Research on Soil Chamber Pressure Published in Journal of Geophysical Research

July 25, 2006

LINCOLN, NEBRASKA - LI-COR Senior Application Scientist Liukang Xu, Ph.D., led a group of LI-COR scientists and engineers in a research effort to examine pressure effects on chamber-based soil CO2 flux measurements.  The results of this study were recently published in the Journal of Geophysical Research (JGR), an American Geophysical Union publication.

Findings of the research show that pressure equilibrium between the inside of a soil CO2 flux chamber and the surrounding air outside the chamber must be maintained during a measurement if measured soil CO2 flux is to accurately represent the rate occurring naturally outside the chamber.  Many existing chamber designs employ a simple vent tube, which is effective in calm conditions, but can cause negative pressure excursions during windy conditions.  This negative pressure condition causes an overestimation of soil CO2 flux rates.  A new LI-COR vent design was examined and was found to virtually eliminate negative chamber pressures as a result of windy conditions.  Field data was presented which verified this conclusion. 

To view the abstract for the JGR article, click here.  The full article may be viewed by JGR subscribers; non-subscribers may purchase the article for a fee.  For more information on the LI-8100 Automated Soil CO2 Flux System and the new pressure vent design, including other research posters, click here or call a LI-COR representative at 800-447-3576 or (1) 402-467-3576.

LI‑COR Biosciences is a leader in the design, manufacture, and marketing of integrated instrument systems for plant biology, environmental research, biotechnology, and drug discovery.  LI‑COR instruments for photosynthesis, gas analysis and light measurement are recognized worldwide for standard-setting innovation in plant science research and environmental monitoring.  Founded in 1971, the privately held company is based in Lincoln, Nebraska with subsidiaries in Germany and the United Kingdom.   LI‑COR systems are used in over 100 countries and are supported by a global network of offices and distributors.  Further information can be obtained at

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