基于LMDI模型的化肥施用量时空特征与驱动机制分析

临沂市化肥施用量近年来一直处于下降趋势，但化肥施用强度仍未达到国家和国际标准。基于临沂市2010—2019年的面板数据，利用灰色GM(1,1)模型预测临沂市未来化肥施用强度趋势，评价临沂市化肥施用情况，计算达到国家和国际标准所需年限；采用弹性脱钩模型分析临沂市化肥施用与农业增长关系变化；运用LMDI分解模型将临沂市化肥施用分解为规模效应、结构效应、市场效应、效率效应，计算出各效应的贡献值，从而提出临沂市化肥减量驱动机制，为临沂市化肥减量提供理论指导。结果表明：临沂市化肥施用强度到2027年达到国家标准，到2030年达到国际标准；临沂市弹性脱钩系数近10年除2016—2018年为扩张性联结外，其他年均已达到绝对脱钩，且各县区大部分已绝对脱钩，说明临沂市及其各县区近年来的农业产值与化肥施用量变化关系较小。对临沂市化肥减量起主要作用的是市场效应（负效应）和效率效应（正效应），而规模效应和结构效应对临沂市化肥减量的影响程度较小。因此，应坚定不移地致力于提高化肥效率、加大农业投入、加强农户施肥培训、改善种植结构。

Analysis of Spatial-temporal Characteristics and Driving Mechanisms in Fertilizer Application Based on LMDI Model

The application amount of chemical fertilizer in Linyi City has been in a downward trend in recent years, but the application intensity of chemical fertilizer has not reached the national and international standards. Based on the panel data of Linyi City from 2010 to 2019, the grey GM (1,1) model was used to predict the future trend of chemical fertilizer application intensity in Linyi City, the application of chemical fertilizer in Linyi City, and the years required to meet national and international standards were calculated.The elastic decoupling model was used to analyze the relationship between chemical fertilizer application and agricultural growth in Linyi City. The LMDI decomposition model is used to decompose the chemical fertilizer application in Linyi City into scale effect, structure effect, market effect and efficiency effect, calculate the contribution value of each effect, and put forward the driving mechanism of chemical fertilizer reduction in Linyi City, so as to provide theoretical guidance for chemical fertilizer reduction in Linyi City. The results show that the application intensity of chemical fertilizer in Linyi City will reach the national standard by 2027 and the international standard by 2030. The elastic decoupling coefficient of Linyi City has reached absolute decoupling in recent ten years, except for the expansionary connection from 2016 to 2018, and most counties and districts have been absolutely decoupled, indicating that the agricultural output value of Linyi City and its counties and districts has little relationship with the change of chemical fertilizer application in recent years. The main effects of fertilizer reduction in Linyi are market effect (negative effect) and efficiency effect (positive effect), while scale effect and structure effect have little impact on fertilizer reduction in Linyi. Therefore, we should unswervingly strive to improve the efficiency of chemical fertilizer, increase agricultural investment, farmers'' fertilization training and improve the planting structure are necessary.