Monday, July 09, 2007

Origins of Amazonia's Terra Preta Soils

I have been convinced for some time that the Terra Preta soil in any given location is far more than just black carbon supplementation derived from slash and char techniques. I believe, based on my research of online source material on Terra Preta that each patch of Terra Preta soil (there are hundreds, even thousands of such sites known throughout Amazonia and more being discovered each day) has been seeded with Terra Preta soil from another (previous) location. I believe these Terra Preta soils have their origins in the first agricultural efforts on carbon-rich volcanic soils in northwest South America (Ecuador and Bolivia) as land migration into South America from Central and North America by ancient indigenous peoples proceeded.

I am guilty, as are most, of focusing my research on garnering support for my theory and, consciously or subconsciously, rejecting that which does not support it. That having been said, however, I do believe there is a preponderance of research material that is supportive. Following are a number of pertinent quotes from source material that I believe bolsters my position.

Terra preta soils "....contain microbes that are uniquely associated with soils high in BC as compared to adjacent soils....."[1]
There is "....a greater homology between sequences obtained from the four TP sites than between sequences obtained from adjacent and non-TP soils from the same site."[1]
Scientists are having difficulty in developing answers to the Terra Preta mystery. There remain "....many questions still unanswered with respect to their origin, distribution, and properties."[2] Additionally, "....Thus far, despite great effort, scientists have been unable to duplicate production of the soil."[3] The realistic conclusion of the researchers is, "....At the moment, there is a lot of excitement but there’s a lot of work to do.”[3]
Despite many consistencies in Terra Preta soils at different sites, the native characteristics of the altered soil result in many "....varied features of the dark earths throughout the Amazon Basin."[2]
The differences in carbon content in Terra Preta soils suggests that it is not natural in that "....the total carbon stored in these soils can be one order of magnitude higher than in adjacent soils."[2]
The structural similarity of the carbon in Terra Preta soils to charcoal has consistently led researchers to assume that the ".....purposeful application of organic carbon from incomplete combustion may have been the primary reason for the high carbon contents....."[2]
Terra Preta soils have tremendously high fertility. Researchers claim "....terra preta can increase yields 350 percent over adjacent, nutrient-leached soils."[3] Also note, however, that "Amazonian dark earths have high carbon contents that are five to eight times higher than the surrounding soil...."[4]
In a practice that may mimic the original development of widely dispersed Terra Preta soils, "Truckloads of the dark earth are often carted off and sold like potting soil."[3]
A clue to one key aspect of Terra Preta soil is scientific belief that, " residues are an important portion of the high phosphorus concentrations. Phosphorus is really the number one limiting nutrient in the central Amazon."[3] This suggests that the original development of Terra Preta soil may have occurred closer to the sea, on the northwest coast of South America, rather than in Amazonia.
An important key to the uniqueness of Terra Preta soil and, I believe, an important indicator that it may have been seeded from previous sites, is contained in this statement. "You can have the same amount of carbon in terra preta and adjacent soils and the infertile soil won’t change."[3]
Philip Coppens reveals one of the most salient points supporting seeding when he states "....most now argue that people altered the soil with a transforming bacterial change."[4]
One of the most tantalizing clues that the development of Terra Preta soils may have accompanied the gradual populating of the Americas is contained in this statement, "....though science may have long forgotten about this technique, in the highlands of Mexico, these techniques can still be seen at night, when local farmers set parts of their field alight."[4]
Finally the tantalizing question of Terra Preta soil's ability to reproduce itself is revealed in this statement. "In fact, one missing ingredient is how the soil appears to reproduce. Science may not know the answer, but the Amazonian people themselves argue that as long as 20cm of the soil is left undisturbed, the bed will regenerate over a period of about twenty years. A combination of bacteria and fungi are believed to be the transformative agents, but the agents themselves remain elusive from the scientific microscopes."[4]
1) Isolating Unique Bacteria from Terra Preta Systems: Using Culturing and Molecular Tools for Characterizing Microbial Life in Terra Preta
2) Terra Preta de Indio
3) Terra preta: unearthing an agricultural goldmine
4) Terra Preta - Philip Coppens


Philip Small said...

Appreciate your post. Terra preta is certainly among the more exciting recent developments in the realm of soil science. In my opinion, only the more recent (1995) discovery of glomalin comes close to TP in importance.

It is good to get excited about this, but it is a complex subject. I perceive that the TP we see today went through several stages of development, several regime changes in soil biota, and over a long period of time. Note for instance the 1-2 meter depth of translocated black char in TP. That takes time.

Adding charcoal to soil can initially stimulate growth of fungi, as established by Japanese research. Mycorrhizal fungi can produce increasingly recalcitrant carbon levels in soil (through glomalin), and reach deep into the soil for limiting phosphorus. It can enhance root function in disease protection and soil water management. But fungi activity is limited by increasing soil pH levels. Continuing additions of charcoal would increase soil pH which would decrease soil fungi activity in favor of bacteria.

