Effect of Climate Change on Maize (Zea-mays) and Cassava (Manihot-esculenta) Yields in Selected States of South Eastern Nigeria

Agriculture is one of those activities of man that is greatly affected by climate. Therefore, a change in climate would in no small measure impact on agriculture, location notwithstanding. This work as a result examined the impact of climate change on maize and cassava yields in Southeastern Nigeria. Expost-facto research method in the context of quasi experimental research design was adopted for the study. Data for rainfall and temperature were obtained from Nigerian Meteorological Agency (NIMET); and those for crop yields came from Federal Ministry of Agriculture of Nigeria and Agricultural Development Programme (ADP) of selected states. The data were analyzed using descriptive statistics, multiple linear regressions and analysis of variance. Results showed that, there are evidences of climate change in Southeastern Nigeria, with notable fluctuations in the identified trends. Employing the trend analysis represented by the least square line, Abia State rainfall is increasing at 0.1026mm per annum, while Imo State is decreasing at -1.1255 mm per annum. All the states recorded positive slopes in mean temperature which shows an increase in their trends. The multiple regression model showed R2 values that ranged between 0.25 – 0.29 revealing that only 25 %- 29 % of cassava and maize yields could be explained by rainfall and temperature across the states and the result was significant at p<0.05 revealing that cassava and maize yields significantly depended on rainfall and temperature. Crop yields were also significantly different spatially. As a result of the findings the study strongly advocates, development of better and sustained environmental policies that will be beneficial to climate systems while creating sustainable food security.