Skip to comments.Reproducing the Amazon's black soil could bolster fertility and remove carbon from atmosphere
Posted on 02/18/2006 10:15:42 PM PST by Moonman62
ST. LOUIS -- The search for El Dorado in the Amazonian rainforest might not have yielded pots of gold, but it has led to unearthing a different type of gold mine: some of the globe's richest soil that can transform poor soil into highly fertile ground.
That's not all. Scientists have a method to reproduce this soil -- known as terra preta, or Amazonian dark earths -- and say it can pull substantial amounts of carbon out of the increasing levels of carbon dioxide in the Earth's atmosphere, helping to prevent global warming. That's because terra preta is loaded with so-called bio-char -- similar to charcoal.
"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, triple 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," said Johannes Lehmann, assistant professor of biogeochemistry in the Department of Crop and Soil Sciences at Cornell University, speaking today (Feb. 18) at the 2006 meeting of the American Association for the Advancement of Science.
Lehmann, who studies bio-char and is the first author of the 2003 book "Amazonian Dark Earths: Origin, Properties, Management," the first comprehensive overview of the black soil, said that the super-fertile soil was produced thousands of years ago by indigenous populations using slash-and-char methods instead of slash-and-burn. Terra preta was studied for the first time in 1874 by Cornell Professor Charles Hartt.
Whereas slash-and-burn methods use open fires to reduce biomass to ash, slash-and-char uses low-intensity smoldering fires covered with dirt and straw, for example, which partially exclude oxygen.
Slash-and-burn, which is commonly used in many parts of the world to prepare fields for crops, releases greenhouse gases into the atmosphere. Slash-and-char, on the other hand, actually reduces greenhouse gases, Lehmann said, by sequestering huge amounts of carbon for thousands of years and substantially reducing methane and nitrous oxide emissions from soils.
"The result is that about 50 percent of the biomass carbon is retained," Lehmann said. "By sequestering huge amounts of carbon, this technique constitutes a much longer and significant sink for atmospheric carbon dioxide than most other sequestration options, making it a powerful tool for long-term mitigation of climate change. In fact we have calculated that up to 12 percent of the carbon emissions produced by human activity could be offset annually if slash-and-burn were replaced by slash-and-char."
In addition, many biofuel production methods, such as generating bioenergy from agricultural, fish and forestry waste, produce bio-char as a byproduct. "The global importance of a bio-char sequestration as a byproduct of the conversion of biomass to bio-fuels is difficult to predict but is potentially very large," he added.
Applying the knowledge of terra preta to contemporary soil management also can reduce environmental pollution by decreasing the amount of fertilizer needed, because the bio-char helps retain nitrogen in the soil as well as higher levels of plant-available phosphorus, calcium, sulfur and organic matter. The black soil also does not get depleted, as do other soils, after repeated use.
"In other words, producing and applying bio-char to soil would not only dramatically improve soil and increase crop production, but also could provide a novel approach to establishing a significant, long-term sink for atmospheric carbon dioxide," said Lehmann. He noted that what is being learned from terra preta also can help farmers prevent agricultural runoff, promote sustained fertility and reduce input costs.
a solution in search of a problem...
What's even funnier and made me smile is that this "legend in his own mind" is ignorant of what a bright Jr. High Schooler knows: One can't prove a negative.
[i]How interesting, I remember a decade ago how the enviromentalists stated that the soil in the Amazon jungle was to poor in nutrients for farming crops.[/i]
And if I recall correctly, this was discovered by someone who was trying to study how such an advanced civilization could have ever thrived there prior to Spanish invasion. . .
I think it was some sort of bacteria in the soil, and the ancient civilization knew how to cultivate the bacteria. One truckful they said, could be spread around an acre, and with a few years the entire acre would be the new type of bacterially infested soil.
Then they did the yield tests, and the bacteria treated (but otherwise poor) rainforest soil out-performed all the other modern fertilizers.
There is a good chance this ancient technology will have a profound impact on future economics!
I have read many accounts of early Spanish explorations and can't recall anything this silly, particularly from published versions in the original Spanish journals and diaries.
It's hard to imagine the likelihood of a group focused on reaching the coast for help stopping to make a census involving several million people even assuming such a thing were practicable.
Most likely this historical invention will be repeated over and over until its nonsensical presmise is assumed to be genuine. The artful interpretation of someone not versed in the practicalities of a large scale census in a wild jungle setting.
You obviously do not understand what you tag line means with your ecoliberal lets regulate it attitude. Tell me why it won't work or I do it eh. Moonman!
Now there's a historically significant trick: kill millions of gentle savages from diseases inadvertently introduced by those nasty European white guys but not as living persons who ever had contact with them. They must have used either dead guys or the post office... but I repeat myself...
SO they are going to tear out the jungle for it's dirt. LOL!! Not that is poetic justice.
The best indicator that whatever number existed were savages is the simple knowledge that they are almost entirely gone.
So you've been to Brazil and northern Bolivia, spent years there, and also read all of this guy's scientific papers, right?
Um, I think that he meant "no person still living today ever had contact with them." Whether or not the claim is true (about the millions of people in that civilization), anyone who had contact with them is dead now. :)
The program was based on a detailed journal kept by one of the leaders of the expedition to the coast. They stopped among the towns because they needed food and boat repairs. The shores were extensively settled for many miles according to his reports. He kept a very detailed account because he was afraid he would get into trouble for not going back with food and supplies to help Pizarro (against the Amazon's current). He was also trying to make a complete report for the king's information. Extensive reports of this type were common in that era.
