近50年四川省水稻生产潜力变化特征分析

气候变化对农业生产的影响日益加剧,特别是作为我国粮食重要产区的四川。科学评价气候变化对四川省水稻生产的影响对于区域农业可持续发展具有重要意义。本文基于四川省45个气象站点50年的气象数据和20年的水稻生育期资料,采用侯光良法分析了四川省7个水稻种植区的水稻光合生产潜力、光温生产潜力和气候生产潜力的时空分布特征,并结合现实生产力数据分析了气候变化背景下四川省水稻的增产潜力。结果表明:1961—2010年四川省水稻生育期内光合生产潜力的空间分布呈北低南高中部最低,光温生产潜力呈现北高南低,气候生产潜力为南北低中间高。近50年来日照时数的减少使得水稻光合生产潜力从20世纪80年代开始持续偏低;温度的升高有利于水稻光温生产潜力的增加,尤其在2006年出现高值;降水量的减少使水稻气候生产潜力从20世纪90年代开始下降明显。四川省水稻存在增产潜力,但增产潜力呈下降趋势,未来应加大农业科技投入,合理利用气候资源,提升水稻生产力。

Potential productivity of rice in Sichuan Province in recent five decades

Climate change has significantly influenced agricultural production in Sichuan, a main grain producing region in China. Scientific evaluation of the impact of climate change on rice production is crucial for sustainable development of regional agriculture. In this study, daily meteorological data for the period 1961?2010 from 45 weather stations were collected along with phenological data of rice for the period of 1981?2010 in order to analyze the temporal and spatial distributions of potential productivity of rice in Sichuan. The whole area of Sichuan was divided into 8 regions, including 7 rice growing regions and one non-rice growing region. Photosynthetic potential productivity, light-temperature potential productivity and climate potential productivity of rice in each region were calculated and the corresponding spatial and temporal variations analyzed. The improvements in potential yields of rice were further analyzed by comparison of potential productivity to actual yield. The results showed that while photosynthetic potential productivity was high in the southern Sichuan, it was low in central Sichuan. Light-temperature potential productivity was high in the northern and low in the southern regions. Climate potential productivity was high in central Sichuan and low in the northern and southern regions. Decreasing sunshine hours in the last five decades led to the declines in rice photosynthetic potential productivity since the 1980s. Temperature increase benefited light-temperature potential productivity of rice and the peak value of light-temperature potential productivity was in 2006. Precipitation was one of the main limitations and decreasing precipitation resulted in low climate potential productivity since the 1990s. A significant gap was noted between potential productivity and actual yield and the potential for improving rice yield declined with the decades. There was urgent need to develop science and technology in order to make better use of the climate resources and raise the yield of rice in the study area.