports in literature of 10 to 15% yield increase caused by substances like triacontanol (a C30 alcohol), organophosphatic insecticides, etc. which have growth promoting effect. Even urea spreayed as 2% solution gives similar effect. It is not caused by the nitrogen in the urea but it is due to the growth stimulating effect of urea.
Yours


Dear List,
there is a school of thought that believes that the free living nitrogen fixing organisms do not give any nitrogen to other organisms, Fixing atmospheric notrogen requires huge expenditure of energy (e.g. look at Haber-Bosch process). When an organism spends that much energy on fixing atmospheric nitrogen, why should it give it to other organisms? In India, cyanobacteria are recommended to be applied to rice fields. There are enough data to show that this treatment causes about 10 to 15% yield increase in rice. Assuming that the cyanobacteria do not give nitrogen to rice, but that they promote growth of rice through plant growth promoting substances, I conducted experiments in which I germinated seeds of barley in a culture filtrate of cyanobacteria and demonstrated that such a filtrate did actually have plant growth promoting property. The plant growth promoting property of cyanobacteria was demonstrated by us even in the case of kidney beans and wheat. Most of the growth promoting substances work at concentrations of 5 to 10 p.p.m. Therefore, plant growth promoting substances are used in quantities that can be measured in grams per hectare, whereas nitrogen being a fertilizer chemical is required in kilogram quantities. So, if the soil micro-organisms want the green plants to grow more vigorously, it makes sense for them to exude phytohormones into their environment than lose to the environment the nitrogen fixed by them so laboriously. It costs them much less energy to produce phytohormones. The question now arises as to why the microbes should promote the growth of green plants. As far as the cyanobacteria in rice paddies are concerned, if the rice plants developed a thick canopy, the growth of green algae would be restricted, because the photosynthetically active radiation would be absorbed by the leaves of rice. Thus, by promoting the growth of rice, the cyanobacteria eliminate the competition from green algae. In the case of other plants, the bacteria may be getting more sugar or more root exudates if the green plants grew more vigorously.
Yours

Dear Martin,
I really do not know, how much char is to be applied per hectar. But I can tell you how to make char out of your burnable organic waste. The simplest device is a top-lit updraft kiln. It consists of a vertical cylinder, having relatively small holes near its base for primary air. You fill the cylindrical body of the kiln with the material to be charred and then light it from the top. Once the fire gets going, you place a lid on the cylinder. There is a chimney built into the lid. The lid does not sit flush on the kiln, but there is a gap between the lid and the kiln. The draft created by the chimney sucks secondary air into the chimney, where it gets mixed with the pyrolysis gas to burn it. The biomass burns downwards, leaving a layer of charcoal on top. As the primary air comes upwards, it meets the burning front which traverses downwards. The burning biomass utilises all the oxygen in the primary air, so that the air going up through the layer of char has only carbon dioxide, carbon monoxide, nitrogen and the pyrolysis gas left in it. As there is no oxygen left in the updraft air, it cannot burn the char that has formed above the burning biomass.The pyrolysis gas and carbon monoxide burn in the chimney, because of the secondary air that is sucked in through the gap between the chimney and the kiln. You have to find out by trial and error, how long it takes to char the material loaded in the kiln. After that much time is over, you remove the lid, and extinguish the fire by sprinkling water over the burning material. This particular device is portable and manually operated. There are larger charring kilns, based on the oven and retort process. Prof. Yuri Yudkevich, a Russian scientist, has made them for charring useless material generated by the timber industry in Russia. We are already using both types of kilns under field conditions in India for charring agricultural waste as also urban waste. We have a video CD that describes the kilns and you can fabricate them by watching the video CD. I have not used Prof. Antal's kiln and have absolutely no idea how it operates. Our web site
www.arti-india. org would show you how to get our CDs by paying us through Pay Pal.

Molasses do have some minerals in them, but the idea that I am propagating is, that one provides the soil microbes only with a carbon source and that they take up the rest of the minerals from the soil solution. I had mentioned in a previous communication, that the water of guttation of many plants contained sugar (e.g. sorghum) or organic acids (e.g. chickpea). Water of guttation is the water oozing out from the leaves during the night. I had already mentioned that the amount of minerals dissolved in the soil solution has a constant value depending upon the solubility of the concerned mineral. Therefore, when the micro-organisms remove the mineral molecules and ions from the soil solution, they are replaced by more of the molecules and ions getting dissolved in the soil solution in order to maintain the equilibrium. When the carbon source has been exhausted, the micro-organisms die, releasing the minerals sequestered in their cells. The green plants and the microbes need the same mineral elements. Therefore when the micro-organisms die, the minerals released from their cells become available to the plants. This symbiosis between the soil microbes and green plants evolved when the green plants came out of the sea and occupied land. Aphids seem to be a part of this symbiosis, because they suck out sugar from the green plants and exude it out of their bodies. The water of guttaion washes off this sugar and drops it on the ground. The fact that plants drop their leaves and flower petals on the ground can also be looked upon as a part of this symbiotic relationship, because these organs feed the soil micro-organisms. It is a known fact that most of the useful minerals are retracted by the plants from the leaves before they are shed. I am trying to mimic the behaviour of the plants in order to develop techniques of growing crops without using chemical fertilizers.
Yours

