气候变化背景下广东早稻播期的适应性调整

Adaptation and determination of sowing date under climate change in early matured rice in Guangdong Province

利用广东省86个气象站1961-2009年资料以及2009年早稻地理分期播种试验数据,分析了气候变暖背景下广东早稻生长季的气候变化特点,并探索适应气候变化的广东早稻播种期调整的可行性。结果表明,自1997年以来,广东早稻生长季气候变化较为显著:(1)广东早稻生长季气候变暖明显,热量资源增加显著;光照资源略有减少;降水量略多于常年,但年际变幅加大;(2)春季低温阴雨天气结束日期提前,总日数减少;早稻幼穗分化期低温冷害结束日期提早;"龙舟水"期间降水集中期推后。在考虑气候资源与灾害变化特征的基础上,提出了广东早稻播种期调整方案为南部地区提前7-10d,中部地区提前5-7d,北部地区提前3-4d。广东早稻播期调整的研究,不仅是早稻应对气候变化的需要,而且对全年农业生产布局调整也具有重要意义。

Based on daily climatic data collected from 86 weather stations from 1961 to 2009 in Guangdong Province and field experiments for different sowing date in early matured rice in five locations e.g.Shaoguan,Guangzhou,Zhaoqing,Zhanjiang,Shantou in 2009,the characteristics of climate change during growing season in early matured rice cultivars were analyzed to explore the feasibility of the sowing date under climate change.The results showed that：（1） since 1997,average temperature increased 0 8℃ than that of the contrast（1961-1996）,above 10℃ accumulative temperature increased 139℃.Climate warming effect was accelerated,heat resource significantly improved in growth period of early matured rice in Guangdong province.Sunshine hour during growing season slightly decreased 11 hours than that of the contrast.Total precipitation during growing season slightly increased 60 mm compared to that of the contrast,with increasing variability between years.In early growing season,the relation coefficients（R2） of average temperature,above 10℃ accumulative temperature and sunshine hour were 0.2279,0.241,0.198,respectively,showed a significant difference.The relation coefficient（R2） of total precipitation was 0.0375,showed no significant difference.（2） since 1997,the date of terminating continuous low temperature and rainy period in spring（CLTR） were 12 days earlier than the mean value of the contrast（1961-1996）,total days of CLTR decreased 4 days.It significantly differed between locations.For the date of terminating CLTR,it was 15-20 days earlier in the southern,5 days earlier in middle and the northern.For total days of CLTR,it decreased 4-8 days in the southern region,and 3-5 days in middle and the northern region.Thus,the harm of CLTR was gradually abated in rice seedling.The ending dates of low temperature occurred in the May,which harmed in young panicle differentiation stage of rice,was earlier than the mean value of the contrast（1961-1996）.Its frequency and influence became smaller and smaller in Guangdong.The first day continuous heavy rain period during the last 10 days of May to the first 10 days of June,called ＂Dragon Boat Water＂,occurred after 6 June,it delayed 5 days than the contrast.With respect to the climatic resources,characteristics of meteorological hazards and rice varieties in Guangdong province,we suggested that the sowing date of early matured rice cultivars should be earlier,e.g.7-10 days earlier in the southern region,5-7 days earlier in middle region and 3-4 days earlier in the northern region.This study is not only for the adaptation to climate change but also important for readjusting agricultural farming system.