Rice photosynthesis and evapotranspiration in subambient, ambient, and superambient carbon dioxide concentrations

Journal Article · · Agronomy Journal; (USA)

DOI:https://doi.org/10.2134/agronj1990.00021962008200040034x· OSTI ID:5852617

Baker, J T; Allen, Jr, L H; Boote, K J; Jones, P; Jones, J W ^[1]

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1. Univ. of Florida, Gainesville (USA)

The current global rise in atmospheric carbon dioxide concentration, (CO{sub 2}), has stimulated interest in the response of agricultural crops to (CO{sub 2}). The objectives were to determine the effects of (CO{sub 2}) on photosynthesis, evapotranspiration, and water use efficiency of rice (Oryza sativa, L., cv. IR-30). Rice plants were grown in naturally sunlit, plant growth chambers in subambient (160 and 250), ambient (330), or superambient (500, 660, and 900 {mu}mol CO{sub 2} mol{sup {minus}1} air) (CO{sub 2}) treatments. Photosynthetic light response curves were analyzed to obtain estimates of canopy light utilization efficiency ({alpha}) and canopy conductance to CO{sub 2} transfer ({tau}). Estimates of {alpha} increased with increasing (CO{sub 2}) treatment with the greatest increase in the 160 to 500 {mu}mol mol{sup {minus}1} treatments. Estimates of {tau} were more variable than those for {alpha} and were not different among (CO{sub 2}) treatments. Photosynthetic rates increased with increasing (CO{sub 2}) treatment from 160 to 500 {mu}mol mol{sup {minus}1} followed by a leveling off of the response among the superambient (CO{sub 2}) treatments. Evapotranspiration decreased while water-use efficiency increased with increasing (CO{sub 2}). Short-term cross-switching of (CO{sub 2}) among the chambers revealed a profound adaptive response to long-term (CO{sub 2}) growth treatments. Photosynthetic rate, measured at a common (CO{sub 2}), decreased with increasing long-term (CO{sub 2}) growth treatment. The lack of further photosynthetic response above the 500 {mu}mol mol{sup {minus}1} (CO{sub 2}) treatment appears to indicate a need to select or screen rice cultivars for increased response to superambient (CO{sub 2}) in order to more fully take advantage of future increases in global atmospheric (CO{sub 2}).

• OSTI ID: 5852617
• Journal Information: Agronomy Journal; (USA), Journal Name: Agronomy Journal; (USA) Vol. 82:4; ISSN 0002-1962; ISSN AGJOA
• Country of Publication: United States
• Language: English

Related Subjects

553000* -- Agriculture & Food Technology
560300 -- Chemicals Metabolism & Toxicology
60 APPLIED LIFE SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL EFFECTS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CEREALS
CHALCOGENIDES
CHEMICAL REACTIONS
GRASS
GROWTH
LILIOPSIDA
MAGNOLIOPHYTA
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANT GROWTH
PLANTS
RICE
SYNTHESIS
TRANSPIRATION