Areas of cropland, total sown area of crops, grain sown areas in main grain producing areas in China were analyzed based on statistical data from 1979 to 2008, and the quantitative relation model of maximum crop index, heat, and water resources was applied to calculate and analyze the theoretical and excavatable potential of multiple cropping index, to study the change characteristics and potential of multiple cropping index, develop the grain producing ability, and guarantee the stability of grain production in these areas. The results showed that the areas of cropland was decreased, grain sown areas increased, total grain output and yield per unit area increased, accounting of total grain output for the proportion increased, and multiple cropping index in Northeast and Huanghuaihai region increased but decreased in mid-lower reaches of Yangtze River from 1979 to 2008. The theoretical excavatable potential of Northeast, Huanghuaihai region, and mid-lower reaches of Yangtze River was 28％, 48％, and 94％refer to the multiple cropping index of cropland in 2008.%为了解粮食主产区耕地复种指数变化特征与潜力,进一步挖掘粮食主产区的生产能力,稳定全国粮食安全大局,利用1979-2008年统计资料,对我国粮食主产区耕地面积、农作物总播种面积、粮食播种面积进行分析,并采用最大复种指数与热量、水资源之间的定量化关系模型,分析粮食主产区的复种指数理论潜力和可挖掘潜力.结果表明:1979-2008年期间我国粮食主产区耕地面积减少,农作物播种面积增加,粮食总产量与单产攀升,粮食总产量占全国比重升高,耕地复种指数东北区、黄淮海区上升,长江中下游地区下降.以2008年的耕地复种指数为参照,东北区、黄淮海区、长江中下游区理论可挖掘潜力分别为28%、48%、94%.
展开▼
