This study explored spatial explicit multiple cropping efficiency(MCE) of China in 2005 by coupling time series remote sensing data with an econometric model-stochastic frontier analysis(SFA).We firstly extracted multiple cropping index(MCI) on the basis of the close relationship between crop phenologies and moderate-resolution imaging spectroradiometer(MODIS) enhanced vegetation index(EVI) value.Then,SFA model was employed to calculate MCE,by considering several indicators of meteorological conditions as inputs of multiple cropping systems and the extracted MCI was the output.The result showed that 46% of the cultivated land in China in 2005 was multiple cropped,including 39% doublecropped land and 7% triple-cropped land.Most of the multiple cropped land was distributed in the south of Great Wall.The total efficiency of multiple cropping in China was 87.61% in 2005.Southwestern China,Ganxin Region,the middle and lower reaches of Yangtze River and Huanghuaihai Plain were the four agricultural zones with the largest rooms for increasing MCI and improving MCE.Fragmental terrain,soil salinization,deficiency of water resources,and loss of labor force were the obstacles for MCE promotion in different zones.The method proposed in this paper is theoretically reliable for MCE extraction,whereas further studies are need to be done to investigate the most proper indicators of meteorological conditions as the inputs of multiple cropping systems.
【目的】分析近20年广西土地利用／土地覆盖变化（Land Use and Land Cover Change，LUCC）过程与气候波动对农田生产潜力的影响。【方法】基于20世纪80年代末至2010年的5期土地利用遥感监测数据，分析近20年广西耕地资源的变化过程；结合1990～2010年的逐日气象资料，采用环境因子逐步订正方法估算农田生产潜力。【结果】根据遥感监测结果，近20年广西耕地面积净减少了20843．81ha。在1990～2010年平均气候条件下，广西林地变耕地动态对农田生产潜力总值增加贡献最大，占新开垦耕地农田生产潜力总值的80．73％；耕地变建设用地动态使农田生产潜力总值减少最多，占流失耕地农田生产潜力总值的74．39％。当耕地保持20世纪80年代末状态不变时，气候波动使1990-2010年广西水田生产潜力均值变化总体上呈上升趋势，但旱地生产潜力均值变化总体上呈下降趋势。【建议】广西新开垦耕地的农田生产潜力不及流失耕地的农田生产潜力，优质耕地面积减少。因此要求在强调耕地占补平衡的同时，注重耕地质量的平衡，一方面要防止优质耕地面积的减少，另一方面要通过改土改水、节水灌溉等措施提高粮食综合生产能力，弥补由优质耕地减少和气候变化给粮食产量带来的损失。
