Atlantis Online
June 30, 2022, 03:11:42 pm
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Satellite images 'show Atlantis'
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Superdirt Made Lost Amazon Cities Possible?

Pages: [1]   Go Down
Author Topic: Superdirt Made Lost Amazon Cities Possible?  (Read 172 times)
Superhero Member
Posts: 41646

« on: November 22, 2008, 05:11:41 pm »

Three Kuikuro Indians pose for documentary filmmakers in 2008 in Brazil's Xingu Indigenous Park, a remote Amazon Basin refuge for traditional cultures.

The Kuikuro tribe is said to be among the last to have seen British explorer Col. Percy Fawcett, who in 1925 led an ill-fated quest for a fabled lost Amazonian city.

The idea that the region hosted ancient cities is gaining ground in the 21st century, due in part to studies
of an ancient man-made soil, which may have provided the food necessary for such a civilization.

Photograph copyright
Phil Day / Edge West, LLC
« Last Edit: November 22, 2008, 05:20:30 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.

Share on Facebook Share on Twitter

Superhero Member
Posts: 41646

« Reply #1 on: November 22, 2008, 05:18:04 pm »

                                       Superdirt Made Lost Amazon Cities Possible?

John Roach
for National Geographic News
November 19, 2008

Centuries-old European explorers' tales of lost cities in the Amazon have long been dismissed by scholars, in part because the region is too infertile to feed a sprawling civilization.

Now scientists are trying to recreate the recipe for the apparently human-made supersoil, which
still covers up to 10 percent of the Amazon Basin. Key ingredients included of dirt, charcoal, pottery, human excrement and other waste.

If recreated, the engineered soil could feed the hungry and may even help fight global warming,
experts suggest.

Before 1492

Scientists have long thought the river basin's tropical soils were too acidic to grow anything but the hardiest varieties of manioc, a potatolike staple.

But over the past several decades, researchers have discovered tracts of productive terra preta—"dark earth." The human-made soil's chocolaty color contrasts sharply with the region's natural yellowish soils.
« Last Edit: November 22, 2008, 05:24:45 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #2 on: November 22, 2008, 05:26:40 pm »

Left - a nutrient-poor oxisol;

right - an oxisol transformed into fertile terra preta

                                                     T E R R A   P R E T A

From Wikipedia, the free encyclopedia

Terra preta (“dark earth” in Portuguese) refers to expanses of very dark, fertile anthropogenic soils found in the Amazon Basin. It owes its name to its very high charcoal content. It is also known as “Amazonian dark earth” or “Indian black earth”. In Portuguese its full name is “Terra preta do índio” or “Terra preta de índio”. Terra mulata is lighter or brownish in color.

Terra preta is characterized by the presence of low-temperature charcoal in high concentrations; of high quantities of pottery sherds; of organic matter such as plant residues, animal faeces, fish and animal bones and other material; and of nutrients such as nitrogen (N), phosphorus (P), calcium (Ca), zinc (Zn), manganese (Mn).

It also shows high levels of microorganic activities and other specific characteristics within its particular ecosystem. It is less prone to leaching than surrounding soils. Terra preta zones are generally surrounded by terra comum, or "common soil"; these are infertile soils, mainly acrisols, but also ferralsols and arenosols

Terra preta soils are of pre-Columbian nature and were created by man between 7000 BP (ca. 5000 BC) and 500 BP (ca. 1450 AD) ("Before Present"). The soil's depth can reach 2 metres (6 feet). Thousands of years after its creation it is reputedly known as self-regenerating at the rate of 1 centimetre per year by the local farmers and caboclos in Brazil's Amazonian basin, and they seek it out for use and for sale as valuable compost.
« Last Edit: November 22, 2008, 05:31:17 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #3 on: November 22, 2008, 05:37:41 pm »



For a long time, the origins of the Amazonian dark earths were not immediately clear and several theories were considered. One idea was that they resulted from ashfall from volcanoes in the Andes, since they occur more frequently on the brows of higher terraces. Another theory considered its formation as a result of sedimentation in Tertiary lakes or in recent ponds.

