School of Economics, Hebei University, Baoding 071000, China.
Center of Resources Utilization and Environmental Conservation, Hebei University, Baoding 071000, China.
Int J Environ Res Public Health. 2022 May 28;19(11):6612. doi: 10.3390/ijerph19116612.
Chemical fertilizer is one of the most important input factors in agricultural production, but the excessive use of fertilizer inevitably leads to the loss of agricultural eco-efficiency (AEE). Therefore, it is necessary to explore the impact of fertilizer use intensity (FUI) on AEE. However, ordinary panel regression, based on the assumption of parameter homogeneity may yield biased estimation conclusions. In this regard, a panel quantile regression model (QRM) was constructed with the provincial panel data of China from 1978-2020 to test the difference and variation of this impact under heterogeneous conditions. The model was then combined with the spatial econometric model to explore the effect of the spatial lag factor. The results are as follows: (1) The QSM has unveiled a great improvement space for AEE that remains low overall, despite displaying a rising trend; the highest AEE is in the eastern region. (2) The FUI has a significant negative effect on AEE with the rise in quantiles, this negative effect tended towards weakening overall, although it rebounded slightly; it was stronger in areas with low AEE. It is necessary to consider the heterogeneous conditions in comparison with the average treatment effect of ordinary panel econometric regressions. (3) The impact of FUI shows significant variability in different economic sub-divisions and different sub-periods. (4) After considering the spatial effect of fertilizer use, the negative influence on local AEE had a faster decay rate as the quantile rose, but could produce a positive spatial spillover effect on AEE in neighboring areas. Local governments should dynamically adjust and optimize their fertilizer reduction and efficiency improvement policies according to the level and development stage of their AEE to establish a complete regional linked agroecological cooperation mechanism.
化肥是农业生产中最重要的投入要素之一，但化肥的过量使用不可避免地导致了农业生态效率（AEE）的损失。因此，有必要探讨肥料利用强度（FUI）对 AEE 的影响。然而，基于参数同质性假设的普通面板回归可能会产生有偏估计结论。在这方面，利用中国 1978-2020 年的省级面板数据构建了面板分位数回归模型（QRM），以检验在异质条件下这种影响的差异和变化。然后，将模型与空间计量经济学模型相结合，以探索空间滞后因素的影响。结果如下：（1）QSM 揭示了 AEE 仍有很大的提升空间，尽管呈上升趋势，但总体上仍处于较低水平；AEE 最高的是东部地区。（2）FUI 对 AEE 有显著的负向影响，随着分位数的上升，这种负向影响总体上趋于减弱，尽管略有反弹；在 AEE 较低的地区更为强烈。与普通面板计量回归的平均处理效应相比，需要考虑异质性条件。（3）FUI 的影响在不同的经济细分和不同的子时期表现出显著的可变性。（4）在考虑肥料使用的空间效应后，随着分位数的上升，对当地 AEE 的负向影响衰减速度加快，但对邻近地区的 AEE 会产生正向空间溢出效应。地方政府应根据其 AEE 的水平和发展阶段，动态调整和优化其减少肥料和提高效率的政策，建立完整的区域关联农业生态合作机制。
