Soil that was once thought to be the least vulnerable to decomposition is actually the most sensitive to increasing temperatures, making it more likely to release carbon into the atmosphere as the climate warms, according to researchers at Kansas State University and a colleague in Colorado.
Joseph Craine, K-State research assistant professor of biology; Kendra McLauchlan, K-State assistant professor of geography; and Noah Fierer, assistant professor of ecology at the University of Colorado at Boulder, are the authors of "Widespread Coupling between the Rate and Temperature Sensitivity of Organic Matter Decay," published recently in the journal Nature Geoscience. Their data will be used to develop a model for more accurately predicting future global warming.
With more than $450,000 in grants from the National Science Foundation, the three researchers analyzed microbial decomposition of soil organic matter from 28 different sets of soils collected from sites across North America.
Based on their research and the results from other studies that incubated a range of organic materials like simple sugars, leaves, roots and other soils, the group discovered a general relationship that clearly shows that carbon molecules in the soil with the most chemical resistance to microbial enzymes are most sensitive to temperature increases.
The study raises concerns that previous science may have vastly underestimated how much carbon will be released into the atmosphere from the soil with warmer temperatures.
More information on this research will be in your January Kansas Farmer magazine.