However, because of their elevated charcoal content and the common presence of pottery remains,
it is now widely accepted that these soils are a product of indigenous soil management involving a labor intensive technique termed slash-and-char. The technique is differentiated from slash and burn by a lower temperature burn (thus producing more charcoal than ashes) and in being a tool for soil improvement.

This type of soil appeared between 450 BC and AD 950 at sites throughout the Amazon Basin.

The Spanish explorer Francisco de Orellana, the 16th C explorer who was the first European to transverse the Amazon River, reported densely populated regions running hundreds of kilometers along the river, suggesting population levels exceeding even those of today. These populations left no lasting monuments because they used local wood as their construction material, which unfortunately rotted in the humid climate (stone was unavailable).

While it is possible Orellana may have exaggerated the level of development among the Amazonians, their semi-nomadic descendants have the odd distinction among tribal indigenous societies of a hereditary, yet landless, aristocracy, a historical anomaly for a society without a sedentary, agrarian culture.

This suggests they once were more settled and agrarian but after the demographic collapse of the
16th and 17th century, due to European-introduced diseases, they reverted to less complex modes
of existence but maintained certain traditions.

Moreover, many indigenous people were forced to adapt to a more mobile lifestyle in order to protect themselves against colonialism. This might have made the benefits of terra preta, such as its self-renewing capacity, less attractive — farmers would not have been able to enjoy the use of renewed
soil because they would have been forced to move for safety.

Slash-and-burn might have been an adaptation to these conditions.

For 350 years after the European arrival by Vicente Yáńez Pinzón, the Portuguese portion of the
basin remained an untended former food gathering and planned agricultural landscape occupied
by the Indigenous peoples who survived the arrival of European diseases.

There is ample evidence for complex large-scale, pre-Columbian social formations, including chiefdoms, in many areas of Amazonia (particularly the inter-fluvial regions) and even large towns and cities.

For instance the pre-Columbian culture on the island of Marajo may have developed Social stratification and supported a population of 100,000 people.

The Native Americans of the Amazon rain forest may have used Terra preta to make the land suitable for the large scale agriculture needed to support large populations and complex social formations such as chiefdoms.
« Last Edit: November 22, 2008, 05:47:11 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #4 on: November 22, 2008, 05:41:34 pm »



Terra Preta soils are found mainly in Amazonia, where Sombroek et al estimate that they cover at
least 0.1 to 0.3%, or 6,300 to 18,900 km˛ of low forested Amazonia (cited by Denevan and Woods);
but others estimate this surface at 1.0% or more (twice the surface of Great-Britain).

Plots of Terra preta exist in small surfaces averaging 20 hectares, but near-900 acres' surfaces have also
been reported.

They are found among various climatic, geological and topographical situations.

Their distribution either follows main water courses, from East Amazonia to the central basin of Ama-
zonia[9], or are located on interfluvial sites (mainly of circular or lenticular shape and of a smaller size averag-
ing some 1.4 ha), see also distribution map of Terra Preta sites in Amazon basin.

Williams W. Woods (soil biologist at Southern Illinois University) estimates that around 10% of the original terra comum appears to have been converted to Terra preta. According to William Balée (anthropologist at Tulane University in New Orleans), the spreads of tropical forest between the savannas could be mainly anthropogenic –
a notion with dramatic implications world-wide for agri-
culture and conservation.

Terra preta sites are also known in other South American areas (Ecuador, Peru, Guyana)[13], in West Africa
(Benin, Liberia), and on the South African savannas.

Similar soil was found in late Roman Britain - see dark earth.
« Last Edit: November 22, 2008, 05:49:35 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #5 on: November 22, 2008, 05:53:42 pm »


Terra Preta is defined as a type of latosol, having a carbon content ranging from high to very high
(more than 13-14% organic matter) in its A horizon, but without hydromorphic characteristics.

The composition of Terra preta presents important variants. For instance, the gardens close to dwell-
ings received more nutrients than fields farther away.

