北京农业气候资源变化特征及其对不同种植模式玉米各生育期的影响

分析1960—2008年北京山区和平原的春玉米、平原夏玉米不同生育期的热量、水、光等农业气候资源的变化趋势和突变特征,研究农业气候资源变化对玉米可能产生的影响。利用统计回归分析方法研究不同种植模式玉米在关键生育期内主要农业气候资源历史时间序列特征,同时以突变理论中的Mann-Kendall方法和Pettitt方法分析主要气候资源的趋势变化特征并检测其突变特征;在数据分析的基础上,结合国内和国际相关研究成果讨论北京市气候资源变化对玉米生长的可能性影响并给出相应对策。结果显示:近50 a来北京地区大于10℃的年活动积温和玉米全生育期有效积温呈现明显增长趋势,变化过程中无明显的突变特征;玉米播种—拔节期降水量呈增加的趋势,平原夏玉米在拔节—抽雄期和全生育期、平原春玉米在吐丝—成熟期降水量减少趋势均达显著水平,其它生育期间降水呈现不明显的下降趋势,但无明显突变点;除了抽雄—吐丝期外,玉米各生育期光照资源呈现明显的下降趋势,不同生育期的突变点均出现在20世纪80年代中期到90年代中期。北京地区农业气候资源变化趋势对玉米生产有利有弊:对积温增长的响应应以灌浆期延长为主要方式,对降水减少的响应应以种植抗旱品种和加大抗旱技术研究为主,对光照资源显著减少的对策应以调节田间通风透光和培育耐阴性品种为主。

Agricultural Climate Resources Change Characteristics of Beijing and Related Impacts on Maize Planted in Different Zones and Different Growth Periods

This paper aims to research the potential impacts resulted by the agricultural climate change by analyzing agricultural climate resources of heat, precipitation and sunshine for maize, including mountain spring maize, plain spring maize and plain summer maize, in sowing to elongation growth period, elongation to anthesis growth period, anthesis to silking growth period, silking to mature growth period, and the whole growth period. Statistic regression was used to reveal the time series characteristics of different kinds of maize during key growth period. Besides, we adopted Mann-Kendall and Pettitt methods in classical abrupt change theory to analyze trends and detect abrupt change characteristics of agricultural climate resources. On the basis of data analysis, we discussed the potential impacts on maize resulted from climate change according to relative research of other scholars and proposed corresponding solutions to it. The results are as follows: In recent 50 years, for Beijing, the annual active accumulated temperature and effective accumulated temperature ≥10 ℃ for maize in the whole growth period, showed no significant increasing trend without abrupt change point; while precipitation in sowing to elongation growth period got an increasing trend, precipitation of plain summer maize in elongation to anthesis growth period, plain spring maize in silking to mature growth period, hold a significant descending trend, and the other growth period showed no significant descending trend, with all growth periods having no significant abrupt change points; moreover, except for anthesis to silking growth period, sunshine resources in all the other growth periods showed significant descending trends with significant abrupt change points occurring between the mid 1980s and mid 1990s. And it concluded that according to international relative research on climate change, agricultural climate resources changing trends of Beijing may produce both positive and negative impacts on maize. In response to the increasing trend of accumulated temperature, measures should be taken to prolong grain-filling growth period. As to the descending trends of precipitation, maize variety of drought-resistance and effective drought fighting technique should be introduced; solutions for solving the descending trend of sunshine hours, maize of strong shade tolerance should be selected and attention should be paid to planting at proper intervals in order to improve ventilation and light transmission conditions.