农地经营规模与财政支农政策对农业碳排放的影响

本文利用2000—2016年中国省级动态面板数据,构建有调节的中介效应检验模型,对农地经营规模影响农业碳排放的作用机制进行了实证检验。研究结果表明：①农地经营规模对农业碳排放既具有直接影响,也产生间接影响;②直接影响体现在“规模效应”：农地经营规模与农业碳排放之间呈现“U”型变化趋势;间接影响是通过影响农地利用方式来体现的：农地经营规模与种植结构、化肥投入强度之间均呈现“U型”关系,与农业机械投入强度之间呈现“倒U型”关系,种植结构、农业机械投入强度的提高抑制了农业碳排放,化肥投入强度的提高促进了农业碳排放;③财政支农政策在种植结构、化肥投入强度对农业碳排放的影响中起到显著的调节作用,较高的财政支农支出水平加强了粮食种植比例与农业碳排放之间的负向关系,削弱了化肥投入强度与农业碳排放之间的正向关系。因此,为促进农业低碳发展,一方面要适度扩大农地经营规模,加强对农地利用方式的科学管理;另一方面要持续加大对农业的财政支持,进一步优化调整农业财政补贴结构。

The impact of farmland management scale and fiscal policy for supporting agriculture on agricultural carbon emission

Based on the dynamic panel data of the provinces in China’s mainland from 2000 to 2016, this study constructed a model of regulated mediating effects, and tested the impact of farmland management scale on agricultural carbon emissions. The results show that farmland management scale has both direct and indirect effects on agricultural carbon emissions. The direct impact is embodied in the “scale effect,” that is a U-shaped trend between farmland management scale and agricultural carbon emissions. The indirect influence is reflected by farmland utilization mode. The relationship between farmland management scale and planting structure or fertilizer input intensity is U-shaped, and that between the former and mechanical input intensity is inverted U-shaped. Planting structure and mechanical input intensity restrain agricultural carbon emissions while fertilizer input intensity promote that. Agricultural finance plays a significant regulatory role in the impact of planting structure or fertilizer input intensity on agricultural carbon emissions. Higher level of fiscal expenditure positively regulates the negative relationship between planting structure and agricultural carbon emissions, and negatively regulated the positive relationship between fertilizer input intensity and the latter. Therefore, in order to promote the low-carbon development of agriculture, on the one hand, it is necessary to appropriately expand the scale of farmland management and strengthen the scientific management of farmland utilization; on the other hand, it is advised to continuously increase the financial support for agriculture and further optimize the structure of agricultural financial subsidies.