THE EFFECTS OF CLIMATE CHANGE ADAPTATION STRATEGIES ON FOOD CROP PRODUCTION EFFICIENCY IN SOUTHWESTERN NIGERIA
This study examined the effects of climate change adaptation strategies on food crop production efficiency in Southwestern Nigeria. The study used multistage sampling technique and primary data were collected from 360 food crop farmers (i.e. 180 respondents were randomly selected from each selected state from the savanna and the rainforest agro-ecological zones that dominates the region). The analytical techniques involved descriptive and inferential statistics. Results of the multinomial logit analysis showed that household size negatively influenced the use of multiple crop varieties, land fragmentation (i.e. multiple farm plots), multiple planting dates and crop diversification. Age of household head had an inverse relationship with the choice and use of multiple crop varieties, land fragmentation (multiple farm plots), multiple planting dates and off-farm employment. Education had a negative effect on the choice and use of multiple crop varieties and multiple planting dates. Sex had positive influence on the choice and use of multiple crop varieties, multiple planting dates and off-farm employment but average distance had a positive relationship with the choice and use of land fragmentation. Tenure security positively influenced the choice and use of crop diversification but access to credit negatively correlated with multiple crop varieties, multiple planting dates and crop diversification. The stochastic frontier analysis showed that labour, farm size and other agrochemicals are highly significant at 1% level of probability in food crop production. The computed mean technical efficiency estimate was 0.84. The technical inefficiency model showed that land fragmentation (i.e. multiple farm plots) and multiple planting dates had significant positive relationship with technical inefficiency but years of climate change awareness and social capital had significant inverse relationship with it. The stochastic frontier profit function showed that rent on farm land and price of labour were highly significant at 1% level of probability. The computed average profit efficiency of the respondents was 0.67. The profit inefficiency model revealed that off-farm employment, multiple planting dates, crop diversification and education level had significant positive relationship with profit inefficiency but land fragmentation (i.e. multiple farm plots), years of climate change awareness and social capital had negative relationship with it. The factor analysis revealed that the major constraints to climate change adaptation among the food crop farmers were public, institutional and labour constraints; land, neighbourhood norms and religious beliefs constraints; high cost of inputs, technological and information constraints; farm distance, access to climate information, off-farm-job and credit constraints; and poor agricultural programmes and service delivery constraints. The study, therefore, recommends, inter alia, proactive regulatory land use systems that will make food crop farmers to participate in a more secured land ownership system should be put in place to enhance their investment in climate change adaptation strategies that has a long-term effect. Morealso, Government and non-governmental organizations should help the farmers in the area of provision and/ or facilitate the provision of input-based adaptation strategies in the study area. Again, intensive use of already proven adaptation strategies at farm-level by the farmers at their present resource technology will still make them to reduce technical and profit inefficiencies by 16% and 33% respectively, in the study area.
TABLE OF CONTENTS
Title page -- -- -- -- -- -- -- -- -- -- i
Approval page -- -- -- -- -- -- -- -- -- ii
Certification -- -- -- -- -- -- -- -- -- -- iii
Dedication -- -- -- -- -- -- -- -- -- -- iv
Acknowledgement -- -- -- -- -- -- -- -- -- v
List of Tables -- -- -- -- -- -- -- -- -- ix
List of Figure -- -- - - -- -- -- -- -- -- xii
Abstract -- -- -- -- -- -- -- -- -- -- xii
1.1 Background of the Study-- -- -- -- -- -- -- -- 1
1.2 Statement of the Problem -- -- -- -- -- -- -- 7
1.3 Objectives of the Study -- -- -- -- -- -- -- 9
1.4 Hypotheses of the Study -- -- -- -- -- -- -- -- 10
1.5 Justification of the Study -- -- -- -- -- -- -- 11
1.6 Limitation of the Study -- -- -- -- -- -- -- 12
