EGU21-9892, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Response of crop evapotranspiration on the elevated CO2 in Northwest China

Dehai Liao1,2 and Jun Niu1,2
Dehai Liao and Jun Niu
  • 1Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China (
  • 2Wuwei Experimental Station for Efficient Water Use in Agriculture, Ministry of Agriculture and Rural Affairs, Wuwei 733000, China

The increase in atmospheric carbon dioxide (CO2) concentration is changing plant physiology, thus affecting terrestrial hydrological response. A nonlinear stomatal conductance response to carbon dioxide concentration (gs – CO2) was incorporated in the VIC model for better representation of the evapotranspiration (ET) response to the elevated CO2. The annual ET of maize and wheat over the agricultural land in Northwest China was found to decrease by 0.54% and 0.21% during 1980–2010, respectively. Under doubled CO2 concentration (660 ppm), the ET reduction of maize and wheat was 23.3 mm and 8.9 mm, which accounted for 4.3% and 1.8% of the corresponding annual ET. The annual ET reduction of maize, under the four future scenarios (RCP4.5_2040s, RCP4.5_2080s, RCP8.5_2040s, and RCP8.5_2080s), was about 1.1–6.4%, resulted from an ensemble mean of eight general circulation models. The effects of elevated CO2 offset part of ET increase caused by the precipitation and temperature changes. This study has practical implications for precise irrigation. The ET response of maize should be paid more attention for its larger potential in saving irrigation water for the studied region. The elevated CO2 concentration will be beneficial for saving irrigation water to a certain degree.

How to cite: Liao, D. and Niu, J.: Response of crop evapotranspiration on the elevated CO2 in Northwest China, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9892,, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.