机械化与粮食增产：直接影响还是间接影响?*——基于5类品种的实证

MECHANIZATION AND FOOD PRODUCTION:DIRECT OR INDIRECT EFFECTS? *——EMPIRICAL EVIDENCE BASED ON FIVE TYPES OF FOOD

关键词:  农业机械化粮食产量空间自相关空间杜宾模型农机市场

Key words:  agricultural mechanization  grain yields  spatial autocorrelation  Spatial Durbin Model  agricultural machinery market

摘要:

［目的］依据要素流动视角，探究在空间维度下，农业机械化发展对不同的粮食品种是否存在推动当地粮食增产的直接效应和带动其他地区粮食增产的间接效应。［方法］将粮食分为水稻、小麦、玉米、豆类、薯类5类不同的品种，基于2000—2015年的省级面板数据，首先采用Moran′s I指数检验空间自相关性，再运用空间杜宾模型估计直接效应、间接效应和总效应。［结果］（1）机械化发展存在推动当地小麦和薯类增产的直接效应，存在带动其他地区的稻谷、小麦、豆类、薯类增产的间接效应； 分2000—2007年和2008—2015年两个时间段先后观察，机械化发展对小麦的直接效应和薯类的间接效应发生了从不显著到显著的变化。（2）机械化发展对豆类增产的直接效应变为不显著，而间接效应变得显著； 机械化尚未显著促进玉米增产； 所有模型中的播种面积变量都显著影响粮食产量。［结论］(1)未来重点关注农机对玉米产量的作用，加大该类农机的研发； (2)注重耕地保护在粮食产量的基础性作用；(3)考虑到农机外包等新时代的特点，调节农机生产，推动农机市场的供给侧改革。

Abstract:

Based on the factor mobility perspective, this paper aims to explore whether the mechanic development of agriculture is able to be created a direct effect upon the grain yield increase of the local area, or an indirect effect of driving the grain yield increase of other areas under the spatial dimension. This paper divided grains into five different categories of rice, wheat, corn, beans and potatoes. Based on the provincial panel data from 2000 to 2015, the Moran′s I index was used to test its spatial autocorrelation and then Spatial Durbin Model was used to estimate the direct effect, indirect effect and total effect. The results showed that the grain yield increase of grain and potatoes were driven by the direct effect of mechanic development. In addition, the grain yield increase of rice, wheat, beans and potatoes were driven indirectly overall; based on two consecutive periods, from 2000 to 2007 and from 2008 to 2015, the direct effect on wheat and the indirect effect on potatoes experienced a switch from being indistinctive to significant due to the mechanic development of agriculture. The direct effect of the grain yield increase of beans was shifted to be not significant and the indirect effect had become significant; mechanic development had no effect on the grain yield increase of maize significantly; the yields were all influenced significantly by the variables of sown areas in all the models. Based on the above results, three conclusions can be drawn: (1) In the future, the research of farming machinery for corn yield should be paid more attention to, and the research and development of corn machinery needs to be promoted ; (2) The fundamental impact of cultivated land protection for the increase of grain yield needs to be emphasized; (3) The characteristics of the new era such as agricultural machinery outsourcing should be considered, thus adjusting the production of the machinery and promoting the supply side reform of the farm machinery market.