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.
Yea, we are saved!!! I won't kill myself now....
I thought this was a thread about Ray Nagin. ;-D
more hyperbole built on an idea.
I think that world peace can be spread with pre-marital male promiscuity!!!
But I'm not getting published.
Heck, concrete pulls CO2...
So we are going to be saved by a farming technique used by savages thousands of years ago. Wonderful. And all of our energy needs will be met by cold fusion, and that perpetual motion machine invented by that guy in the 1700s will finally be figured out and save us, too.
Did this article just advocate burning down rain forests?
After seeing the replies on this thread I'm wondering who the savages really are. I don't know for sure whether CO2 is causing global warming, but my guess so far is that it is not. However, CO2 is increasing year after year. That's a fact. If this technique works it could have a very positive impact on agricultural productivity as well as lowering CO2 atmospheric concentration, whether that matters or not. This or any other technological adaptation certainly beats giving into the anti-capitalists and signing something stupid like Kyoto.
If you have some knowledge on why this technique won't work, please share your knowledge instead of joining the peanut gallery and making a smartass comment.
Oh, but I love making smartass comments. Go do some slash and crash or whatever it is and show us the way to salvation.
No, but slash and burn is already happening, so why not do it a better way?
Sure, but if it works so well.... Why stop with what is normally slash and burned! ;-)
Who needs rain forest anyway?
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.
It is very poor in its natural state, but these patches of black earth are man made and thousands of years old.
In the next few years the countries near the rainforests are going to become agricultural powerhouses by using already existing agricultural technology from the United States. They have growing seasons that last all year.
I think it advocates charring the rainforest into wholesome black dirt. Apparently this is completely different from burning it into evil black cinders. Gee, I thought everybody knew this... /sarcasm
Some useful comments on slash and char.
There was a very interesting story on public television a few months ago. It seems that when Pizarro and his men invaded Peru in the 1500's, he ran into some trouble and sent a group of men down the Amazon in boats to try to get some help from the Atlantic coast. One of the officers of this expedition wrote in great detail about this very difficult trip.
The thing that amazed me was that there were very large quantities of people living rather well along the shore. I could be wrong, but I think the figure several million was mentioned in the program. Apparently, Pizarro's men were treated well by some of these people. Then of course the Old World gave the New World the gift of Measles and Smallpox and all these towns and cities disappeared. Now in the jungles of the Amazon, the only natives are small very hidden primative tribes. Probably they survived because of their isolation.
In all fairness I should mention that the New World gave the Old World the gift of Syphilis (known in those days as the Pox), but I still think the Americans got the worst end of the deal. At any rate these soils are probably a remnant of what was once a very successful civilization.
I'm very interested in how you know that these people were savages, since no living person has ever had any contact with these peoples. They died out from diseases indavertantly brought to the New World by explorers. They died of these diseases spreading through the indigenous populations without these remote peoples ever knowing where the diseases came from or how to deal with them.
What we do know is that they maintained populations of millions in areas that are now near wilderness. There isn't any reason to think that they were savages, as they were settled agricultural peoples who built massive earthen causeways and raised hillocks for settlement - often nearly a mile across. They lived in villages and towns with populations numbering well into the thousands. They terraformed the Amazon basin, leaving their man-made fertile soils for us to marvel over. They are the exact opposite of the "noble savage" leftists like to fantacize over.
Among all the evidence available to us, I'm not aware of a single element that would lead me to call these ancient peoples savages.
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