2.0 LITERATURE REVIEW
2.1 Concept of Climate Change -- -- -- -- -- -- -- 13
2.2 Concept of Adaptation -- -- -- -- -- -- -- 14
2.3 Climatic trend in Nigeria -- -- -- -- -- -- -- 18
2.4 Conceptual Framework -- -- -- -- -- -- -- 20
2.5 Impacts of Climate Change on Agricultural Production -- -- -- 22
2.6 Agricultural Adaptation Strategies to climate change -- -- -- 33
2.7 Efficiency -- -- -- -- -- -- -- -- -- 43
2.7.1 Technical Efficiency -- -- -- -- -- -- -- -- 43
2.7.2 Allocative or Price Efficiency -- -- -- -- -- -- 44
2.7.3 Profit Efficiency -- -- -- -- -- -- -- -- 44
2.8 Production Frontier Measures -- -- -- -- -- -- 45
2.9 Stochastic Frontier Analytical Technique of Efficiency Measurement -- 46
2.10 Econometric Approaches for Examining Factors Influencing Efficiency from Stochastic Frontier Analysis -- -- -- 48
2.11 Production Efficiencies and their Determinants: Empirical Evidence -- 49
2.12 Factors Influencing Adoption of Agricultural Technologies and Management Practices -- -- -- -- -- -- -- 56
2.13 Theoretical Framework -- -- -- -- -- -- 62
2.14 Analytical Framework -- -- -- -- -- -- -- 64
3.1 The Study Area -- -- -- -- -- -- -- -- 77
3.2 Sampling Technique -- -- -- -- -- -- -- 78
3.3 Data Collection -- -- -- -- -- -- -- -- 79
3.4 Data Analysis -- -- -- -- -- -- -- -- 80
3.4.1 Likert-Type Rating technique -- -- -- -- -- -- -- 80
3.4.2 Multivariate Discreet Choice Model -- -- -- -- -- -- 81
3.4.3 Stochastic Frontiers Model -- -- -- - -- -- -- 84
126.96.36.199 Stochastic Frontier Production Function -- --- -- -- -- 84
188.8.131.52Stochastic Frontier Profit Function -- -- -- -- -- -- 86
3.4.4 Factor Analysis Model -- -- -- -- -- -- -- 89
4.0 RESULTS AND DISCUSSION
4.1 Socio-economic characteristics of food crop farmers -- -- -- -- 91
4.2 Farming systems practiced by the respondents -- -- -- -- 96
4.3 Climate change adaptation strategies used by food crop farmers -- -- 98
4.4 Perception and awareness of climate change by the respondents -- -- -- 101
4.5 Factors that influence the choice of climate change adaptation strategies used by food crop farmers in Southwestern Nigeria -- -- -- -- 103
4.6 Estimates for parameter estimates of stochastic average production and Cobb-Douglas models – --- -- -- -- -- -- -- 118
4.7 Technical efficiency estimates for food crop farmers in southwestern Nigeria -- -- -- -- -- -- -- -- -- -- 123
4.8 The influence of climate change adaptation strategies on technical efficiency of food crop farmers in southwestern Nigeria -- -- -- -- 125
4.9 Estimates for parameter estimates of stochastic average profit and Cobb-Douglas models -- -- -- -- -- -- -- 129
4.10 Profit efficiency estimates for food crop farmers in Southwestern Nigeria -- -- -- -- -- -- -- -- -- -- 134
4.11 The influence of climate change adaptation strategies on profit efficiency of food crop farmers in Southwestern Nigeria -- -- -- -- 136
4.12 Simulation of selected climate change adaptation strategies -- -- -- 141
4.13 Constraints to climate change adaptation by food crop farmers in Southwestern Nigeria -- -- -- -- -- -- -- -- 143
4.14 Constraints to climate change adaptation by food crop farmers in the savanna agro-ecological zone of southwestern Nigeria -- -- -- -- 146
4.15Constraints to climate change adaptation by food crop farmers in the rainforest agro-ecological zone of southwestern Nigeria------151
5.0 SUMMARY, CONCLUSION, AND RECOMMENDATIONS
5.1 Summary -- -- -- -- -- -- -- -- -- 155
5.2 Conclusion -- -- -- -- -- -- -- -- -- 160
5.3 Recommendations -- -- -- -- -- -- -- -- 161
Major contributions to knowledge -- -- -- -- -- -- 162
Areas of further research -- -- -- -- -- -- 162
REFERENCES -- -- -- -- -- -- -- -- -- 164
1.1 Background of the Study
The process of producing food requires resources, which could be natural or man-made resources. Natural resources include all the materials and forces that are supplied by nature. Those that are most essential for food crop production are land, water, sunshine, air, temperature and soil conditions. Man-made resources (include labour, capital or entrepreneurship) are supplied and influenced by man (Olayide & Heady, 1982; Oyekale, Bolaji & Olowa, 2009). Among the natural resources, climate is the predominant factor that influences food crop production. Climate as defined by Oyekale et al. (2009) is the state of atmosphere, which is created by weather events over a period of time. A slight change in the climate will affect agriculture.
