Featured Research

from universities, journals, and other organizations

Amazonian Terra Preta Can Transform Poor Soil Into Fertile

Date:
March 1, 2006
Source:
Cornell University
Summary:
Some of the globe's richest soil -- known as terra preta, or Amazonian dark earths -- can transform poor soil into highly fertile ground. Because terra preta is loaded with so-called bio-char -- similar to charcoal -- it also can pull substantial amounts of carbon out of the increasing levels of carbon dioxide in the Earth's atmosphere, helping to prevent global warming.

Cornell researchers applied charcoal to a field on Game Farm Road to study the soil's properties.
Credit: Image courtesy of Cornell University

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.


Story Source:

The above story is based on materials provided by Cornell University. Note: Materials may be edited for content and length.


Cite This Page:

Cornell University. "Amazonian Terra Preta Can Transform Poor Soil Into Fertile." ScienceDaily. ScienceDaily, 1 March 2006. <www.sciencedaily.com/releases/2006/03/060301090431.htm>.
Cornell University. (2006, March 1). Amazonian Terra Preta Can Transform Poor Soil Into Fertile. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2006/03/060301090431.htm
Cornell University. "Amazonian Terra Preta Can Transform Poor Soil Into Fertile." ScienceDaily. www.sciencedaily.com/releases/2006/03/060301090431.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins