EFFECTS OF CLIMATE CHANGE ON CASSAVA PRODUCTION IN EDO STATE, NIGERIA

Abstract

The study examined the effects of climate variability on cassava production in Edo-State, Nigeria. The specific objectives of the study were to describe the socio-economic characteristics of cassava farmers in Edo-State; examine the perception of the respondents on climate change; determine the long run relationship between cassava output and climate change variables and identify the coping strategies adopted by cassava farmers in adjusting to effects of climate change. Primary and secondary data were used for this study. Primary data were generated using well-structured questionnaire. A total of 150 cassava farmers were selected using a multi-stage sampling technique. Secondary data involving time-series data spanning from 1995-2014 on climate variables (rainfall, temperature, relative humidity, sunshine hours, and solar radiation) were sourced from Nigeria Institute for Oil Palm Research (NIFOR), Edo-State while data on cassava yields were sourced from the National Bureau of Statistics (NBS), Edo state. Descriptive statistics were employed to discuss the socio-economic characteristics of the respondents. Results revealed that farm operations were dominated by old people with a mean age of 54 years, and about 58.7% of them were males. Results also showed that the farmers had large household sizes with a mean household size of 7.8. The farmers operated small farm holdings having a mean farm size of 2.8 acres. The study also revealed that majority (80%) of the farmers had farming experience of above 10 years. The farmers also had perceptions about climate change based on their experiences of observed fluctuations of climatic variables. The farmers perceived that the intensity of the sun was high and that there were high degrees of temperature and frequent rainfall. Secondary data containing the Time-Series data for climate factors (Rainfall, Temperature, Sunshine Hours, Solar radiation and Relative Humidity) were analyzed using co integration model. The result of co-integration analysis confirmed that there exists a long- run equilibrium relationship among the variables. The climatic variables have influence on cassava yield in the study are. The result of the ECM showed that all the lagged values of the climate variables except solar radiation and relative humidity are revealed to exert positive effect on cassava yield. However, only the coefficients of Sunshine hours and relative humidity were significant at 5% and 10% levels respectively. This result implies that a unit increase in the levels of these variables will increase cassava yields. For example, a unit increase in rainfall will increase cassava yield by 0.0568units. A unit increase in solar radiation will decrease cassava yield by 0.1031units. Also, a unit increase in sunshine hours will increase cassava yield by 0.2154 units, a unit increase in temperature will increase cassava yield by 0.6827units. A unit increase in relative humidity will lead to about 0.6124 increases in cassava yield. This result can be explained in view of the fact that for example, normal temperature has the tendency to regulate crop and soil interactions thereby making soil nutrient available to crops. Generally speaking, rainfall is considered to have important and positive effect on cassava yield. The positive effect of rainfall on cassava yield is to the extent when rainfall has not resulted into flooding as this will bring about negative effect of previous year rainfall on cassava yield. Heavy rainfall of previous year for example may lead to erosion and leaching. Consequently, there is insufficient nutrient for the current cropping season. The co-efficient of the error correction term [EC(-1)] indicates the speed at which cassava yields adjust in the long run to its main determinant factors in the short run. The speed of adjustment (0.02%) is negative but not significant at 5% level.