Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 25, 2001
Publication Date: October 25, 2001
Citation: PRUEGER, J.H., HATFIELD, J.L. SEASONAL PATTERNS OF CARBON DIOXIDE FLUX OVER CORN CANOPIES. ASA-CSSA-SSSA ANNUAL MEETING ABSTRACTS. 2001. CD-ROM. MADISON, WI. Technical Abstract: Concern about levels of carbon dioxide and exchange of CO2 over Midwestern cropping systems has prompted a number of questions about the seasonal dynamics of these fluxes. A study was developed to evaluate the CO2 fluxes over corn (Zea mays L.) canopies in different soil types within a production field in central Iowa. Observations of CO2 flux were combined with energy balance and H2O fluxes throughout the season and linked with growth analysis to determine the interactions of growth with gaseous fluxes. We observed that CO2 fluxes were related to H2O vapor fluxes and when the crop was actively growing during the early portion of the growing season the differences between soil types was quite large. These differences were often as large as 50% with the higher soil water availability. Growth analysis showed that these areas of the field were producing less biomass. Observations of leaf N content also showed that N availability affected carbon uptake. Quantifying these interactions provides a better understanding of how we improve soil management practices.