1978~2014年间中国玉米生产的时空特征变化研究

［目的］厘清中国玉米生产的时空变化特征,有助于保障玉米的持续、稳定供应。［方法］文章采用经验模态分解等方法,基于玉米总产、播种面积及单产3个指标,从全国和省域两个尺度系统分析1978~2014年中国玉米生产的时空特征。［结果］（1）研究期间,全国玉米产量增加了1.60亿t,其波动量呈现先增大后减小的趋势,波动指数的变化幅度不大; 玉米播种面积增加了1716万hm2,其变化趋势与玉米总产量的变化趋势基本一致;玉米单产从1978年的2802.7kg/hm2波动性增至2014年的5809.1kg/hm2,总体波动幅度大于玉米播种面积和总产量的波动幅度。（2）研究期间,省域玉米增加量呈现出“北高南低”的特征,中国玉米生产重心进一步北移;省域玉米播种面积增加量呈现出“北高南低”“西高东低”的特征,东北区和华北区的玉米播种面积进一步扩大;省域玉米单产增加量呈现出“西高东低”“北高南低”的特征,省域单产以趋势增长为主,但年际间的波动较剧烈。［结论］1978~2014年,省域间玉米生产分异特征明显,建议制定差别化的玉米生产策略。

SPATIAL-TEMPORAL CHARACTERISTICS OF MAIZE PRODUCTION IN CHINA DURING 1978~2014

Maize plays an important role in China''s agricultural production and national economy. Clarifying the spatial and temporal characteristics of maize production in China is helpful to ensure the sustainable and stable supply of maize. Based on the empirical mode decomposition method, etc, this paper systemically analyzed the change trend of China''s maize yield in 1978~2014 on the national and provincial scale. The results showed that: (1) Over the past 37 years, maize yield increased by 160 million t, the proportion of corn production in total grain production also increased from 18.36% in 1978 to 35.53% in 2014; maize planting area increased by 17.16 million hm2, which had almost the same change trend as the total grain yield; the yield of maize per unit increased from 2802.7kg/hm2 in 1978 to 5809.1kg/hm2 in 2014, the index fluctuation remained essentially between -5%~5%, the overall fluctuation was greater than that of the total maize yield and the maize planting area. (2) Over the past 37 years, provincial maize yield increased highly in the north and low in the south, while the provincial maize planting area showed the characteristics of "high in the north and low in the south. The maize planting area further enlarged into the Northeast and the Huanghuai region. The provincial maize per unit yield showed the characteristics of low in the east and high in the west. The fluctuation range of maize per unit yield was greater than that of maize sown area and maize yield. The results can provide a reference basis to compile differentiation maize production strategy.