I sense that, with the limited biomass handling capabilities of the pre-columbian population, that gradual change in Amazonian soil character was the order of the day. My abductively reasoned minor-char/high-fungi stage would have been prolonged, and quite important in providing the increased biomass productivity that encouraged continued, and eventually, more aggressive, additions of char. I speculate that this did not occur before the fungi were able to leave their signature of elevated phosphorus content in the surface soil, an effect enhanced by soils increased ability to retain nutrients, a key benefit of char.

Progressive change in dominant soil biota is in the nature of soil. Human intervention and the development of a unique soil biotic community and transplanting it to other soil may be a factor in TP phenomena, but it is not a necessary one. Soil does this routinely.

All soil seems to have some charcoal in it. 10 to 35% of soil organic carbon in Australian and USA soils are charcoal. I assume this occurs the world over. Char-C builds up slowly over time because, unlike other forms of soil organic C, it is not subject to decomposition within 10 years. Even glomalin lasts only 10 years at best.

The self-replicating nature of terra preta is certainly intriguing, but may not stand up entirely to closer scrutiny.

The effect is not just from charcoal. That affect seems limited to the soil-reef structure of char that protects microorganisms, and possibly some unknown bio-catalytic effect that char-C may have. But much of the effect of char is separate from these. Much of the increase in productivity can be attributed to the pH-altering nature of charcoal on acidic soils and the P-K-S-Ca nutrients provided in the food processing kitchen scraps used to make the core terra preta.

My understanding is that terra mulata, the lighter colored and less kitchen-midden-affected version of TP, TM is the more extensive version of Amazonian Dark Earths (ADE) that TP grades into. It is the TP+TM in combination that accounts for 10%+ of the amazon basin, a fact that might be important to some, it is seldom detailed in the popular texts.

Apologies for uncharacteristically long comment.

Anonymous said...

Hi All,
The Tool We need for TP & The Chemistry of Energy in MIT's Technology Review.

July/August 2007

Metagenomics Defined
Genomics will help explain the microbial world.
By Ed DeLong

"Conventional genomic research on micro├Ârganisms determines the DNA sequences of individual microbes by examining cultivated strains. In metagenomics, DNA sequence information is extracted from entire microbial communities in situ."

"The ­majority of extant microbial species and their behaviors therefore represent a vast biological terra incognita. Meta­genomic approaches, which sidestep the need to purify and cultivate individual microbial strains, make it easier to retrieve genome sequence information from elusive microbial species. A second, and perhaps more important, point is that microbial species do not generally occur as single strains or pure cultures. Rather, any given microbial assemblage can consist of hundreds of different species, each one displaying significant genetic variability. The biological meaning and functional consequences of this tremendous within- and between-species biodiversity remain obscure. Metagenomic approaches enable direct assessment of community diversity and provide data sets relevant to both measuring and modeling biological processes."

"The study of anthropogenic effects on microbial processes that regulate the mass balance of planetary carbon and nitrogen cycles will also benefit from metagenomics."


A Q&A with;
George Whitesides ,The chemistry of energy

He hints all around the problems that TP seems to solve. I plan to send him my TP links

Erich J. Knight
Shenandoah Gardens
1047 Dave Berry Rd.
McGaheysville, VA. 22840
(540) 289-9750
shengar at

erich said...

All the Bio-Char Companies and equipment manufactures I've found:

Carbon Diversion

Eprida: Sustainable Solutions for Global Concerns

BEST Pyrolysis, Inc. | Slow Pyrolysis - Biomass - Clean Energy - Renewable Ene

Dynamotive Energy Systems | The Evolution of Energy

Ensyn - Environmentally Friendly Energy and Chemicals

Agri-Therm, developing bio oils from agricultural waste

Advanced BioRefinery Inc.

Technology Review: Turning Slash into Cash

3R Environmental Technologies Ltd. (Edward Someus)

The company has Swedish origin and developing/designing medium and large scale carbonization units. The company is the licensor and technology provider to NviroClean Tech Ltd British American organization WEB: and VERTUS Ltd.

Genesis Industries, as the current licensee of Eprida technology, provides you with a carbon negative Eprida energy machine at the same cost as going direct to Eprida. Through our technical support staff we also provide you with the information to obtain the best utilization of the biocharcoal that is produced by the machine. Recent research has shown that Eprida charcoal can increase plant productivity as it sequesters carbon in the soil, thus helping reduce atmospheric carbon dioxide.

Mycorrhizae Inoculent;

The International Biochar Initiative (IBI) conference held at Terrigal, NSW, Australia in 2007. The papers from this conference are posted at their home page;


If pre-Columbian Kayopo Indians could produce these soils up to 6 feet deep over 15% of the Amazon basin using "Slash & CHAR" verses "Slash & Burn", it seems that our energy and agricultural industries could also product them at scale.

Harnessing the work of this vast number of microbes and fungi changes the whole equation of energy return over energy input (EROEI) for food and Bio fuels. I see this as the only sustainable agricultural strategy if we no longer have cheap fossil fuels for fertilizer.

We need this super community of wee beasties to work in concert with us by populating them into their proper Soil horizon Carbon Condos.

Erich J. Knight
Shenandoah Gardens
1047 Dave Berry Rd.
McGaheysville, VA. 22840
(540) 289-9750