This award will support collaborative research in physiological ecology between Drs. Ronald D. DeLaune and William H. Patrick, Center for Wetland Resources, Louisiana State University and Dr. O. Van Cleemput, Faculty of Agricultural Sciences, University of Ghent, Belgium. The project addresses the formation and consumption of biogenic gases in soils and seeks to define the conditions under which specific gases are formed, and the rates and conditions leading to their consumption. The development of fully or partly anoxic conditions occurs in both waterlogged and in well drained soil conditions. A combination of high oxygen consumption through the presence of abundant, readily available carbon and limited oxygen supply induced by a high water content is the main reason for the onset of anaerobic conditions. These conditions are responsible not only for stress to plants, but are also favorable for the formation of gaseous hydrocarbons, such as methane, ethylene, ethane, propane and butane. These gases can have adverse effects on plants and can negatively influence the gaseous environment. The aim of this project is to investigate to what extent soils or sediments can be a source for gaseous hydrocarbons. Gaseous hydrocarbon production and evolution will be related to sediment Eh, pH and amendments, including different types of organic material. The investigations will be carried out in the laboratory, as well as in the field. The results of this study are expected to provide a better understanding of the carbon cycle and to lead to added information on the composition of the gaseous environment in soils and sediment, including possible source- sink relationships with the atmosphere. The research will benefit from the combined expertise of the US investigators in nutrient interactions and of the Belgian investigators in gaseous hydrocarbons and anaerobic soils.
