Abstract:The determination of suitable sowing dates is critical for optimizing cropping systems in relation to climatic conditions. In this paper, we use a validated rice growth simulation model, ORYZA2000, along with long-term historical weather data to determine suitable sowing dates for aerobic rice the Beijing area. Simulations are carried out for variety HD297 under potential production situations in which crop growth and development are only determined by solar radiation and temperature, and in which irrigation water and nutrients are in ample supply and the crop is optimally protected from pests and diseases. The optimum sowing date is defined as those dates which obtain 90%-100% of the maximum simulated yield. Results suggest a wide possible sowing range, from March 26 to June 4. Simulated grain yield is low with early sowing, increases with later sowing, and then decreases again with sowing at the end of the sowing window. The low yields with both early and late sowing are caused by low average temperatures experienced during the crop growth period. Increasing temperatures caused by climate change widen the sowing window, both by advancing the earliest sowing time and prolonging the late sowing period. The optimum sowing dates, resulting in highest yields, are between May 11 and May 19, with realize yields potentials of 6689-7257 kg/hm2. The results of this study provide useful information on sowing opportunities for aerobic rice that can be extended to farmers in the North China region.