Assessing the Impact of Climate Change on Maize (<i>Zea mays</i>) and Cassava (<i>Manihot esculenta</i>) Yields in Rivers State, Nigeria

Abstract

Globally climate change has threatened agriculture and food security which is of great importance to the economy of a nation. In Nigeria it has become a great concern to the government and people because of the obvious changes in the climate systems, therefore, assessing the impact of climate change on crop yield in an oil producing state is of great importance especially where rain fed agriculture is the main determinant for crop yield. Expost-facto research method in the context of quasi experimental research design was adopted for the study. Data for rainfall and temperature and that for crop yields were obtained from Nigerian Meteorological Agency (NIMET) and federal ministry of Agriculture; Agricultural Development Program (ADP) respectively. Analysis of data was achieved using descriptive statistics, trend graphs and multiple linear regressions. Results showed that there had been a steady but gradual increase in the annual minimum, maximum and mean temperatures over the study period of thirty years and a decrease in rainfall. Mean temperature is increasing annually at the rate of 0.0253 per annum and rainfall is decreasing at the rate of -0.5817 mm per annum. The multiple regression model showed r 2 values of 0.28 for maize and 0.29 for cassava revealing that only 28% - 29% of maize and cassava yields could be explained by rainfall and temperature in the state and the result was significant at p < 0.05 revealing that cassava and maize yields significantly depended on rainfall and temperature. This study strongly advocates for a better and practicable environmental policies and improved agricultural techniques alternative source of water which will include irrigation farming, mulching since it is evident that there is a reduction in rainfall and increase in temperature in the state while creating sustainable food security.