Article,
Influence of Rising Atmospheric CO2 and Phosphorus Nutrition on the Grain Yield and Quality of Rice
Cereal Chemistry, 73 (2): 239--243 (1996)
Abstract
Raising the atmospheric CO2 concentration from 350 pulo f CO2 per
liter to a level expected by the end of the next century (700 il/L) influenced
both the grain yield and quality of the short-duration rice (Oryza
sativa) cultivar, Jarrah. Yield was enhanced by up to 58\%, primarily due
to an increase in grain number, although grain size was also greater at
high CO2. Varying the supply of phosphorus influenced the magnitude
of the CO2 response with greatest responses occurring at medium rather
than luxury or low phosphorus supplies. However, yield enhancement by
high CO2 was observed even when phosphorus supply was severely
growth limiting. Chemical (amylose and nutrient concentration) and
physical (relative paste viscosity) measurements made on the ground
grain indicated that cooked rice grain from plants grown under high
levels of CO2 would be firmer. The nutritive value of grain was also
changed at high CO2 due to a reduction in grain nitrogen and, therefore,
protein concentration. However, total nitrogen content per grain was
unaffected by high CO2. In contrast, phosphorus content per grain was
greater at high CO2 and there was a strong correlation between magnesium
and phosphorus concentrations. These results indicate that there is
a need to plan for the inevitable rise in atmospheric CO2 concentrations
by selecting genotypes that will maintain suitable quality characteristics
under global change
