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dc.contributor.advisorMaxson, C. J.
dc.creatorTakami, Shinichi
dc.description.abstractThe primary objective of this research was to evaluate the physical and physiological feasibility of COâ‚‚ enrichment in field crops. Specific objectives were 1) to find a method of predicting the COâ‚‚ distribution from an area source at ground level in a crop, and 2) to predict the crop carbon dioxide assimilation rate and water use when COâ‚‚ is released. A model of the COâ‚‚ distribution (DIFFUSION) was developed. The model was based on the two-dimensional steady state diffusion equation combined with wind and eddy diffusivity profiles above and within the crop canopy. The model was used to compute the COâ‚‚ concentration at a given space grid point as a function of wind speed in the surface boundary layer, ambient COâ‚‚ concentration, COâ‚‚ release rate and the aerodynamic canopy parameters (canopy height, zero-plane displacement, roughness length, and an exponential coefficient of within-canopy wind profile). The model was tested by an area source COâ‚‚ diffusion experiment in a cotton canopy. The measurements showed that the model effectively predicted the COâ‚‚ profile for a dense and homogeneous canopy under neutral conditions. The DIFFUSION model was combined with CANOPY-LAM-II, a steady state one-dimensional model of mass and energy exchange by a crop canopy, based on the Duncan-Stewart radiation model and a leaf action model. The CANOPY-LAM-II-DIFFUSION model calculated the crop carbon dioxide assimilation rate and water use as a function of the environmental conditions (wind speed, air temperature and dew point above the canopy, COâ‚‚ concentration in the non-release area, global irradiance, and the effective soil water potential), the COâ‚‚ release rate, and the aerodynamic, optical and physiological characteristics of the canopy. ...en
dc.format.extent129 leaves : illustrationsen
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en
dc.subject.classification1974 Dissertation T136
dc.titleThe distribution of carbon dioxide released from a ground level area source in a field crop and its predicted influence on crop assimilationen
dc.typeThesisen A&M Universityen of Philosophyen
dc.format.digitalOriginreformatted digitalen
dc.publisher.digitalTexas A&M University. Libraries

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