Impact of urbanization on pollution-related agricultural input intensity in Hubei, China

Agricultural input intensity increases significantly during the rapid urbanization in China, which has contributed to the increasingly serious non-point pollution. Using the vector autoregression (VAR) model, this study analyzes the impact of urbanization on pollution-related agricultural input intensity in Hubei, China. Results of an impulse response function analysis reveal that pesticide use intensity continues to rise following shocks from the urban population proportion and the secondary and tertiary industry proportion. Responses of chemical fertilizer intensity first decrease and then increase subjected to the shocks from the urban population proportion and secondary and tertiary industry proportion. The intensity of agricultural plastic film use first increases and then decreases when receives the shocks from the urban population proportion which is the opposite to the response to the shock from the secondary and tertiary industry proportion. In addition, the responses of pesticide use intensity, chemical fertilizer use intensity and agricultural plastic film use intensity trend decrease following their own shocks after positive initial responses. The variance decomposition results demonstrate that the shocks due to pesticide use intensity, chemical fertilizer use intensity and agricultural plastic film use intensity generally explain the largest proportion of their own variation over the 10-year horizon. However, an increase in the urban population proportion plays a critical role in determining the variations of pesticide use intensity in late periods, it account for 56.88% the variations in the tenth period. And the contribution of the urban population proportion to the variations in agricultural plastic film use intensity increases consistently, it account for 33.74% of the variations in the tenth period. Therefore, the hidden drivers of these phenomena need to be further understood regarding the relationships between urbanization and diffuse pollution from agricultural production.