Amazonian terra preta soil can transform poor soil into fertile

[JohnyCanuck]

Amazonian terra preta soil can transform poor soil into fertile, reports Dwain Eldred

Here is a type of gold the conquistadores missed – black gold: some of the globe's richest soil that can transform poor soil into highly fertile ground.

Scientists have developed a method to reproduce this soil – also known as Amazonian dark earths - and say it can pull substantial amounts of carbon out of the Earth's atmosphere, and so help prevent global warming. That's because terra preta is loaded with so-called "bio-char" - similar to charcoal.

What is Terra Preta?

Terra Preta (do indio) is a black earth-like anthropogenic soil with enhanced fertility due to high levels of soil organic matter (SOM) and nutrients such as nitrogen, phosphorus, potassium, and calcium embedded in a landscape of infertile soils. Terra Preta soils occur in small patches averaging 20ha, but 350ha sites have also been reported. These man-made soils, often over 2000 years old, occur in the Brazilian Amazon basin and other regions of South America such as Ecuador and Peru but also in Western Africa (Benin, Liberia) and in the savannas of South Africa. Terra Preta soils are very popular with the local farmers and are used especially to produce cash crops such as papaya and mango, which grow about three times as rapid as on surrounding infertile soils.

"The knowledge that we can gain from studying the Amazonian dark earths, found throughout the Amazon River region, not only teaches us how to restore degraded soils, treble crop yields and support a wide array of crops in regions with agriculturally poor soils, but also can lead to technologies to sequester carbon in soil and prevent critical changes in world climate" says Johannes Lehmann, assistant professor of biogeochemistry in the Department of Crop and Soil Sciences at Cornell University, speaking at the 2006 meeting of the American Association for the Advancement of Science.

http://www.geolsoc.org.uk/template.cfm?name=TerraPreta

[TallahasseeGrannie]

1. Good Lord. Good news!

Don't know if I ca handle it!

[xchrom]

2. the ancients still teaching us a thing or three.

they don't say which groups created the terra petra.

it would be interesting to know.

[dcfirefighter]

3. There are several 'modern' methods for this

I practice 'biointensive' gardening in my back yard. More than anything, it is a method for improving soil characteristics through crop choice and composting.

It's proponents advise that within a few years, any patch of soil that gets 10"+ of rain during the growing season can be made quite fertile: A year's food for one person can be grown on 5,000 s.f. with a four month growing season. Compare this to commercial petrochemical agriculture, which would require not only oil imputs, but at least four times the land area.

It is information like this that lets me know that the world isn't over populated, but rather the world's resoruces are poorly allocated.

[Oerdin]

4. Terra Preta.

Read the book 1491 (about life in the Americas before the European arrival) to get a better feel of what terra preta is. The big problem with tropical soils is that most of their nutruites get leached out of the soil by the massive amounts of rain water and that cleared land normally gets its soil compacted by the constant pounding of rain which produces a hard pan in 3-4 years after a plot has been cleared. Terra preta is different from traditional composts because it contains a lot of half burned wood pieces in it. The charcoal bonds wit much of the nutruites preventing them from being washed away while the rest of the compost makes a nice growing climite for various bacteria and other life forms like worms thus producing soil that is very fertile but also retains fertility over time unlike naturally occuring soils.

Next comes the part which many leftist get their panties into a bunch over. Assuming the natives made this compost then that means vast sections of the Amazon forest used to be orchards and garden plots of the natives and the majority of the forest is less then 500 years old. Terra preta covers that much of the Amazon basin. Then there is the question of why does so much of the Amazon consist of trees which produce fruits which humans find yummy? Anwser: The natives who produced all that terra preta were growing something while the main domesticates ntive to the Amazonia region were palms and fruit trees so the natives spent thousands of years clearing undesirable trees and planting vast orcharids to provide them with fruit. Indeed whole native cities existed in the Amazon but European diseases exterminated most of the urban population just like it did in the lower Mississippi basin.

People like to say the Amazon is ancient or "primeval" but it is looking like some where between 40%-60% of it has been very heavily influenced by man long before Europeans ever showed up. In short the natives were busy terra forming the place and turning it into something more suited to their life style and to their benifet. That pretty much kills the myth that natives "lived in harmony with nature" (the reality is like all other people they were not in harmony; look up the pleistocene mass extinction) and it does show that in just a few hundred years a previously very domesticated Amazonia has returned as a second growth forest.

[midnight armadillo]

5. wait a minute...

That pretty much
kills the myth that natives "lived in harmony with nature" (the reality
is like all other people they were not in harmony; look up the
pleistocene mass extinction)

This means that 'Ishmael' is a big steaming heap of dung! LOL.

There are many other examples of human intervention in landscapes - agriculture being the most obvious one. The Native Americans that the Pilgrims encountered routinely did deliberate burns of undergrowth in the eastern MA forests, if my memory serves me.

