Ex-ante and ex-post adaptation: Farmers’ fertilizer strategies for extreme weather events in China

This study investigates farmers’ fertilizer strategies as ex-ante and ex-post adaptations to extreme weather events in China. Using plot-level data from 778 maize farmers across three provinces collected in 2015 and 2018, we employ two-way fixed effects models to analyze how farmers adjust fertilizer quantity both before and during the growing season in response to floods, droughts, and windstorms. The results show that farmers increase ex-ante fertilizer application under flood risk but reduce input when anticipating drought and windstorm risks. After disaster shocks, they supplement fertilizer as an ex-post coping strategy. Heterogeneity analysis reveals that smallholders and nitrogen fertilizers are more sensitive to extreme weather, and that the effects of disaster severity are nonlinear and vary by disaster type. Mechanism analysis suggests that ex-ante fertilizer use can mitigate flood risk but may increase vulnerability to drought and windstorms, whereas ex-post use broadly aids recovery. Extended analysis uncovers a substitution effect between public interventions and private adaptation. These findings provide micro-level empirical evidence and policy insights for balancing food security and environmental sustainability amid rising extreme weather.