湘中地区双季稻生长期内气候变化特征

Characteristics of Climate Change During Growth Period of Double Cropping Rice in Central Hunan

为探明湘中地区双季早晚稻生长期内气候变化特征及对生产的影响,以该地区1960—2019年的双季早、晚稻生育期内逐日地面气象观测数据为研究对象,比较分析了近60 a早晚稻生长期内各生育时期的温、光、水等气候资源变化趋势,探讨在区域气候变化的背景下,双季早晚稻生产如何充分利用有利气候变化以及避开不利气候变化。结果表明:早稻生长期内的日平均气温、平均日最高气温、平均日最低气温均呈上升趋势,播种育秧期增幅最大,分别为0.433、0.808和0.428℃/10a;播种育秧期和移栽返青分蘖期的日照时数为增加;降水量的增加主要发生在生长后期。晚稻生长期内日平均气温除孕穗期略有下降外,其余生育时期均呈上升趋势;播种育秧期、抽穗期和灌浆成熟期3个时期平均日最高气温均表现出一定幅度的升高,增幅最大的是灌浆成熟期;平均日最低气温表现为持续上升,增幅最大的为灌浆成熟期,达0.226℃/10a;孕穗期的日照时数降幅最大,下降约11.02 h/10a,其次是移栽返青分蘖期,下降约6.656 h/10a。该区域气候变化对早稻而言是利大于弊,而对晚稻来说则制约了其高产潜力的发挥。因此,湘中地区早晚稻生产可采取早稻适当提前播种并搭配迟熟晚稻品种的技术对策。

To explore the characteristics of climate change during growth period of double cropping rice in central Hunan and its possible impact on rice production,the daily ground meteorological observation data of double cropping early and late rice growth period from 1960 to 2019 in central Hunan were taken as the research object,the change trends of temperature,light,water and other climate resources in each growth period of early and late rice in recent 60 years were compared and analyzed,and under the background of regional climate change,how to make full use of favorable climate change and avoid adverse climate change in double cropping early and late rice production was discussed.The results showed that:the daily average temperature,average daily maximum temperature and average daily minimum temperature all increased during the growth period of early rice,and the largest increase was in the sowing and seedling raising period,which were 0.433℃/10a,0.808℃/10a and 0.428℃/10a,respectively.The increase of sunshine hours mainly occurred in the seeding and seedling-raising stage,and transplanting and tillering stage of early rice;the increase of precipitation mainly occurred in the late growth stage.The daily average temperature during the growth period of late rice showed an upward trend except that it decreased slightly at booting stage;the average daily maximum temperature in the three periods of late rice seeding and seedling-raising stage,heading stage,and filling and ripening stage increased by a certain extent,and the filling and ripening stage increased the most.The average daily minimum temperature in the growth period of late rice increased continuously,and the largest increase was in the filling and ripening stage,reaching 0.226℃/10a.The largest decrease of sunshine hours in late rice was at booting stage,reaching-11.02h/10a,followed by the transplanting and tillering stage,which was-6.656h/10a.The regional climate change would be beneficial to early rice production,but had a negative effect on the yield potential of late rice.Therefore,the early and late rice production in central Hunan can take the technical countermeasures of timely and early sowing of early rice and matching with late maturing late rice varieties.