Dear Greg,
Most of the reactions on externally applied organic matter take place in the top layer of the soil and they are therefore aerobic. Alcohol is formed under anaerobic conditions. Sugar is directly ingested as food by most micro-organisms and it is used by them as carbon source. In the case of plants and also most micro-organisms in the soil, almost 95 per cent of the weight is constituted by carbon, hydrogen, oxygen and nitrogen, all of which are obtained from air. Only 5% come from minerals in the soil. These minerals are absorbed from the soil solution. Whenever an organinc substance with high nutritive value is applied to the soil it causes the number of micro-organisms in the soil to increase. When the carbon source has been exhausted, the microbes die, releasing the sequestered mineral ions and molecules back into the soil solution, making them available to the plants. This is of course just a hypothesis, on which I am working. Literally thousands of farmers are applying today unrefined raw sugar to their fields at the rate of 10 kg per acre or 25 kg per ha, once every 3 months. They are getting good yield from their crops. I am only trying to find out the scientific reason behind this phenomenon.
Yours

Dear Mr. Haard,
ploughing in green plants is called green manuring. It provides soil micro-organisms with high calorie nutrition. In the normal green manuring practice, the green crop is grown on the entire field and ploughed in, after about 45 days. Because of the availability of a carbon source in such abundance, the microbes multiply very fast and take up and bind all the minerals in the soil solution in their own cells. Then you wait for at least a month before planting your crop, becasue otherwise your crop would not get any mineral nutrients from the soil. After a month, a part of the microbes are dead and have released the mineral molecules back into the soil. You therefore lose about 45 days in growing the green cover and another month in allowing it to rot in the soil, Green manuring is therefore not popular with farmers, because they lose a complete season. Under rainfed cropping in India, it means losing the entire year. That is why I recommend applying just 125 kg green leaves per ha along with the seed. While the seedlings are growing, he microbes multiply their numbers by eating the leaves, but because the leaves have been applied in just a small quantity, the nutrition is exhausted very fast by the soil microbes and they start to die, releasing the nutrients sequestered in their cells. By this time, the crop plants have developed their own root system and they are ready to absorb these nutrients. This is just a hypothesis. All that I have observed is that I get high yield whenever I apply about 125 kg green leaves per ha to my crop, right at the beginning of the season. I am trying to find out how and why this practice works so beneficially.
Yours


Dear Mr. Haard,
this refers to your request about my reaction to the observations of Dr. Makoto Ogawa. I am a botanist who used to work as the Research Director of a seed company in India. I worked mainly in the fields of plant physiology and plant breeding. I am now 72 and I head a voluntary organization founded by me for rural development through application of science and technology. I was made aware of the topic of Terra Preta by Ron Larson and Tom Miles and so I became a member of the Terra Preta discussion group. I developed interest in this topic because I had developed some theories of my own about plant nutrition, and agriculture without the use of chemical fertilizers. In the course of my research I found that by feeding the soil bacteria with high calorie, non-composted organic matter such as sugar, starch or cellulose, one not only increased the number of the soil microbes but also the yield of the crops. Just to test my hunch, I applied just 125 kg green leaves to a hectare of land owned by me, and got higher yield from this land than I used to get by applying chemical fertilizers. Now I have started a series of pot experiments in which the pots containing 1 kg soil each received 500 mg sugar, no sugar and a dose of chemical fertilizers. The pots are kept in a randomized complete block design, so that the data can be statistically analysed. After I started talking to my colleagues about charcoal being added to soil, some of them applied char made from sugarcane leaves to plants raised in pots and they reported that the plants in pots with char grew better than the ones not receiving this treatment. These experiments were not conducted very scientifically and they should be treated as anecdotal evidence.

Realising, that I did not know anything about soil science, I recently purchased a book on this subject and have started reading it. Although this book makes reference neither to Terra Preta nor to plant nutrition, the knowledge about soil minerals, their genesis and their metamorphosis under different climatic conditions is helping me greatly in understanding many aspects of plant nutrition. I feel that this knowledge would eventually be useful to me also in understanding Terra Preta. When I gain an insight into this topic, I shall certainly share it with this group.
Yours