Soybean Canopy Growth, Photosynthesis, and Transpiration Responses to Whole‐Season Carbon Dioxide Enrichment 1

作者：Pierce H. Jones, L. H. Allen, James W. Jones, Kenneth Jay Boote, W. Joseph Campbell · 发表于：Agronomy Journal · 年份：1984 · DOI：10.2134/agronj1984.00021962007600040030x · 被引用次数：117 · 研究领域：Plant responses to elevated CO2、Climate variability and models、Atmospheric and Environmental Gas Dynamics

Abstract Soybeans [ Glycine max (L.) Merr. cv. Bragg] were grown throughout their life cycle in six controlled‐environment chambers that maintained CO 2 concentrations at 330,450,600, and 800 µmol CO 2 mol −1 air. Air temperatures were controlled, and solar radiation and dewpoint temperatures were measured continually for each chamber. Net photosynthesis and transpiration were computed on 5‐min intervals. The CO 2 enrichment had no apparent effect on the rate of mainstem node development, but leaf area increased at a faster rate proportional to the CO 2 concentration. Daytime CO 2 exchange rate (CER) increased with increasing CO 2 and followed the same trend as final yield. Midday CER was typically about 90 µmol CO 2 m −1 of ground area s −1 for 800 µmol mol −1 and 60 µmol CO 2 m −2 ground area per second for 330 µmol mol −1 chambers. Canopy transpiration rates, leaf area index and vapor pressure deficits were used to compare bulk canopy resistances among CO 2 treatments. Bulk canopy resistance (stomatal and boundary‐layer) of the 800 µmol mol −1 treatment was about 1.6 times that of the 330 µmol mol −1 CO 2 treatment. These results imply that the expected continued increase in global atmospheric CO 2 will increase both agricultural productivity and water use efficiency.