Abstract
We predict every 10-year potential rice yield in the next 100 years, using results from the transient CO2 experiment of the MRI's CGCM and the rice crop simulation model named SIMRIW. In this study, we chose 'Koshihikari' and 'Kirara 395' as the representative cultivars in Japan. The maximum potential yield under various climatic conditions is considered using the current planting day and also after adoption of an optimal planting day. Using the current planting day, the growth duration is predicted to be 16-19 days shorter, resulting in a 15% decrease in the potential yield of 'Koshihikari' for the next 100 years. On the other hand, after adopting the optimal planting day, the potential yield can maintain the current level or show an increase of 10-15%. The potential yield of 'Kirara 395', cultivated in Sapporo and Asahikawa, which are the northernmost places for planting rice, is predicted to show a 20% increase after adopting the current planting day, and a 25% increase after adoption of the optimal one for the next 100 years. Moreover, it is predicted that it would be possible to harvest 'Koshihikari' even in the northern part of the Tohoku and Hokkaido districts after 30-40 years, and that the potential yield can reach more than 8t ha-1 after 100 years.
