Qiao, Y., Miao, S., Li, Q.,
Jin, J., Luo, X. and Tang, C.
2019.
"Elevated CO2 and temperature
increase grain oil concentration
but their impacts on grain yield differ
between soybean and maize grown
in a temperate region."
Science of the Total Environment 666:
405-413.
SUMMARY:
Lots of good news here !
Elevated temperature
and elevated CO2 together
enhanced the quantity
and quality of soybean
and maize grain yields.
Such findings are
even more evidence
that a warmer planet,
with more CO2 in the air,
will increase food supplies.
DETAILS:
Qiao et al. (2019)
investigated
elevated temperature,
with and without
elevated CO2,
on soybean
(Glycine max, cv. Dongsheng 2)
and maize (corn)
(Zea mays, cv. Demeiya 1)
yield and grain quality.
The six scientists grew
the two crop species
in three environmental
treatments in open-top
chambers located in
Hailun County,
Heilongjiang, China,
across five growing
seasons.
The three treatments:
(1) ambient temperature
and ambient CO2,
(2) ambient CO2 and
elevated temperature
(2.1 °C above ambient),
(3) elevated temperature
(+1.5 °C above ambient)
and elevated CO2 (700 ppm).
Elevated CO2 concentrations
were only during daylight hours
(0600-1800 hours).
Results are summarized
below and in the charts.
Average grain yield of soybeans
increased by +31% in the elevated
temperature and elevated CO2
(eTeCO2) treatment, compared to
the control.
There was no significant difference
between the control and elevated
temperature (eT) only treatment
for soybeans.
For maize, average grain yields
rose by +25% in both
the eT and eTeCO2 treatments
compared to control.
For grain oil concentration,
which Qiao et al. say is
"an important
quality indicator",
it was +9% higher
and +14% higher
in soybeans, and
+12% higher
and +20% higher
in maize in the
eT and eTeCO2
treatments,
respectively.
Grain protein concentration
in both crops were not
statistically different among
the three treatments for
soybean or maize, but did
increase (relative to control)
by +3.3% in both eT and eTeCO2
treatments for soybean,
by +3.5% in the eT treatment
for maize and by +4.6% in the
eTeCO2 treatment for maize.
Qiao et al. also measured
several nutrients in the grains.
Phosphorus (P), potassium (K),
calcium (Ca), iron (Fe), zinc (Zn)
and manganese (Mn) tended to be
somewhat enhanced in the
eTeCO2 treatment.
Relative to the ambient control,
the percent change in P, K, Ca, Fe,
Zn and Mn in the eTeCO2 treatment
was +5%, +2.5%, +2.6%, +8%, +2%
and -10% for soybean, and
+2%, +4%, (-1%), +16%, 0%,
and +8% for maize.