I have also read original reports in Spanish of the early explorers/conquerors. "Cortez' Five Letters to King Carlos" of Spain was one. This was an official report like the one prepared by the Spaniard traveling down the Amazon. The diary of Bernal Diaz, one of Cortez' lieutenants was another. Both books were the length of a modern novel. They were very detailed and agreed on most points. I deliberately read them concurrently to check that aspect. They size and complexity of Mexican civilizations was extremely impressive in their reports.
Wait. They all disappeared due to the white man diseases; all the millions of them with no remnants or traces of libraries to explain how it was all possible. How convenient.
The best indicator that whatever number existed were savages is the simple knowledge that they are almost entirely gone.
This is the most ignorant crap I have ever seen posted on Free Republic. It's one thing to be mistaken, it's quite another to be intentionally stupid and uninformed. You are not merely intentionally ignorant and uninformed, you are PROUD of it!
My advice to you sir, is read a book. Hell, go for broke, read TWO! And not zombie trash like "The Flat Earth" or "The Hollow Earth".
Why not start with "1491"?
Planting their orchards, the first Amazonians transformed large swaths of the river basin into something more pleasing to human beings. In a widely cited article from 1989, William Balée, the Tulane anthropologist, cautiously estimated that about 12 percent of the nonflooded Amazon forest was of anthropogenic origindirectly or indirectly created by human beings. In some circles this is now seen as a conservative position. "I basically think it's all human-created," Clement told me in Brazil. He argues that Indians changed the assortment and density of species throughout the region. So does Clark Erickson, the University of Pennsylvania archaeologist, who told me in Bolivia that the lowland tropical forests of South America are among the finest works of art on the planet. "Some of my colleagues would say that's pretty radical," he said, smiling mischievously. According to Peter Stahl, an anthropologist at the State University of New York at Binghamton, "lots" of botanists believe that "what the eco-imagery would like to picture as a pristine, untouched Urwelt [primeval world] in fact has been managed by people for millennia." The phrase "built environment," Erickson says, "applies to most, if not all, Neotropical landscapes."
"Landscape" in this case is meant exactlyAmazonian Indians literally created the ground beneath their feet. According to William I. Woods, a soil geographer at Southern Illinois University, ecologists' claims about terrible Amazonian land were based on very little data. In the late 1990s Woods and others began careful measurements in the lower Amazon. They indeed found lots of inhospitable terrain. But they also discovered swaths of terra pretarich, fertile "black earth" that anthropologists increasingly believe was created by human beings.
Terra preta, Woods guesses, covers at least 10 percent of Amazonia, an area the size of France. It has amazing properties, he says. Tropical rain doesn't leach nutrients from terra preta fields; instead the soil, so to speak, fights back. Not far from Painted Rock Cave is a 300-acre area with a two-foot layer of terra preta quarried by locals for potting soil. The bottom third of the layer is never removed, workers there explain, because over time it will re-create the original soil layer in its initial thickness. The reason, scientists suspect, is that terra preta is generated by a special suite of microorganisms that resists depletion. "Apparently," Woods and the Wisconsin geographer Joseph M. McCann argued in a presentation last summer, "at some threshold level ... dark earth attains the capacity to perpetuateeven regenerate itselfthus behaving more like a living 'super'-organism than an inert material."
In as yet unpublished research the archaeologists Eduardo Neves, of the University of São Paulo; Michael Heckenberger, of the University of Florida; and their colleagues examined terra preta in the upper Xingu, a huge southern tributary of the Amazon. Not all Xingu cultures left behind this living earth, they discovered. But the ones that did generated it rapidlysuggesting to Woods that terra preta was created deliberately. In a process reminiscent of dropping microorganism-rich starter into plain dough to create sourdough bread, Amazonian peoples, he believes, inoculated bad soil with a transforming bacterial charge. Not every group of Indians there did this, but quite a few did, and over an extended period of time.
When Woods told me this, I was so amazed that I almost dropped the phone. I ceased to be articulate for a moment and said things like "wow" and "gosh." Woods chuckled at my reaction, probably because he understood what was passing through my mind. Faced with an ecological problem, I was thinking, the Indians fixed it. They were in the process of terraforming the Amazon when Columbus showed up and ruined everything.
Scientists should study the microorganisms in terra preta, Woods told me, to find out how they work. If that could be learned, maybe some version of Amazonian dark earth could be used to improve the vast expanses of bad soil that cripple agriculture in Africaa final gift from the people who brought us tomatoes, corn, and the immense grasslands of the Great Plains.
We have a winner!
Sounds like a possible answer to all that "wildfire-causing" undergrowth in western forests.
But for the microbes to do their job, the soil has to be conditioned with charred material first. Once that happens, some of the soil can be mined, and if enough is left it will regenerate.
It remains to be seen whether this technique would produce better yields than modern agriculture. It may be more economical, especially in poorer regions. I wouldn't be surprised either that a sample of the microbes in the Amazonian soil would be needed to "seed" any North American fields that use this technique.
Nowhere do I advocate more regulation, though some amount of regulation is desirable. My tagline is from Reagan, and he too had to remind people that he was neither Libertarian or Anarchist, and that some amount of government is a good thing. He was also a proponent of technological advancement, and experimenting with new ideas.
I do advocate researching this soil technique and experimenting with it. Dismissing it out of hand with puerile comments does nothing to advance Conservatism.
Do you have any sources for purchase of a non sterile sample of this soil?
Thanks for the book excerpt. If it was published in 2002, I take it that they've only recently discovered how this soil was created. I would like to see what would happen if this soil technique was combined with modern agricultural technology.