The variations in Amazonian dark earths prevent from establishing a clear separation line on whether they were intentionally created for soil improvement or whether the lightest variants are a by-product of habitation.

The varied features of the dark earths throughout the Amazon Basin suggest the existence of an extensive ancient native civilization dating back 500 to 2500 years bp.

Terra preta's capacity to increase its own volume – thus to sequester more carbon – was 'discovered' by pedologist William I. Woods of Southern Illinois University Edwardsville.  This central mystery of
Terra preta, is actively studied by many researchers from various disciplines.

The processes responsible for the formation of Terra preta soils are:

Incorporation of wood charcoal

Incorporation of organic matter and of nutrients

Role of micro-organisms and animals in the soil
Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #6 on: November 22, 2008, 06:01:33 pm »

Wood charcoal

The transformation of biomass into charcoal produces a series of charcoal derivates covered under the name of pyrogenic or black carbon, the composition of which varies; from lightly charred organic matter, up to soot particles rich in graphite formed by recomposition of free radicals (Hedges et al. 2000).

Here, all types of charbonated materials are called charcoal.

By convention, charcoal is considered to be any natural organic matter thermically transformed with
an O/C percentage less than 0.6[16] (smaller values have been suggested).

Because of possible interactions with minerals and organic matter from the soil, it is almost impossible
to identify charcoal with any certainty by determining only the proportion of O/C. The H/C percentage[18] or molecular markers such as benzenepolycarboxylic acid[19], are therefore used as second level
of identification.

Charcoal was added to poor soils, as wood charcoal processed at low temperature and with a limited supply of oxygen (i.e., with smothered fires).

William Woods (University of Kansas, Lawrence), expert on (ancient) abandoned living sites, has measured in Terra preta up to 9% black carbon (against 0.5% in surrounding soils). B. Glaser et al have found up to 70 times more carbon than in surrounding Ferralsols[3], with approximative average values of 50 Mg ha-1 m-1.

Amending the soil with low temperature charcoal produced from a mix of wood and leafy biomass (termed biochar) has been observed to increase the activity of arbuscular mycorrhizal fungi.

Finnish researcher Janna Pietikäinen has tested high porosity materials such as zeolite, activated carbon and charcoal; these tests show – contrary to her expectations - that microbial growth is substantially improved with charcoal. It may be so that these small pieces of charcoal tend to migrate within the soil, providing a habitat for bacteria that decompose the biomass in the surface ground cover. It is theorized that this process may have an essential role in Terra preta soils' self-propagation; a virtuous cycle would be established as the fungus spreads from the charcoal, fixing additional carbon, stabilizing the soil with glomalin, and increasing nutrient availability for nearby plants.  Many other agents contribute, from earthworms to humans and the charring process.

The chemical structure of charcoal in Terra preta soils is characterized with poly-condensed aromatic groups, providing prolonged biological and chemical stability that sustains the fight against microbial degradation; it also provides, after partial oxydation, the highest nutrients retention.

Wood charcoal (but not that from grasses or high cellulose made at low temperature), thus has an internal layer of biological oil condensates that the bacteria consume, and that is similar to cellulose in its effects on microbial growth (Christoph Steiner, EACU 2004).

Charring at high temperature loses that layer and brings little increase in the soil fertility. Glaser et al. (1998 and 2003) and Brodowski et al. (2005) have proved that the formation of condensed aromatic structures depends on the manufacture of charcoal. It is the slow oxidation of charcoal that creates carboxylic groups; these increase the cations' exchange capacity in the soil.

Lehmann et al have studied the nucleus of black carbon particles produced by the biomass. They have found it highly aromatic even after thousands of years in the soil and presenting spectral characteristics of fresh charcoal. Around that nucleus and on the surface of the black carbon particles, there were higher proportions of forms of carboxylic and phenolic Cs spatially and structurally distinct from the particle's nucleus. Analysis of the groups of molecules provides evidences both for the oxydation of the black carbon particle itself, as well as for the adsorption of non-black carbon.

