Determination of Climate Change Impact on Growing Season Rainfall, Temperature and Crop Yields in Abia State, South-Eastern Nigeria

Climate Change poses a big threat to agriculture by altering the growing season of crops thereby resulting to serious danger to food production. The objective of this study is to determine the impact of climate change on growing Season Rainfall, Temperature on crop yield. Therefore, this work has examined the impact of climate change on the growing season of maize (Zea mays) and cassava (Manihot esculenta) yields in Abia State, South-Eastern Nigeria. The rainfall and temperature data were obtained from Nigerian Meteorological Agency (NIMET) and crop yield derived from the archives of the Federal Ministry of Agriculture (FMA) and Agricultural Development Program (ADP) for a period of 30 years which was analyzed using the descriptive statistics, trend graph, anomalies and regression model. Thus, correlational research method was adopted. The analysis showed increasing trend in annual mean maximum with 0.0205 per annum, mean minimum temperature with 0.0143 per annum and mean temperature with 0.0199 per annum while the annual growing season rainfall showed a decrease in trend with-0.3325 per annum. There has been a persistent increase in the mean temperature anomalies especially in the past five (5) years (2012–2016) and rainfall of recent years depicts a decrease anomaly in the last (10) years (2007-2016). The multiple regression model showed r2 values that ranged between 0.30 – 0.89 revealing that 30 % - 89 % of cassava and maize yields could be explained by rainfall and temperature in the states and the result was significant at p<0.05. It reveals that cassava and maize yields are significant depended on rainfall and temperature. The findings show that there is increase in temperature and decrease in growing season rainfall which needs serious attention as people in this part of Nigeria critically depend on rainfall for agricultural practice. It is recommended that government and private sectors should engage in farm irrigation and drilling of water borehole in farm sites as well as increase awareness of the farmers on climate change issues for sustainable food security of the nation.