Palacios, C.J., Grandis, A.,
Carvalho, V.J., Salatino, A.
and Buckeridge, M.S.
2019
Isolated and
combined effects
of elevated CO2 and
high temperature on the
whole-plant biomass and
the chemical composition
of soybean seeds.
Food Chemistry 275: 610-617.
NOTE:
Palacios et al. (2019) say
"literature containing
evidence of combined
effects of both
elevated CO2 and
high temperature
on the yield
evidence of combined
effects of both
elevated CO2 and
high temperature
on the yield
and composition
of grains over
the development
and grain filling
is scarce."
They studied the impact
of elevated CO2 and high
temperature on a key
soybean variety
(cv. MG/BR Conquista)
grown throughout
Brazil.
SUMMARY:
Positive effects of
rising atmospheric CO2
will more than compensate
for any potential negative
growth effects from a
modest temperature rise.
Relative to ambient CO2
and ambient temperature
conditions, elevated CO2
alone had a positive impact
on soybean grain number
(41% increase) and
grain biomass (28% increase)
whereas elevated temperature
had a negative impact.
In combination,
however,
the positive
yield-enhancing
effects of elevated CO2
cancelled out the yield
retarding effects of
elevated temperature
such that there was no
significant difference
in soybean grain number
or biomass between the
Elev and Elev/Temp
treatments.
DETAILS:
Conducted in open-top
chambers at the LAFIECO
laboratory of the
Botany Department,
University of São Paulo.
Soybean seedlings
were sown in pots in
the open-top chambers
and grown under either
ambient (380 ppm)
or elevated (800 ppm)
CO2 concentrations
and ambient or
elevated (+4°C)
temperatures
throughout
the course of
the growing season.
The four resultant
treatments included:
ambient CO2 and
ambient temperature
(Amb),
elevated CO2 and
ambient temperature
(Elev),
ambient CO2 and
elevated temperature
(Amb/Temp)
elevated CO2 and
elevated temperature
(Elev/Temp).
Chart Below:
Values followed
by the same letter
are not significantly
different (p < 0.05).
Percentages shown in red
indicate the percent change
in grain number or biomass
due to elevated CO2
under either ambient
or elevated temperature
conditions.
