Before revision:  In addition to finding  a good support for the existence of an environmental Kuznets curve for fertilizer application, it shows peculiar responses of N-fertilization to deviations from normal  conditions of moisture for each selected region, calling for ad hoc policy interventions.
After revision:  In addition to finding both spatial (in the form of knowledge spillover effects) and temporal dependences as well as a good support for the existence of an environmental Kuznets curve for fertilizer application, it shows peculiar responses of N-fertilization to deviations from normal conditions of moisture for each selected region, calling for ad hoc policy interventions.