According to Intergovernmental Panel on Climate Change (IPCC) report, the United Nations Framework Convention on Climate Change (UNFCCC) defines climate change as a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global and/or regional atmosphere and which is in addition to natural climate variability observed over comparable time periods (IPCC, 2001). It is obvious from this definition that change is an inherent attribute of climate, which is caused by both human activities (anthropogenic) and natural processes (biogeographical) (Odjugo, 2007, 2009). Climate change is already affecting people, their livelihoods and ecosystems and presents a great development challenge for the global community in general and for the poor people in developing countries in particular (Khanal, 2009). This also presents major challenges to scientists and policy makers.
Literature have shown that for the past decades, anthropogenic factors like urbanization, deforestation, population explosion, industrialization and the release of green house gases (GHGs) are the major contributing factors to the depletion of the ozone layer and its associated global warming and climate change (Buba, 2004; Nigerian Environmental Study/ Action Team [NEST], 2003; Odjugo, 2007). For example, unsustainable industrialization, which releases green house gases (GHGs), is viewed as the main cause (Odjugo, 2009). The level of greenhouse gases (GHGs) mainly Carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) have been rapidly increasing after industrial revolution. The increased level of GHGs has created a greenhouse effect which subsequently altered precipitation patterns and global temperatures around the world. Impacts have been witnessed in several areas due to change in precipitation and temperature. The areas affected include agriculture, forestry, water resources, biodiversity, desertification, human health, and ecosystems goods and services globally (Khanal, 2009; Rosegrant et al.,2008).
Between 1960 and 1998 a decline in mean annual precipitation of between 20% and 40% has been noted in West Africa compared to a 2% to 4% decline in tropical rain forest regions (IPCC, 2007). It is also important to note that rural people and agricultural production in Africa rely on rainfall for water supply with as little as less than 4% of cultivated land under irrigation (Inter Academy Council [IAC], 2004; World Bank, 2008). The predominance of rain-fed agriculture, the scarcity of capital for adaptation measures, their warmer baseline climates and their heightened exposure to extreme events (Nnamchi & Ozor, 2009) reportedly in Africa agriculture to be more vulnerable to climate change. Food crop is particularly sensitive to climate change because crop yields depend largely on prevailing climate conditions (temperature and rainfall patterns) (Palatnik & Roson, 2009), Southwestern Nigeria is not exempted. The principal food crops grown in Southwestern Nigeria are cassava, yams, maize, and cocoyams, which are also sensitive to climate variability and climate change. Subsistence crop production in Southwestern Nigeria is traditional and rain-fed, with very limited areas under irrigation. Small-scale traditional irrigation has been practiced for decades in the area, where small streams are diverted seasonally for limited dry season cropping. Medium and large-scale schemes are very few.
Clear impacts from climate change are being witnessed in agriculture. Impacts are both positive as well as negative. They are dependent on latitude, altitude and type of crop. There have been noticeable impacts on plant production, insect, disease and weed dynamics, soil properties and microbial compositions in farming systems (Khanal, 2009; Rosegrant et al., 2008). Intergovernmental Panel on Climate Change (IPCC) in her synthesis Report on climate change explained how hard it is to find evidence of negative consequences of climate on the world agricultural productivity in aggregate agricultural statistics. One reason is the positive gains from global warming observed in the temperate regions due to reduced risk of frost and longer growing season. The other important reason is that the world agriculture in general but particularly temperate regions had witnessed noticeable increases in productivity of most crops as a result of major technological advances (breeding and improved fertility and pest and diseases management) (IPCC, 2007).
Although there is some evidence that agriculture in temperate regions of the world has benefitted in some ways from global warming the same report states with high confidence that “agricultural production and food security, including access to food, in many African countries and regions are likely to be severely affected by climate change and climate vulnerability”. This is because African economies and the livelihoods of its population are highly dependent on agriculture which is mainly practiced in already harsh climatic condition (e.g. high temperature, marginal environment, and considerable water stress) (IPCC, 2007a). About 60% of the Nigeria population is employed in agricultural sector (National Bureau of Statistics [NBS], 2011).
