|Rogers Jr, Hugo|
|Pritchard, Seth - AUBURN UNIVERSITY|
|Davis, Micheal - UNIV. SOUTHERN MISS.|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 12, 2003
Publication Date: May 12, 2003
Citation: Rogers, H.H., Prior S.A., Runion, G.B., Torbert, H.A.,and, Pritchard, S.G., Davis, M.A. 2003. Global change and belowground processes in agricultural systems. National Science Foundation, North American Carbon Program Joint PI Meeting (NACP '03). Arlington, Arlington, VA May 12-14. Technical Abstract: The fuel concentration of CO2 in the atmosphere is increasing at an unprecedented rate, due primarily to fossil burning and land use change. Aside from the debate on predicted shifts in the Earth's climate, plants are directly affected by increased CO2, the essential substrate of photosynthesis, which in turn impacts delivery of carbon to the soil. Plant growth, soil carbon dynamics, microbial activity, and groundwater quality are inextricably linked. Therefore, we are looking at them simultaneously in an integrated fashion within a single experiment. Carbon flux to plants and soil is being determined along with supporting data on soil physicochemical properties and crop growth. Determinations of plant growth, physiology, and yield within conventional and conservation cropping systems will address our goal to reduce uncertainty regarding the effects of rising atmospheric CO2 on crop production and food security. To address our second primary goal (to reduce uncertainty regarding the role of agronomic ecosystems in the sequestration of atmospheric CO2), emphasis in these research efforts will be given to measuring soil carbon storage, root development patterns, and to characterizing the rhizosphere. The relationships of N to C dynamics and to water quality will be examined. In addition to aboveground biomass, root growth, decomposition, and microbial community structure will be quantified with respect to C flow. The specific objectives of this research include: determine the response of above- and belowground plant growth to elevated atmospheric CO2 within a conventional vs. a conservation cropping system; determine if plants grown in elevated CO2 have altered tissue chemistry; determine the effects of atmospheric CO2 concentration and tillage on changes in the structure and activity of soil microbial communities, including beneficial microorganisms such as mycorrhizal fungi; determine the effects of elevated CO2 on plant tissue decomposition; and determine the effects of differing cropping systems (conventional vs. conservation) under ambient and elevated CO2 on soil chemical and physical properties, with emphasis on soil carbon and nitrogen dynamics and storage. Integrating data from these objectives will provide a more thorough, mechanistic understanding of the potential which differing agronomic systems have in mitigating global change via sequestration of atmospheric carbon dioxide.