Influence of El Niño-Southern Oscillation on Rainfall Variability and Cereal Crop Yields in Northwestern Nigeria

Abstract

This study assessed the influence of the El Niño-Southern Oscillation (ENSO) on rainfall variability and cereal crop yields using monthly rainfall data (1983–2024) sourced from the NASA Prediction of Worldwide Energy Resources; annual rice, millet and sorghum yield data (2000–2024) from the National Agricultural Extension and Research Liaison Services (NAERLS); and ENSO indices (1983–2024) obtained from NOAA. Rainfall anomalies were computed to characterise interannual variability, while linear regression and one-way analysis of variance (ANOVA) with eta-squared (η²) effect size were used to evaluate crop yield trends and ENSO effects. Annual rainfall averaged 862.26 mm (CV = 37.14%) and varied significantly among ENSO phases (F = 5.32, p = 0.0052), with pronounced wetter conditions during some La Niña years (2021 and 2022). Rice (p = 0.013) and millet (p < 0.001) yields exhibited significant increasing trends, whereas sorghum (p = 0.002) showed a slight significant decline. However, ENSO had no significant influence on all the yields. These findings indicate that ENSO is a significant driver of rainfall variability but a weak predictor of annual cereal yields, highlighting the need to integrate ENSO-based seasonal climate forecasts with climate-smart agricultural practices to strengthen agrometeorological advisory services.