Climate Dynamics, Fertilizer use, and Cassava Output in Nigeria: A Four-Decade Trend Analysis (1980 – 2023)

Abstract

This study investigated the trends in climatic variables, fertilizer use, and cassava production in Nigeria from 1980 to 2023, utilizing exponential trend analysis on secondary data sourced from the Food and Agriculture Organization (FAO) statistics, the World Bank database, the National Bureau of Statistics (NBS), and the Nigerian Meteorological Agency (NiMet). Results indicated a slight but significant decline in rainfall (β = -0.0021, p < 0.01) and cassava yield (β = -0.0094, p < 0.01), alongside significant temperature increases (β = 0.0037, p < 0.01), relative humidity (β = 0.0027, p < 0.01), solar radiation (β = 0.0154, p < 0.01), cultivated land area for cassava (β = 0.0052, p < 0.01), and labour force involved in cassava production (β = 0.2599, p < 0.01). Fertilizer use showed a negative but statistically insignificant trend (β = -0.0392, p > 0.05). These findings suggest that, despite increasing land and labour inputs, as well as expanding solar radiation and humidity, cassava yields are declining, likely due to decreasing rainfall, rising temperatures, and inadequate fertilizer application. The study concluded that climate variability, coupled with limited technological adoption as exemplified in low fertilizer use, threatens cassava productivity in Nigeria. It recommends urgent investment in climate-smart agricultural practices, enhanced access to fertilizers, and the promotion of drought- and heat-tolerant cassava varieties to bolster resilience and sustain production.