关键词: 粮食生产, LMDI方法, 耕地利用效应

Abstract:

There are four factors which denote four types of cultivated land use by drawing on grain production calculating model: grain yield per hectare (intensity effect), cultivated land area (scale effect), planting structure (structure effect) and multiple-cropping index (degree effect). Changes of grain production in China were thus studied by quantifying the contributions from changes in cultivated land use using LMDI method. The results showed: During 1978-2012, there was more aggregated intensity effect than degree effect on the total grain increment, while there was more structure effect than scale effect on the grain reduction. Intensity effect, the largest contributor for China's grain production all the time, decreased step by step, whereas degree effect, whittling down the production in the early phase, then turned to an indispensable promoting factor for its steadily uplift. Structure effect in weakening grain output increased over time, and scale effect expanded markedly from 1998 to 2012 because of the dramatic decline in cultivated area. Spatially, grain production in eastern coastal China was evidently shrinking when the northern and western inland experienced a compensating increase during 1996-2008. The higher positive intensity effect and degree effect were observed in the northern and western peripheral region, while the highly urbanized coastal region had the higher negative scale effect and structure effect, even in some cases with negative degree effect, thus enlarging the regional disparity of China's grain production. From the decomposition findings, the paper concluded with some suggestions for cultivated land use to enhance China's grain security.

Key words: LMDI, grain production, land use effects