Simulating Wheat Yield under Changing Temperature Carbon Dioxide and Solar Radiation Levels in Bangladesh
The wheat crop in the tropical region will be most sufferers because of increased temperature in future. Calibrated and validated DSSAT (CERES-Wheat) model was used to evaluate the impact of increased temperatures (1-3oC), elevated CO2 (450 and 550 ppm) levels and radiation changes (5% and 10% increase and decrease) on the yield of wheat in Bangladesh. The highest grain yield of 5194 kg ha-1 was obtained from BARI Gom-28 followed by BARI Gom-27 (4866 kg ha-1) and BARI Gom-26 (4573 kg ha-1) under existing temperature conditions. Wheat yield at Gazipur increased with elevated atmospheric CO2 concentration but decreased with the increase in temperature. On an average, 11.95, 18.97 and 22.82 percent yield reductions were observed with 1, 2 and 3-degree rise in temperatures, respectively under ambient CO2 level at Gazipur. About 2-4% yield compensations are likely if the CO2 level is increased up to 550 ppm. In Dinajpur area, grain yield of wheat (BARI Gom-28) also reduced by about 6-25% depending on temperature rise. BARI Gom-28 gave the highest grain yield (5006 kg ha-1) with 10% increase in solar radiation but, grain yield decreased and the yield was 4182 kg ha-1 with the reduction of solar radiation by 10%. About 4.43% and 7.70% yield increase was predicted if solar radiation increases by 5 and 10%, respectively compared to no radiation changes; whereas 4.94% and 10.02% yield reductions was simulated with 5 and 10% decrease in solar radiation, respectively. Reduction in solar radiation and rise in temperature would reduce wheat yield in Bangladesh, although increased atmospheric CO2 levels might reduce the yield reduction rates.
