Examining the Impact of Fertilizer Use, Economic Expansion, Methane Emissions, and Population Growth on Food Security in Nigeria

Food security remains a critical challenge in Nigeria. As a result, this research examines the impact of fertilizer use, economic expansion, population growth, and methane emissions on food security in Nigeria from 1970 to 2022. The methodologies used include the Autoregressive Distributed Lag (ARDL) model, Wald Test, and the Spectral Granger Causality test. The ARDL results demonstrate that in the long run, fertilizer use spurs food security, although not significantly, while population growth reduces food security insignificantly. On the other hand, economic expansion and agricultural methane emissions are positively associated with food security, likely reflecting scale effects of agricultural production rather than a direct beneficial role of emissions. In the short run, fertilizer use and methane emissions drive food security. The Wald Test also confirms the short-run findings. Furthermore, the Spectral Granger Causality test showed that fertilizer use and economic expansion Granger-cause food security in the long, medium, and short term. Population growth, however, Granger-causes food security only in the long term, while methane emissions Granger-cause food security in the medium and long term. Based on these results, policies are recommended, and their further implications are discussed.