Nigerian agriculture is already under significant pressure to meet the demand of rising population using finite, often degraded soil and water resources, which are now further stressed by the impact of climate change (Awotoye & Mathew, 2010). As a result, it is of interest to stakeholders in the agricultural sector to understand the kind of impact climate change will have on food and crop production. There will undoubtedly be shifts in agro-ecological conditions that will warrant changes in processes and practices in order to meet daily food requirements. In addition, climate change could become a significant constraint on economic development in developing countries that rely on agriculture for a substantial share of gross domestic production and employment (Rosegrant et al., 2008).
The agro-ecological zones across the Southwestern Nigeria are guinea savanna, derived savanna, freshwater swamp forest, lowland rainforest, and mangrove forest and coastal land (Fasola, 2007). Some changes in agricultural practices might also be taking place across the agro-ecologies of the zone, in order to ensure food security in southwestern Nigeria, a region that feeds about 45 per cent of the nation’s population (Awotoye & Mathew, 2010). Climate change is another challenge to the initial inability of food production to meet up with the demand which is already identified in Nigeria.
Impacts of climate change on the socio-economic sector are projected to include; decline in yield and production, reduced marginal GDP from agriculture, fluctuation in world market price, change in geographical distribution of trade regimes, increased number of people at risk of hunger and food security and migration and civil unrest (Khanal,2009). Increase in temperature, at the same time, might affect both the physical and chemical properties in the soil. Increased temperature may accelerate the rate of releasing CO2 resulting in less than optimal conditions for plant growth. When temperatures exceed the optimal level for biological processes, crop often respond negatively with a steep drop in net growth and yield. Heat stress might affect the whole physiological development, maturation and finally yield of cultivated crops (Khanal, 2009; Rosegrant et al., 2008). Steps must be taken to reduce the negative effects of climate change on Nigeria agriculture, especially food crop production in Southwestern Nigeria.
There are two central ideas for dealing with climate change, namely, mitigation and adaptation. Mitigation is a response strategy to global climate change, and can be explained as measures that reduce the amount of emissions (abatement) or enhance the absorption capacity of greenhouse gases (sequestration). Adaptation to climate change is an adjustment made to human, ecological or physical system in response to vulnerability (Adger et al., 2007). Climate change adaptation through the modification or improvement of agricultural practices will be imperative to continue meeting the growing food demands of modern society (Rosegrant et al., 2008).
The climate is changing and mitigation efforts to reduce sources or enhance the sinks of greenhouse gases will take time. Adaptation is therefore critical and of concern in developing countries, particularly Africa (including Nigeria) where vulnerability is high because the ability to adapt is low. Climate change is expected to affect food and water resources critical to livelihood in Africa and much of the population, especially the poor, rely on local supply systems that are sensitive to climate variations. Disruptions of the existing food and water systems will have devastating implications for development and livelihoods and are expected to add to the challenge already posed by climate change for poverty eradication (De Wit & Stankiewcz, 2006; International Institute of Sustainable Development [IISD], 2007). Adaptation helps farmers achieve their food, income and livelihood security objectives in the face of changing climatic and socioeconomic conditions, including volatile short-term changes in local and large-scale markets (Kandlinkar & Risbey, 2000). Farmers especially food crop farmers can reduce the potential damage by making tactical responses to these changes. Jagtap (1995) identified crop diversification, mixed cropping, using different crop varieties, changing planting and harvesting dates, drought resistant varieties, while Enete et al. (2011) also identified multiple/intercropping, agro-forestry/afforestation, mulching, purchase/harvest of water for irrigation, among others as some of the climate change adaptation strategies in Southeastern Nigeria. Analyzing adaptation strategies is therefore important for finding ways to help food crop farmers adapt in the rural economies of Africa including Nigeria in general and Southwestern Nigeria in particular. There is also evidence of changes in agronomic and management practices in order to cope with climate change and variability across the agro-ecologies in the southwestern Nigeria (Adebayo et al., 2011).
