Intensifying drought eliminates the expected benefits of elevated carbon dioxide for soybean.
Stimulation of C3 crop yield by rising concentrations of atmospheric carbon dioxide ([CO2]) is widely expected to counteract crop losses that are due to greater drought this century. But these expectations come from sparse field trials that have been biased towards mesic growth conditions. This eight-year study used precipitation manipulation and year-to-year variation in weather conditions at a unique open-air field facility to show that the stimulation of soybean yield by elevated [CO2] diminished to zero as drought intensified. Contrary to the prevalent expectation in the literature, rising [CO2] did not counteract the effect of strong drought on photosynthesis and yield because elevated [CO2] interacted with drought to modify stomatal function and canopy energy balance. This new insight from field experimentation under hot and dry conditions, which will become increasingly prevalent in the coming decades, highlights the likelihood of negative impacts from interacting global change factors on a key global commodity crop in its primary region of production.
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Sharon B
SB
Gray
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Orla
O
Dermody
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Stephanie P
SP
Klein
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Anna M
AM
Locke
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Justin M
JM
McGrath
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Rachel E
RE
Paul
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
David M
DM
Rosenthal
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Ursula M
UM
Ruiz-Vera
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Matthew H
MH
Siebers
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Reid
R
Strellner
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.|United States Department of Agriculture, Agricultural Research Service, Urbana, Illinois 61801, USA.
Elizabeth A
EA
Ainsworth
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.|United States Department of Agriculture, Agricultural Research Service, Urbana, Illinois 61801, USA.
Carl J
CJ
Bernacchi
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Stephen P
0000-0002-8501-7164
SP
Long
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.|United States Department of Agriculture, Agricultural Research Service, Urbana, Illinois 61801, USA.
Donald R
DR
Ort
Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
Andrew D B
AD
Leakey
D002245:Carbon Dioxide / Q000378:metabolism*; D057231:Climate Change; D055864:Droughts; D013025:Glycine max / Q000502:physiology*; D013312:Stress, Physiological; D014887:Weather
D002245:Carbon Dioxide