Conserving fertilizer in China's rural-agricultural development: The reversal shifts and the county-specific EKC evidence from Hubei

This paper examines China's fertilizer conservation in 1978–2017. The provincial data displays a positive reversal shift consistent to the Environmental Kuznets Curve (EKC) hypothesis in fertilizer application. The occurrences of applying less fertilizer but achieving higher farming output, is a positive signal for fertilizer conservation. Then we select Hubei as a case study for more county-specific examinations. To examine Hubei's 80 county-level areas in 2000–2017, we define an ecological impact index of fertilizer use as the local fertilizer application divided by the agricultural gross product. After passing the unit root tests, the panel regressions indicate the N-shaped EKC shift: Hubei's annual county-specific fertilizer-impact indexes rose first with the rural household income, and then declined before they started increasing again, while time effect also existed significantly in the samples. We advise local agricultural policy implementers keep multi-scalar measures and circular economy to conserve fertilizer-use, with more stakeholders engaging fertilizer conservation in rural areas.