Constant evolution of crop patterns, farm management practices and land use occur across the globe, partly in response to climatic variation. Such farm-level adaptations aim at increasing the productivity, improving efficiency and dealing with existing climatic conditions, and draw farmers’ current knowledge and experience (Commission of the European Communities [CEC], 2009). Although African farmers have a low capacity to adapt to changes, they have, however, survived and coped in various ways over time. Better understanding of how they have done this is essential for designing incentives to enhance private adaptation. Supporting the coping strategies of local farmers through appropriate public policy and investment and collective actions can help increase the adoption of adaptation measures that will reduce the negative consequences of predicted changes in future climate, with great benefits to vulnerable rural communities in Africa (Hassan & Nhemachena, 2008), especially food crop farmers in Southwestern Nigeria. Deressa (2008) posited that farmers adapt to climate change to maximize profit by changing crop mix, planting and harvesting dates, and a host of agronomic practices. The coping strategies adopted by food crop farmers, which are mainly initiated at the farm and village-level in the southwestern Nigeria, are expected to enhance their farm productivities, efficiency and improve their profit as a producing unit.
The ability of farms to employ the “best practice” in the production process so that not more than the necessary amount of a given set of inputs is used in producing the “best” level of output is referred to as technical efficiency (Timmer, 1980). But profit efficiency as defined by Abdulai and Huffman (2000) is the ability of a firm to achieve potential maximum profit, given the level of fixed factors and prices faced by the firm. This study will then want to know how climate change adaptation strategies influence technical and profit inefficiencies of farmers in food crop production in Southwestern Nigeria when linked with related socio-economic variables. The study will go further to simulate some of these variables at various percentages to know their effects on technical and profit inefficiencies in food crop production and see how these can help in policy formulation on climate change adaptation strategies vis-à-vis food crop production efficiency in Nigeria in general and the southwestern part of the country in particular.
1.2 Statement of the Problem
Food production in Nigeria has not kept pace with its population growth, because the population is growing at about 3.2 per cent per annum while food production is at about 2.0 per cent (NBS, 2011). In a bid to address the differentials in the food production and population growth rates, successive governments in Nigeria have come up with policies and programmes. Among them are; National Fadama Development Programme, Root and Tuber Expansion Programme (RTEP), and National Programme for Food Security (NPFS). These policies and programmes were aimed at raising the productivity and the efficiency of agricultural sector. Farmers face challenges of tragic crop failures, reduced agricultural productivity, increased hunger, malnutrition and diseases (Zoellick, 2009).The declining agricultural productivity in Nigeria is worrisome and a real challenge for Government with a population of approximately 150 million people to feed.
Climate change affects agriculture in several ways, one of which is its direct impact on food production. It brings additional perspective to the national challenge of increasing agricultural production to keep pace with the rising population while keeping high standards of environmental protection. Negative effects on agricultural yields will be exacerbated by more frequent extreme weather events (CEC, 2009).
Adaptation reduces the negative impact of climate change (Adger et al., 2003; Kurukulasuriya & Mendelson, 2006a). Adaptation of agronomic techniques and farm strategies is already happening (CEC, 2009). The modification of agricultural practices and production in order to cope with climate change will be imperative in order to meet and continue meeting the growing food demands of Nigerians. Evidence shows that farming systems and farming technologies within the region have been changing in response to the effects of climate change (Adebayo et al., 2011). In their study conducted in Southwest Nigeria, Adebayo et al. (2011) showed that the farmers agreed that the main climate change effect is on reduction of their personal productivity. Adapting to climate change and climate variability at the farm-level by the farmers especially through the modification of agricultural practices and farming systems has been recognized as the main coping strategies. It is believed that these strategies are supposed to help the farmers improve their personal productivity and efficiency in food crop production and also raise their returns to farming as a business.
