耕地利用视角下全国粮食生产时空特征演变

为综合考虑耕地数量及各项因素对粮食生产的影响,基于对数平均迪式分解方法(LMDI)将影响粮食产量的因素分解为耕地面积、复种指数、种植结构和粮食单产四大因素,研究1996—2016年其对全国粮食产量变化的作用机制。结果表明:1)我国耕地数量持续减少,空间上呈现南部地区减少、北部地区增加的趋势,导致全国粮食产能重心北移。2)粮食单产、复种指数这些技术因素均是促进因素,其中单产提高对总产量提升贡献最大;期间耕地面积下降与种植结构调整则是粮食产量的抑制因素。研究认为,城市化过程中耕地面积减少不可避免,保证粮食安全不但需要严格保护耕地,而且必须强化"藏粮于技"战略实施,不断提高粮食单产与复种指数,以稳定与优化粮食生产。

Evolution of spatio-temporal characteristics of grain production in China from the perspective of arable land use

In order to comprehensively consider the impact of the amount of arable land and other factors on food production,this study used LMDI approach and decomposed the factors of arable land utilization for grain production into 4 factors including arable land area,multiple crop index,planting structure and intensive cultivation.And studying the mechanism of changes in national food production from 1996 to 2016.The results showed that:1) The amount of arable land area in China continued to decrease and the spatial characteristics were the decline in the southern region and the increase in the northern region,which had also brought a significant shift in grain production capacity to the north.2) Grain yield per unit and the multiple cropping indexes were all the factors that promoted production,among which,the increase in grain yield per unit contributed the most to the increase in total grain production.The decline of arable land area and the adjustment of planting structure during the period were the factors that reduced grain production.The results obtained from this study suggests that in the process of urbanization,the reduction of arable land is unavoidable.To ensure food security,it is necessary not only to strictly protect arable land,but also to strengthen the strategic measures for storing grain in technology and continuously improve the grain yield per unit and multiple crop index to stabilize and optimize grain production level.