Effects of temporal changes in climate variables on crop production in tropical sub-humid South-western Nigeria
Climate variability and change have been implicated to have significant impacts on global and regional food production particularly the common stable food crops performance in tropical sub-humid climatic zone. However, the extent and nature of these impacts still remain uncertain. In this study, records of crop yields and some climatic variables for a period of 17 years (1990 - 2006) were used to carry out a comprehensive study of the impacts of climate variability on some common classes of food crops (tubers, grains, legumes and vegetables) in South-western Nigeria with a view to determining their responses to observed varying climatic conditions. Crops differed markedly in their responses to the climate variables. Mean temperature varied with the tuber crop production compared with other food crops. Production of other food crops (grains, legumes and vegetables) was largely dependent on the seasonal and inter-annual change in rainfall. However, combinations of a number of interacting factors with both climatic and non-climatic components were responsible for the relatively low coefficient of correlation (r ≤ 0.4) between rainfall amount and the crop yields. The climate projections for Southwestern Nigeria by 2020 would have direct and adverse impacts on food production, distribution, infrastructure and livelihood assets in Nigeria.
Key words: Climate variability, crop yield and production, regional climate projections, South-western Nigeria