Previous studies (Ajibefun, 2006; Ajibefun, Batesse & Daramola, 2002; Ajibefun, Daramola & Falusi, 2006; Ogundari, 2006; Otitoju, 2008; Otitoju & Arene, 2010) conducted on efficiency (technical and profit) of farmers only used socioeconomic, farmers’ and farm-specific characteristics to determine the efficiency level of their production. Some other climate-related studies, also in Africa, have analyzed factors affecting the perception and adaptations to climate change (Deressa, 2007; Hassan, 2008; Kurukulasuriya & Mendelsohn, 2006b; Nzeadibe, Egbule, Chukwuone & Agu, 2011), few available climate-related studies (Enete et al., 2011; Nzeh & Eboh, 2011; Onyeneke & Madukwe, 2010) examined adaptation in other parts of Nigeria, only the studies of Adebayo et al. (2011) examined climate change in southwestern Nigeria; Oyekale et al. (2009) also examined the effects of climate change on cocoa production in Ondo state, Nigeria. Awotoye and Matthew (2010) also examined effects of temporal changes in climate variables on crop production in tropical sub-humid southwestern, Nigeria. However, none of these studies looked at the influence of climate change adaptation strategies on food crop production efficiency in the southwestern Nigeria. There is paucity of information on the influence of climate change adaptation strategies on efficiency of food crop farmers in Nigeria especially in the Southwest region of the country. Hence, this study attempts to look at the effects of climate change adaptation strategies on food crop production efficiency (technical and profit) in the southwestern Nigeria to fill these existing knowledge gaps.
1.3 Objectives of the Study
The broad objective of this study is to examine the influence of climate change adaptation strategies on efficiency in food crop production in Southwestern Nigeria. The specific objectives are to:
(i). describe the socio-economic characteristics of farmers and farming systems in food crop production in the study area;
(ii). identify climate change adaptation strategies used by food crop farmers in the study area;
(iii). identify factors that influence the choice of climate change adaptation strategies used by food crop farmers;
(iv). estimate technical and profit efficiencies in food crop production in the study area;
(v). determine the influence of climate change adaptation strategies used by the farmers on food crop production efficiency in the study area;
(vi). assess the variations in levels of technical efficiency in food crop production as a result of simulated changes in selected climate change adaptation strategies that could be influenced by policy;
(vii). identify constraints to climate change adaptation by the respondents in the study area;
(viii). make recommendations for improving food crop production efficiency vis-à-vis the climate change.
1.4 Hypotheses of the study
The following null hypotheses were tested:
(i). socioeconomic factors do not influence use of climate change adaptation strategies by food crop farmers;
(ii). institutional and farm-specific variables do not influence use of climate change adaptation strategies by food crop farmers;
(iii). climate change adaptation strategies do not influence technical efficiency in food crop production in the study area; and
(iv). climate change adaptation strategies do not influence profit efficiency of food crop farmers in the study area.
1.5 Justification of the Study
The present inability of food crop production sector to meet the foods demand of Nigerians and the challenge posed by climate change and variability emphasized the need for the improvement of food crop farmers.
Failure to know the present food crop production efficiency (technical and profit) and the influence of climate change coping strategies on efficiency level of food crop production will inhibit designing and formulating appropriate policies to meet food crop production demands of the country. Developing economies can benefit much from inefficiency studies especially a type like this that incorporates farmers’ adaptation strategies to climate change to explain efficiencies.
The results of this study are expected to give direction for policy makers in designing appropriate public policies to increase agricultural productivity and mitigating effects of climate change on food crop production in Nigeria especially in the Southwestern zone. It will provide a useful guide to international and local donor agencies interested in climate change mitigation and adaptation in their provision of grants and funds for environmental and resource management studies. The results of this study will also help agricultural planners in the Agricultural Development Programmes (ADPs) and Ministries of Agriculture, Science and Technology; and Environment in the southwestern region and Nigeria as a whole and those states in the zone with Agro-climatological and Ecological zone study Units in their planning activities and providing useful weather data that will guide in planning public (or planned) adaptations to complement the farm-level (or autonomous) adaptation strategies.
Researchers are going to have a good resource base to look at climate change for further work. Farmers are also going to benefit by knowing those adaptation strategies to climate change that are more productive and efficiency-enhancing.
1.6 Limitations of the Study
The major limitation was on data collection. The enumerators elicited information from the respondents using interview schedule as against the supposed structured questionnaire. The respondents were interviewed all through because of the importance of the information the questionnaire to elicit. It was not self-administered as it is supposed of questionnaire but rather enumerator and researcher-administered (Eboh, 1998). This made the collection of data to take more time than necessary but the data were free of error due to omission of relevant information needed for the study.
Another limitation was the issue of finance for the data collection. This was overcome as the researcher sought for money to address this issue in order to still meet up with the set time for the data collection..