Li, X., Ulfat, A., Shokat, S.,
Liu, S., Zhu, X. and Liu, F.
2019
Responses of carbohydrate
metabolism enzymes in leaf
and spike to CO2 elevation
and nitrogen fertilization
and their relations to
grain yield in wheat.
Environmental and
Experimental Botany
164: 149-156.
NOTE:
Wheat is one of the
most studied crops
in CO2 enrichment
studies.
The six researchers
investigated the
interactive effect
of CO2 and nitrogen
fertilization on the
cultivar Lianmai6.
SUMMARY:
Elevated CO2
had a significant,
positive effect on
photosynthesis
and growth,
no significant
impact was noted
for nitrogen supply
treatment, nor was
there any significant
interaction between
CO2 level and
nitrogen supply.
Elevated CO2 stimulated
both net photosynthesis,
(An) and grain yield.
In the N1 treatment
these parameters
increased by
+12.3%
and +10.0%,
respectively,
whereas in the
N2 treatment
they rose by
+21.4%
and +11.4%,
respectively.
DETAILS:
The wheat plants
were grown in a
climate-controlled
greenhouse
to maturity
at the University
of Copenhagen,
Tåstrup, Denmark
from December 2016
to April 2017.
Ntrogen fertilization
was applied
as normal
(N1 treatment;
1 g N applied
as NH4NO3)
or twice-normal
(N2 treatment;
2 g N applied
as NH4NO3)
and atmospheric
CO2 concentrations
were ambient (400 ppm)
or twice-ambient (800 ppm).
Chart Below:
Net photosynthesis
(An, Panel A)
and grain yield
( Panel B)
of wheat growing
under ambient
(400 ppm)
or elevated CO2
(800 ppm)
at two different
nitrogen fertilizer
rates (N1 and N2
for normal and
twice-normal
application rates,
respectively).
Mean values
± SE are shown.
The red text
indicates the
percentage
enhancement
in net photosynthesis
and grain yield due to
elevated CO2 at a
given nitrogen
treatment level.