This charcoal is thus decisive for the sustainability aspect of Terra preta soils.

Amendements of Ferrasol with wood charcoal greatly increases vegetal productivity.

Note that agricultural lands have lost in average 50% of their carbon due to the practice of intensive cultivation and other degradations of human origin.

It is important to note that the fresh charcoal must first be “charged” before it can function as a bio
tope.  Several experiments demonstrate that uncharged charcoal can bring a provisional depletion of available nutrients when first put into the soil - until its pores fill up with nutrients. This is overcome
by soaking the charcoal for a few weeks (2 to 4 weeks) in any liquid nutrient (urine, plant tea. ...).
Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #7 on: November 22, 2008, 06:12:23 pm »

                                                  Organic matter and nutrients

      Charcoal's porosity brings a better retention of organic matter, of water and of dissolved organic

         nutrients, as well as of pollutants such as pesticides and aromatic poly-cyclic hydrocarbons.

Organic matter

The high absorption potential of organic molecules (and of water) is due to the porous structure
of charcoal.

The Terra preta soils, containing these great quantities of charcoal, are equally characterized by a
high concentration of organic matter (on average three times more than in the surrounding poor soils, up to 150 g/kg.

Organic matter can be found at 1 to 2 metre deep.

Gerhard Bechtold proposes to call "Terra Preta" the soils that show, at 50 cm depth, a minimum proportion of organic matter superior to 2.0 or 2.5%. The accumulation of organic matter in moist tropical soils is a paradox, because of optimum conditions for degradation.  It is remarkable that these anthrosols regenerate in spite of these tropical conditions' prevalence and the fast mineralisation rates. It has been demonstrated that the stability of organic matter is mainly due to the biomass being only partially consumed.


Terra preta soils also show higher quantities of nutrients, and a better retention of these nutrients,
than the surrounding infertile soils. The proportion of P reaches 200-400 mg/kg. The quantity of N is also higher in anthrosol, but that nutrient is immobilized because of the high proportion of C over N in the soil.

The anthrosol's availability of P, Ca, Mn, and Zn is clearly higher than the neighbouring Ferrasol. The absorption of P, K, Ca, Zn, and Cu by the plants increases when the quantity of available charcoal increases. The production of biomass for two crops (rice and Vigna unguiculata (L.) Walp.) increased
by 38-45% without fertilization (P < 0.05), compared to crops on fertilized Ferrasol.

Amending with pieces of charcoal approximately 20 mm in diameter, instead of ground charcoal, did not change the results of experience except for manganese (Mn), for which absorption considerably increased.

Nutrient drainage is minimal in this anthrosol, despite their abundant availability, resulting in high fertility. When inorganic nutrients are applied to the soil, however, the nutrients' drainage in anthrosol exceeds that in fertilized Ferralsol.

As potential sources of nutrients, only C (via photosynthesis) and N (from biological fixation) can be produced in situ. All the other elements (P, K, Ca, Mg, a.s.o.) must be present in the soil. In Amazonia the approvisionning in nutrients from composting in situ is excluded for natural soils heavily washed-out (Ferralsols, Acrisols, Lixisols, Arenosols, Uxisols, ...) that do not contain these elements in high concentration. In the case of Terra preta, the only possible nutrient sources are primary and secondary.

The following components have been found:

Human and animal excrements (rich in P and N);

Kitchen refuse, such as animal bones and tortoise shells (rich in P and Ca);

Ash residue from incomplete combustion (rich in Ca, Mg, K, P and charcoal);

Biomass of terrestrial plants (e.g. compost); and

Biomass of aquatic plants (e.g. algae).

Saturation in pH and in base is more important than in the surrounding soils (Sombroek, 1966; Smith, 1980; Kern and Kämpf, 1989; Sombroek et al., 1993; Glaser et al., 2000; Lehmann et al., 2003;
Liang et al., 2006).
Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #8 on: November 22, 2008, 06:16:55 pm »

Microorganisms and animals

Bacteria and fungi (myco-organisms) live and die within the porous media, thus increasing its carbon content. Johannes Lehman and W. Zech, Bruno Glaser ŕ l'Universite de Bayreuth (Allemagne), Embrapa (Manaus, Brazil)
and many others, are studying these phenomena.

