Understanding the Role of Microbes in Greenhouse Gas Production in Agricultural Soils
It is critical to understand the role of agricultural practices on soil greenhouse gas (GHG) emissions as expanded collections of agricultural residues are considered for bioenergy production and shifts are made to farming dedicated bioenergy crops. Production and consumption of carbon dioxide, methane, and other GHGs are predominantly mediated by soil microbes, yet the relationship between functional processes and microbial diversity in these systems is poorly understood. Researchers at the DOE Great Lakes Bioenergy Research Center (GLBRC) have examined agricultural GHG production, linking these processes to microbial community activities. The study included agricultural soils under various management practices, both successional grasslands on abandoned agricultural land and mature forests or grasslands that had never been farmed. GHG production and consumption rates were correlated to soil microbial community composition. Rates of methane consumption were found to be highest in non-agricultural forests and grasslands, which also showed the greatest diversity of methane-consuming microbes (i.e., methanotrophs). Successional sites were intermediate in terms of both methane consumption and methanotroph diversity, suggesting a gradual recovery process following disruption by traditional tillage agriculture. These results have important implications in considering sustainable establishment and long-term management of bioenergy landscapes and predictive modeling of GHG emissions.
Levine, U. Y., T. K. Teal, G. P. Robertson, and T. M. Schmidt. 2011. “Agriculture’s Impact on Microbial Diversity and Associated Fluxes of Carbon Dioxide and Methane,” The ISME Journal, DOI:10.1038/ismej.2011.40.