基于ORYZA2000模型的北京地区旱稻适宜播种期分析

确定适宜播种期是制定合理的作物栽培管理方案的关键内容之一。在作物模型ORYZA2000有效性验证的基础上，以北京地区为例，利用该模型结合长期历史气候资料，对确定旱稻适宜播种期做了初步研究。结果表明：在不考虑水分因子条件下，北京地区旱稻297安全播期的范围较广，多年平均为3月26日-6月4日；受温度升高的影响，最早播期有提前趋势，而最晚播种期有延后趋势。在同一年份内，播期不同旱稻的产量也有一定的变化，呈现为先升高而后降低的趋势。播期过早或过晚导致生育期平均温度偏低是影响穗干物质累积且造成减产的主要原因，在适宜的播期范围内才能获得高产。以90%-100%当年最高产量潜力作为适宜播期的产量指标，确定北京地区旱稻297的适宜播期变化在5月11日-5月19日之间，相应的产量变化在6689-7257 kg/hm2范围内。研究方法可为其他地区旱稻的播期研究提供借鉴。

Determining suitable sowing dates for aerobic rice in Beijing area using the ORYZA2000 model

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.