The permaculture concept of a 'food forest' is certainly not a modern innovation, given the evidence from the Amazon.

[Buzz Clik]

6. Your memory is correct.

Fire has been a management tool in many setting and helps maintain the original vegetation. A perfect example is the tallgrass prairie in the Midwest. Periodic burns kept the prairies and prairie grasses lush and kept out unwanted shrubs and weedy trees. Proper controlled burns today achieve the same goal.

[Oerdin]

14. The natives of noth America and Australia.

Routinely and deliberately set large fires to burn underbrush over vast areas. Doing so increased the amount of open grasland which large herbavores feed on thus increasing the food supply for native hunters. This works very well if you are a hunter but it is a major impact upon the ecology. There was no noble savage living in harmony with nature. There was just another group of people doing their best to modify the earth in order to make their lives a bit more comfortable. Let's give up on the old "lived in harmony" myth.

[Odin2005]

7. Yep, the "noble savage" living in harmony with nature is all nonsense.

Even hunter gatherers change the enviroment by fire and by "managing" land in a way that could be considered "proto-agricultural" (land management is beleived to be one of the reasons we out-competed the Neandertals, since they just hunted and gathered whatever they ran into, and therefore used resources less efficiently than we did). This is why I don't like this "natural is good, artificial is bad" attitide some have, all organisms modify the enviroment in some way, a high-rise building is fundimentally the same thing as a prairie dog tunnel system, the only difference is in scale. It is overpopulation and wastefullness that is bad for the enviroment, not development per se. To make artificial things is as natural for to us as making tunnels is to prairie dogs

[Buzz Clik]

8. Some disagreement here....

Perhaps it's just your wording: "That pretty much kills the myth that natives "lived in harmony with nature" (the reality is like all other people they were not in harmony...)"

Take a look a the depth of the terra preta soil from the link given in the opening post of this thread. That soil is roughly 2 feet (60 cm) deep. To obtain soils that deep would take hundreds of years at a minimum. Cultivating the soil and either maintaining its original depth (i.e., no erosion) or building it up is not only living in harmony with nature, it's actually giving back to the natural process. Considering that these soils occur in areas 20 to 350 ha in size, this is truly amazing an amazing feat.

Reasonable ecologists/environmentalists recognize that humans cannot inhabit a landscape without impacting it. However, if they don't destroy it but actually improve it, that's truly impressive.

[XemaSab]

9. "if they don't destroy it but actually improve it?"

This implies that nature can be improved upon. :shrug:

Also, in response to the OP, my understanding is that in tropical ecosystems, most of the nutrients present in the system are in the standing biomass and not the soils. So where did the "extra" nutrients come from in these smaller patches?

If you're burning the forest to create a milpa, nutrients are both volatilized and left susceptible to leaching, and the vegetation that colonizes the site is left to make do with what's left after the burn. So unless they were importing high-nutrient materials, I don't understand where the extra nitrogen and potassium are coming from.

It's been theorized that the Mayans, among others, destroyed their civilization by practicing slash and burn agriculture. So what did the Mayans do wrong that these other groups did right? :shrug:

(edit: bad spelling)

[htuttle]

11. Q: Extra nutrients origin? A: One word, brown in color, sounds like a bell

Dung!

On the subject of harmony with nature, I think there are a lot of misconceptions about what that means, and where humans fit in. Humans are, in fact, part of nature. We have as much "right" to live here as any other species. We're 'allowed' to kill stuff and eat it, like any other species, and also 'allowed' to do moderate 'terraforming' like ants, beavers, any burrowing mammal, earthworms, etc...

The key is in the word 'harmony', ie., BALANCE. Sustainability. "Permaculture" is a nice modern word for what used to come more naturally (though not really consciously -- we lacked the means to get TOO far out of balance before modern technology).

I'd wager that what the Mayans did wrong, if slash and burn agriculture did in fact destroy their civilization, was that they probably got greedy, like we are. We're likely headed the same direction.

In a way, even our 'unnatural' state right now is somewhat 'natural'. Environmental and geological changes have occasionally thrown bioregions (or even the whole Earth) out of balance for awhile. Sooner or later, the 'greedy species' has it's population cut back, often as a direct result of it's overpopulation. We aren't the first species to make this mistake. We're probably the first species on Earth to do this while being actually being aware of it, however. That's just stupidity, I guess (and hubris).

[Odin2005]

13. Slash and Burn works fine for small populations...

...but as the population grew they didin't find a more sustainable form of agriculture, which is why the Maya civilization collapsed. The problem is, that with our current population no method of farming can both feed humanity and be sustainable. Genetic engineered crops and permaculture-based methods will help a good bit, but ultimately we need to reduce our population if we want to get back in balance.

