Premium
CO 2 enrichment increases water‐use efficiency in sorghum
Author(s) -
Conley Matthew M.,
Kimball B. A.,
Brooks T. J.,
Pinter P. J.,
Hunsaker D. J.,
Wall G. W.,
Adam N. R.,
LaMorte R. L.,
Matthias A. D.,
Thompson T. L.,
Leavitt S. W.,
Ottman M. J.,
Cousins A. B.,
Triggs J. M.
Publication year - 2001
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.2001.00184.x
Subject(s) - sorghum , chemistry , environmental chemistry , agronomy , environmental science , biology
Summary• Sorghum ( Sorghum bicolor ) was grown for two consecutive seasons at Maricopa, AZ, USA, using the free‐air CO 2 enrichment (FACE) approach to investigate evapotranspiration of this C4 plant at ample and limited water supplies. • Crop evapotranspiration (ET) was measured using two CO 2 concentrations (control, c. 370 µmol mol −1 ; FACE, ambient +200 µmol mol −1 ) and two irrigation treatments (well watered and water‐limited). Volumetric soil water content was measured before and after each irrigation using neutron scattering techniques. • Averaged over both years, elevated CO 2 reduced cumulative ET by 10% when plants were given ample water and by 4% under severe drought stress. Water‐use efficiency based on grain yield (WUE‐G) increased, due to CO 2 enrichment, by 9% and 19% in wet and dry plots, respectively; based on total biomass, water‐use efficiency (WUE‐B) increased by 16% and 17% in wet and dry plots, respectively. • These data suggest that in the future high‐CO 2 environment, water requirements for irrigated sorghum will be lower than at present, while dry‐land productivity will increase, provided global warming is minimal.