ABSTRACT
This study examined effect of climate variability on cassava yield in Ajasse-Ipo. To achieve this aim, this study examined trend of climatic elements of rainfall, minimum and maximum temperature, and relative humidity over the years; examined trend of cassava yield over the years; determined effect of climate variability on yield of cassava and finally predicted future trend of climate variables and their effect on cassava yield. Time series data on climatic elements: rainfall (mm), relative humidity (%), minimum and maximum temperature (oC) for fifteen years from Adesoye College Weather Station, Offa, Kwara State while cassava production yield record was collected from Agricultural Development Project, Ilorin. Descriptive and inferential analytical methods were used in analysing and interpreting the obtained data. Trend lines and graphs were used to examine trend of climatic elements and crop yield for fifteen years. Also correlation analysis was used to determine relationship between climatic elements and cassava yield, while multiple regression analysis was used to determine percentage contribution of each of climatic elements to cassava yield for fifteen years. Findings revealed rainfall fluctuates throughout this period, temperature fluctuates in values such that maximum temperature increased faster than minimum temperature. Also projection of year 2015-2024 revealed a steady decrease in rainfall while other elements would experience a steady increase. So, this study recommended farmers should go back to cultural farming practices to conserve soil water and cool down ambient temperature that affects growth of crops on the farm.
TABLE OF CONTENTS
Pages
TITLE PAGE……………………….……………………………....................i
LIST OF ABBREVIATIONS/SYMBOLS…………………………………....ii
ABSTRACT………………………….…………………………………..........v
DEDICATION……………………….…………………………………..........vi
ACKNOWLEDGEMENT…………….………………………………………vii CERTIFICATION………………….……………………………………….....viii
TABLE OF CONTENTS…………………………….………………..............ix
LIST OF TABLES………….………………………………………………....xiii
LIST OF ILLUSTRATIONS (FIGURES)…………………………………….xiv
LIST OF APPENDICES……………………………………………………....xv
CHAPTER ONE………………………………....……………………………1
1.0 INTRODUCTION…………………………………..………………..1
1.1 Background to the Study…………………………….………….........1
1.2 Statement of the Problem……………….……………………………4
1.3 Aim and Objectives of the Study……………………………..……...6
1.4 Justification of the Study………………………………………..........6
1.5 Scope of the Study……………………………………………............7
1.6 Study Area……………………….…………………………………...7
1.6.1 Location and Size………………………..………………………....7
1.6.2 Relief……..………………………………………………………...8
1.6.3 Climate…………………………..…………………………………9
1.6.4 Soil……………………………..…………………………………..10
1.6.5 Socio-Economic Activities……..………………………………….10
1.6.5.1 Agriculture………………..……………………………………...10
1.6.5.2 Commerce………………………………..…………………........11
1.6.5.3 Socio-Cultural…………………..……………………..................12
CHAPTER TWO………………………………..………………………........13
2.0 CONCEPTUAL FRAMEWORK AND LITERATURE
REVIEW……………..........................................................................13
2.1 Conceptual Framework…………………..…………………………..13
2.1.1 Climate System……………………………………………..……...13
2.1.2 Hydrological Cycle-Climate Relationship………..………………..20
2.2 Literature Review………………………………….…………………21
2.2.1 Climate Variability…………………….…………………………...21
2.2.2 Causes of Changes in Climate Variability……..…………………...22
2.2.2.1 Global and Hemispheric Variability…………..…………….........23
2.2.2.2 Solar Radiation/Solar Output………………………..…………...24
2.2.2.3 Feedbacks and Non-Linearities……….…………………….........25
2.2.2.4 The Enhanced Green House Effect………………..……………..26
2.2.2.5 Land-Use Change………………………………………………...28
2.2.3 Evidence for Climate Change and Variability in the Present,
Past and the Predictions for the Future………..................................29
2.2.3.1 Changing in Rainfall………………..……………………….........29
2.2.3.2 Change in Global Temperature……………..…………………….30
2.2.3.3 Sea Level Rise……………………….…………………………....31
2.2.3.4 Ice Sheets and Glacier…………………….……………………....33
2.2.4 Cassava: History and Characteristics......…..………………….........34
2.2.5 Climate Variability and Cassava Production……………..………...35
2.2.6 Government Intervention on Cassava Production in Nigeria……....38
CHAPTER THREE………………………………..…………………….........41
3.0 RESEARCH METHODS…………………..………...……………....41
3.1 Introduction……………………………………………..………........41
3.2 Data Required for the Study…………….…………………………....41
3.3 Sources of Data……………………..………………………………...42
3.4 Data Processing………………………………………….…………...42
CHAPTER FOUR………………………………….…………………............45
4.0 DATA PRESENTATION, ANALYSIS AND DISCUSSION
OF RESULTS………………………………………………………..45
4.1 Trend of Climatic Elements in Ajasse-Ipo for Year 2000-2014…......45
4.2 Crop Production Yield (Tons/Ha) in ’000 for Year 2000 – 2014……750
4.3 Effect of Climate Variability on Cassava Yield……………………...52
4.4 Projected Crop Yield for the Year 2015-2024……………………….56
CHAPTER FIVE………………………………………………………...........58
5.0 SUMMARY, CONCLUSION AND RECOMMENDATIONS
OF FINDINGS………………………….............................................58
5.1 Summary…………………………….………………………….........58
5.2 Conclusion…………............................................................................60
5.3 Recommendations…………................................................................60
REFERENCES………………………..............................................................62
APPENDICES………………………………………………..………….........65
LIST OF TABLES
Table Description Pages
Table 4.1: Climatic Data for Year 2000-2014……………...............…………45
Table 4.2: Crop Production Yield (Tons/Ha) in ‘000 2000-2014..……….......50
Table 4.3: Correlation of Crop Yield (Tons/Ha) and Climatic Elements…….52
Table 4.4: Percentage Contribution of each of the Climatic Element to
Cassava Yield from Year 2000-2014………………………….......53
Table 4.5: Equation of the Model…………………..………………………....55
Table 4.6: Projected Climatic Variables for Year 2015-2024………….……..57
