Raj, A., Chakrabarti, B.,
Pathak, H., Singh, S.D.,
Mina, U. and
Purakayastha, T.J.
2019
"Growth, yield
and nitrogen uptake
in rice crop grown under
elevated carbon dioxide
and different doses
of nitrogen fertilizer."
Indian Journal of Experimental Biology
57: 181-187.
SUMMARY:
Raj et al. (2019) set out to study
the interaction between
elevated CO2 and nitrogen supply.
Both elevated CO2 and increased
nitrogen supply had a positive impact
on various rice growth-related
parameters, including plant height,
number of tillers, panicle length,
number of panicles, number of
grains per panicle, root biomass,
aboveground biomass and grain yield.
DETAILS:
The six Indian researchers
grew rice in pots
(Oryza sativa, cv. Pusa 44)
in a free-air CO2
enrichment (FACE) facility
at the Indian Agricultural
Research Institute
in New Delhi, India
under ambient (395 ppm)
or elevated (550 ppm)
CO2 and four levels
of nitrogen supply:
-- No nitrogen,
-- 0.6 g pot-1,
-- 0.8 g pot-1 or
-- 1.0 g pot-1,
of which the latter 3 levels
of nitrogen supply
corresponded to
75%, 100% and 125%
of the recommended dose,
respectively.
With respect to grain yield,
this key parameter increased by
+16.9%, +17.6%, +25.5% and +26.1%
under elevated CO2 in the
0, 0.6, 0.8 and 1.0 g pot-1
nitrogen treatments,
respectively.
Raj et al. also report that the
grain and straw nitrogen
concentration decreased
under elevated CO2,
although the nitrogen
content and nitrogen
use efficiency increased.
However, the reduced nitrogen
concentration under elevated CO2
diminished as the nitrogen supply
increased, leading the authors
to conclude that in order
“to maintain plant nitrogen concentration,
[the] application of [an] additional dose
of nitrogen is required.”
