城镇化对耕地利用强度的影响及中介效应分析

Effect of urbanization on agricultural land-use intensity and mediation analysis

关键词:  城镇化  耕地  利用强度  中介效应

Key words:  urbanization  agricultural land-use intensity  mediation analysis

摘要:

为探讨城镇化对耕地利用强度的影响及作用机制，利用31个省份(统计数据未含港、澳、台地区)1995—2018年的数据，分析城镇化对复种指数、化肥施用强度、粮食单产、种植业碳排放强度等4个耕地利用强度指标的影响，并对土地经营规模、城镇扩张、城镇人口、居民消费水平、城乡收入差距等因素进行中介效应分析。结果表明:1)城镇化对农业生产具有土地规模效应、劳动力替代效应和需求拉动效应，进而影响耕地利用强度。总体上，城镇化对化肥施用强度和粮食单产具有正向影响，对复种指数和种植业碳排放强度没有显著影响。2)城镇化有利于扩大土地经营规模，从而有利于提高复种指数，降低化肥施用强度和碳排放强度，同时不影响粮食单产；城镇化造成农业劳动力的相对稀缺，从而导致其他投入要素对劳动力的替代，以及复种指数的下降；居民消费水平的提高对各个耕地利用强度指标都产生正向影响。

Abstract:

To investigate the effect of urbanization on agricultural land-use intensity and its mechanism, using the data of 31 provinces(The data do not include those of Hong Kong, Macao and Taiwan regions)from 1995 to 2018, this study analyzes the impact of urbanization on four indicators of agricultural land-use intensity, including multiple cropping index, fertilizer use intensity, grain output per unit area, and carbon emission intensity of crop production, and analyzes the mediation effect of land scale, urban expansion, urban population, resident consumption level, and urban-rural income gap. The results show that: 1)Urbanization has land scale effect, labor substitution effect and demand pull effect on agricultural production, which in turn affects agricultural land-use intensity. In general, urbanization has a positive impact on fertilizer use intensity and grain yield per unit area, but has no significant impact on multiple crop index and carbon emission intensity. 2)Urbanization can promote the expansion of land scale, which can increase multiple cropping index, reduce fertilizer use intensity and carbon emission intensity, without affecting the grain yield. Urbanization causes the relative scarcity of agricultural labor force, which leads to the substitution of other inputs for labor force, and the decline of multiple cropping index. The increase in the level of residents' consumption has a positive impact on the four indicators of agricultural land-use intensity.