Rich soil good for trapping carbon dioxide - study
Date: 09-Sep-02
Country: USA
The protein, glomalin, glues soil particles and organic matter together which stabilizes soil and keeps carbon from escaping into the atmosphere. Farmland and forests around the world are seen as valuable to offset carbon emissions from cars and industrial plants, offering the potential for carbon credit emission trading.
Kristine Nichols, a soil scientist with the USDA's Agricultural Research Service, analyzed glomalin in soils collected from Colorado, Georgia, Maryland and Nebraska. Tests showed that the glomalin stored nearly one-third of the carbon absorbed by soil, an amount far greater than humic acid which had been thought to store the most carbon.
Glomalin gives soil the rich, fertile texture readily recognized by farmers and longtime gardeners. It lasts from 7 to 42 years in soil, depending on conditions, researchers said.
Another USDA researcher, Sara Wright, is studying glomalin levels to measure the amount of carbon stored in soils beneath tropical forests.
"Glomalin is unique among soil components for its strength and stability," Wright said. Other soil components that contain carbon are quickly degraded and break down, she said.
"Our next step is to identify the chemical makeup of each of its parts, including the protein core, the sugar carbohydrates, and the attached iron and other possible ions," she said.
Global warming has been linked to the growing amount of heat-trapping gases such as carbon dioxide in the atmosphere. Scientists say the gradual increase in temperature may melt glaciers, increase sea levels and lead to broad weather changes in crop-growing areas.
