Spatial analysis of factors affecting fertilizer use efficiency in China: an empirical study based on geographical weighted regression model.

Improving fertilizer use efficiency (FUE) is an effective means to reduce fertilizer use and environmental contamination. Few studies have considered spatial effects of FUE and its determinants. This paper calculates the FUE of agricultural production by adopting panel data on 31 provinces in China from 2007 to 2017 using a stochastic frontier method and discusses the spatial distribution and characteristics. Furthermore, the geographical weighted regression (GWR) model is employed to examine the spatial impact of education level, non-agricultural employment ratio, disaster ratio, and farmers' income on FUE and reveal the spatial dispersion and agglomeration effect of different provinces in 2007, 2010, 2013, 2015, and 2017. The results show that the average FUE in China is 0.747 and has a significant decreasing trend, and FUE has a significant regional difference and spatial positive correlation in different provinces. Non-agricultural employment ratio is the most leading factor for increasing FUE for all provinces in studied years, and its influence degree shows a decreasing trend from southeastern to northwestern in each year. The different agricultural industry development modes, planting structure adjustment, and policy incentive systems for increasing non-agricultural employment ratio should be developed for different regions. Farmers' income has a significant negative impact on FUE, but the influence degree decreases annually, indicating that improving income to higher than turning point of the environmental Kuznets curve plays a critical role in improving FUE. The influence of education level on FUE is positive but relatively weak, and the influence degree declines from the western to eastern areas. It should strengthen the exploration of scientific and rational education and a training policy system to improve the educational level in different regions on the basis of local characteristics. Disaster ratio has a positive impact on FUE but is unstable. For the neighboring provinces, coordinated weather and possible disaster forecasting and release mechanism should be carried out based on the extent of the disaster.