西南地区耕地复种指数变化特征和发展潜力分析

Changing Characteristics and Developmental Potentials on Multiple Cropping Index of Arableland in Southwestern China

耕地复种指数是耕地利用集约程度的一个量化指标。基于1978～2007年统计资料,对西南地区耕地面积、农作物总播种面积、粮食播种面积和耕地复种指数的变化特征进行了分析,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计算分析了该地区的复种指数理论潜力和可挖掘潜力。结果表明:1978年以来西南地区耕地面积不断下降,农作物总播种面积总体上呈上升态势,耕地复种指数也在缓慢上升。与此同时,西南地区粮食播种面积总体上在减少,粮食播种面积占农作物总播种面积的比重也不断减少。在现有基础上西南地区复种指数可挖掘潜力为36.1%,其中最大的是云南,其次是广西、四川、重庆和贵州,分别为45.2%、44.0%、42.0%、40.4%和25.0%。加强农业基础设施建设,提高农业机械化水平,发展多样化立体种植模式,是提高西南地区耕地复种指数的有效措施。

Multiple cropping index （MCI） is a very impotent quantitative indicator in the intensity of arableland use. Based on the statistical data from 1978 to 2007, this paper analyzes the change of the total area of arableland, crops, grain and the MCI in Southwestern China, and the maximum and potential of MCI in each province （municipality, autonomous region） of Southwestern China are calculated by using the model of the quantitative relationship between the maximum of MCI and the heat and water resources. The conclusions are as follows： the arableland area, grain sown area and its proportion have decreased, but the total sown area of crops and MCI have increased in Southwestern China since 1978. According to the calculation results, the potential of MIC could be improved by 36.1% on the basis of the current index. However, on regional scale, the potential of arableland MCI varied across provinces. Compared with others, the potential of Yunnan province is the largest one with 45.2% to be improved, followed by Guangxi, Sichuan, Chongqing and Guizhou, with 44.0%, 42.0%, 40.4% and 25.0% respectively to be improved. In order to increase the MCI in these regions and to achieve the goal of regional food security, the local government should take more effective measures such as strengthening the agricultural infrastructure construction, improving the level of agricultural mechanization, and developping three-dimensional diversification of cropping patterns.