Until now there is no scientific evidence for a particular micro-organism to be responsible for the formation of
Terra Preta, but a significant production of biological black carbon has recently been identified, especially under moist tropical conditions.

It is possible that the fungus Aspergillus niger is mainly responsible for it.

Topoliantz and Ponge's work, summarized in a synthetic article in “Soil Biology & Biochemistry”, shows that the peregrine earthworm Pontoscolex corethrurus (Oligochaeta: Glossoscolecidae), widespread in
all Amazonia and notably in clearings after burning processes thanks to its high tolerance of a low content of organic matter in the soil, has been shown to ingest pieces of charcoal and to mix them in
a finely ground form with the mineral soil.

The authors, who experimentally verified this process, point at this as an essential element in the generation of Terra preta soils, associated with agronomic knowledge involving layering the charcoal in thin regular layers favourable to its burying by Pontoscolex corethrurus.

Some ants are repelled from fresh Terra Preta soils, their density of appearance is found to be low after about
10 days as compared to control soils – see Terra Preta Experiments.

Modern research to recreate Terra preta

Efforts to recreate these soils are being undertaken by companies such as Biochar Energy Corporation, Eprida
and Best Energies.

Research efforts are underway at Cornell University, the University of Georgia, Iowa State University and Geoecology Energy Organisation.

Biochar is the main (and likely key) ingredient in the formation of terra preta. One focus of these researchers is
the prospect that if biochar becomes widely used for soil improvement, it will involve globally significant amounts
of carbon sequestration, remediating global warming.

See also



Dark earth

Russian Chernozem

Terramare culture

1491: New Revelations of the Americas Before Columbus
« Last Edit: November 22, 2008, 06:19:12 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Superhero Member
Posts: 41646

« Reply #9 on: November 22, 2008, 06:21:44 pm »


"“1491”"., by Charles Mann.

"Eprida Home Page". Retrieved on 2006-05-08.

"Programme Summary: The Secret of El Dorado". BBC Two, 9 pm, Thursday 19 December 2005. Retrieved on 2008-07-10.

"Terra Preta". Hypography discussion forum. Retrieved on 2006-05-08.

"Putting the carbon back: Black is the new green" (PDF). Nature. Retrieved on 2008-07-10.

"Terra Preta Discussion List". Retrieved on 2008-07-10.

Bechtold,G.: "Research work, homepage and thesis about Terra Preta with maps of TP sites and TP
field work in Belterra, Pará".

Michael Tennesen (2007). "Black Gold of the Amazon", in Discover Magazine Vol. 28 No. 04, April 2007. Last accessed March 2007.

"Terra Preta Home Page". Retrieved on 2007-04-20.

David Haywood (2007). "Could the Mysterious Agricultural Techniques of an Ancient Amazonian Civilization Make New Zealand Farming More Competitive?", on Public Address Radio 5 May 2007.
Last accessed May 2007.

Casselman, Anne (May 2007). ""Special Report: Inspired by Ancient Amazonians, a Plan to Convert
Trash into Environmental Treasure"". Scientific American. Retrieved on 2008-07-10.
Manuel Arroyo-Kalin (2007) Geoarchaeological approaches to the study of Terras Pretas.

External links

"Modern Terra Preta Creation".
Salleh, Anna (2007-06-08). "Charred farm waste could gobble up carbon". News in Science.
Australian Broadcasting Corporation. Retrieved on 2008-07-10. ABC Science Online.

Horstman, Mark (2007-09-23). "Agrichar – A solution to global warming?",
ABC TV Science: Catalyst, Australian Broadcasting Corporation.
Retrieved on 10 July 2008. 

Retrieved from ""
Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Pages: [1]   Go Up
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy