ScienceDaily (Nov. 20, 2009) — Sustainable farming, initially adopted to preserve soil quality for future generations, may also play a role in maintaining a healthy climate, according to researchers at the Department of Energy's Oak Ridge and Los Alamos national laboratories.

ORNL’s Madhavi Martin is studying how land-use practices impact soil carbon. (Credit: Image courtesy of DOE/Oak Ridge National Laboratory)

ORNL and LANL scientists are exploring the large potential of the earth's soils to sequester carbon, with estimates claiming that new land-use practices could greatly reduce U.S. carbon emissions by as much as 25 percent. But exactly which practices are the most effective is still unclear, and a research paper published in the Soil Science Society of America Journal shines some light on this topic by introducing an easy-to-use field-portable approach to measure the carbon content of soils.

"This is a tool one could use to measure changes in soil carbon over time and try to establish whether soil carbon stocks are increasing or decreasing as a result of land-use practices," said lead author Madhavi Martin of ORNL's Environmental Sciences Division. "Although it is possible to measure these properties in the laboratory, the simplicity and portability of the device allow researchers exponentially greater flexibility to conduct their investigations."

The paper describes the adaptation of Laser Induced Breakdown Spectroscopy, or LIBS, a technique that once made Martin something of a celebrity when she used it confirm the common origin of two separate pieces of firewood — evidence that eventually led to a confession in a 2006 Texas murder case. LIBS works by measuring the light emitted when a small portion of the sample is annihilated with a laser pulse, a flash that provides an elemental fingerprint of virtually any substance under examination.

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