[Oerdin]

15. You're wrong.

Most of the compost is formed by collecting biological material (brush,wood, animal bones, human waste), half burning most of it and then mixing it into the soil along with large quantities of broken pottery. The clay in the pottery expanded and contracted in the wet vs dry periods helping to loosen the soil and counter act the compacting force the pounding of rain has on the soil. You can build up this type of compost very quickly in fields as long as you keep bringing in new material to add to the compost. The only written account we have, written by Spaniards who sailed from Peru to Brazil in the 16th century, recounts natives doing exactly that. They also observed very large native settlements, with large populations, earthen mound (religious structures which served a cerimonial position for the native elites), canals, and a sophicated system of dikes used to channal flood waters way from the towns/cities. It was 150 years before the next group of Europeans reached the area and by then old world diseases had wiped out Amazonia's urban centers just as they had done to the urban centers in the lower Mississippi.

We are not talking about people living in harmony and instead we are talking about masses of people totally clearing forests (with just fire and stone tools) and terra forming it into something they found more useful. Old growth forests were wiped out and replaced by native agriculture. It was a remarkable feat and shows a low tech solution to a problem which even modern farmers face in tropical areas.

[NickB79]

12. The timeframe for the transformation was likely much slower though

The native Amazonians didn't clearcut 50% of the Amazon basin in a few decades, like we are currently doing. They most likely cleared small areas at a time, improving the soil for years, and then moved on to another small patch. Eventually the Amazon would have looked like much of the Eastern US does today: patches of forest interspersed with patches of farmland. This would explain why the terra preta patches are usually only 20-350 hectares in size. It would also make a substantial difference on the ability of nature to adapt to the changes. By "nibbling" away at the edges of the Amazon over centuries, it gives species time to relocate further into the forest, or to adapt to the new growth favored by humans. This would allow the best of both worlds; still maintaining a diverse species assortment in the remaining forest, while supporting millions of Amazonians. In fact, as in the Eastern decidious forests of the US, these patchworks would probably increase species diversity, as edge habitat is almost always the most species-diverse area.

[Oerdin]

16. No

You don't get the rise of large towns and cities complete with the cerimonial public works which we know existed in Amazonia based upon the small scale temperary farming model. You get it only via large scale perminent agriculture. What makes terra preta so great is it was a solution to the poor soils found in tropical areas and enabled perminent agriculture instead of the temporary agriculture which presisted after disease destroyed the urban centers. Since the only domesticated animal the natives of Amazonia had was the dog most of the fertiler used to create the compost would have been human waste, animal remains (bones, skins, and internal organs the people didn't eat), and partially burned green materials.

Figuring out that charcoal bonded with nutrients and prevented them from being leached from the soil was a key way to prevent soil depletion in the tropics. The kicker was the massive amounts of pottery which helped to loosen the soil and prevent it from compacting into hard pan which previously stopped perminent agriculture in the tropics. This is what enabled large scale and perminent settlements to form. Sadly, modern archiologists didn't recognize this civilization for a long time because 1) they didn't build stone structures (that's how we found the Mayan & Khamer lost cities which had been over grown by jungles) 2) they didn't have metal and instead used mostly wood, bone, and other biodegradable materials which wouldn't last 500 years), and it is difficult to tell if earth mounds are natural or man made. Brazilian archiologists have really started looking into this in recent decades though so they've found massive amounts of pottery and the remains of earth structures including dikes (used to control the seasonal flooding common in Amazonia), irrigation canals (channals irrigation water during the dry season), and religious monuments (used by the elite to show the common people the gods support the city's rulers).

We're talking about a true lost civilization who radically changed the Amazon and we're also talking about the Amazon easily recovering from a period of massive human explotation and modification.

[NickB79]

17. I think I didn't speak clearly enough

I was agreeing with you on pretty much every point in your original post. I was just pointing out that it likely took them many generations to carry out the intense modifications to the land that they did, far slower than we are doing today with chainsaws and bulldozers. By saying they cleared an area of land, worked it to terra preta, and moved on, I meant that they kept working their original fields and moved on to new land to expand their fields, not slash-and-burn as is common today.

My only point was that it likely took them far longer to alter the Amazon than we are doing today, and that the alterations were less drastic than converting forest to grazing land. Thus, the local species likely had more time to adapt and/or migrate away from the encroaching terra preta fields, in contrast to the current levels of species extinction occurring today.

[Oerdin]

18. OK, sorry.

I misunderstood. I thought you were talking about slash and burn but I know see you were not. Sorry.

[papau]

10. Great Post - DO CHAR--AND DO NOT BURN - seems a simple idea!

http://www.css.cornell.edu/faculty/lehmann/biochar/Biochar_home.htm

Bio-char
Soil Biogeochemistry
Johannes Lehmann

Bio-char: the new frontier

Inspired by the fascinating properties of Terra Preta de Indio, bio-char is a soil amendment that has the potential to revolutionize concepts of soil management. While "discovered" may not be the right word, as bio-char (also called charcoal or biomass-derived black carbon) has been used in traditional agricultural practices as well as in modern horticulture, never before has evidence been accumulating that demonstrates so convincingly that bio-char has very specific and unique properties that make it stand out among the opportunities for sustainable soil management.

The benefits of bio-char rest on two pillars:
1- The extremely high affinity of nutrients to bio-char
2- The extremely high persistence of bio-char

These two properties (which are truly extraordinary - see details below) can be used effectively to address some of the most urgent environmental problems of our time:
1- Soil degradation and food insecurity
2- Water pollution from agro-chemicals
3- Climate change

"Soils with bio-char additions are typically more fertile, produce more and better crops for a longer period of time."

THE TWO PILLARS OF BIO-CHAR PROPERTIES

Nutrient Affinity
All organic matter added to soil significantly improves various soil functions, not the least the retention of several nutrients that are essential to plant growth. What is special about bio-char is that it is much more effective in retaining most nutrients and keeping them available to plants than other organic matter for example common leaf litter, compost or manures. Interestingly, this is also true for phosphorus which is not at all retained by 'normal' soil organic matter.
Reading:
Sombroek, W., Nachtergaele, F.O. and Hebel, A.: 1993, ‘Amounts, dynamics and sequestering of carbon in tropical and subtropical soils', Ambio 22, 417-426.
Mikan, C.J. and Abrams, M.D.: 1995, 'Altered forest composition and soil properties of historic charcoal hearths in southeastern Pennsylvania', Canadian Journal of Forestry Research 25, 687-696.
Lehmann, J., da Silva Jr., J.P., Steiner, C., Nehls, T., Zech, W. and Glaser, B.: 2003a, ‘Nutrient availability and leaching in an archaeological Anthrosol and a Ferralsol of the Central Amazon basin: fertilizer, manure and charcoal amendments', Plant and Soil 249 , 343-357.
Lehmann, J., Kern, D.C., German, L.A., McCann, J., Martins, G.C. and Moreira, A.: 2003b, ‘Soil Fertility and Production Potential', in J. Lehmann, D.C. Kern, B. Glaser and W.I. Woods (eds.), Amazonian Dark Earths: Origin, Properties, Management , Dordrecht, Kluwer Academic Publishers, pp. 105-124.


Persistence
It is undisputed that bio-char is much more persistent in soil than any other form of organic matter that is commonly applied to soil. Therefore, all associated benefits with respect to nutrient retention and soil fertility are longer lasting than with alternative management. The long persistence of bio-char in soil also make it a prime candidate for the mitigation of climate change as a potential sink for atmospheric carbon dioxide. The success of effective reduction of greenhouse gases depends on the associated net emission reductions through bio-char sequestration. However, a net emission reduction can only be achieved in conjunction with sustainable management of biomass production. During the conversion of biomass to bio-char 50% of the original carbon is retained in the bio-char, which offers a significant opportunity for creating such a carbon sink.
Reading:
Pessenda, L.C.R., Gouveia, S.E.M. and Aravena, R.: 2001, ‘Radiocarbon dating of total soil organic matter and humin fraction and its comparison with 14 C ages of fossil charcoal', Radiocarbon 43 , 595-601.
Seifritz, W.: 1993, ‘Should we store carbon in charcoal?', International Journal of Hydrogen Energy 18 , 405-407.
Schmidt, M.W.I. and Noack, A.G.: 2000, ‘Black carbon in soils and sediments: analysis, distribution, implications, and current challenges', Global Biogeochemical Cycles 14 , 777-794.
Shindo, H.: 1991, ‘Elementary composition, humus composition, and decomposition in soil of charred grassland plants', Soil Science and Plant Nutrition 37 , 651-657.

Bio-fuel production through low-temperature pyrolysis
"Combining bio-energy production with bio-char application to soil offers one of the most exciting perspectives of future land-based production technologies."

other Groups that are very active in exploring bio-char as a soil amendment through greenhouse and field experiments (not comprehensive, please excuse any important omissions):

- Marco Rondon: Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia

- Bruno Glaser: Institute of Soil Science, University of Bayreuth, Germany

- M. Ogawa: Kansai Research Institute, Japan

- Danny Day, Christoph Steiner: EPRIDA, Athens, GA, USA (www site)

- Stephan Haefele: International Rice Research Institute (IRRI), The Phillippines

http://www.innovations-report.de/html/berichte/geowissenschaften/bericht-55516.html

[jeffreyi]

19. Might have somethng to do w/ this

http://tinyurl.com/33dy5