Browsing by Subject "Afrika"

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Governance of emerging biomass-based value webs in Africa : case studies from Ghana
(2018) Poku, Adu-Gyamfi; Birner, Regina
Rising global demand for food as well as for feed and biomass-based raw materials such as fuel and fibre crops has increased pressure on the agricultural sector, especially in Sub-Saharan Africa. The expected trend of increased demand for more diverse biomass-based produce from agricultural land effectively transforms the agriculture sector from just a food-supplying to a biomass-supplying sector in the growing international bioeconomy. This transition is leading to the development of biomass-based value webs whereby there are complex systems of interlinked value chains in which food, fodder, fuels, and other raw materials are produced, processed, traded and consumed. Against this background, this thesis aims to evaluate the appropriate roles of the public, private and third (civil society) sectors in facilitating the transformation of the agricultural sector in the developing bioeconomy in Ghana. The study focuses on the emerging value webs of cassava (Manihot esculenta) and maize (Zea mays), which are the two most important staple crops in Ghana.
Nutritional and hemoglobin status in relation to dietary micronutrient intake: studies in female and male small-scale farmers from Lindi region, Tanzania, and Gurué district, Mozambique
(2024) Eleraky, Laila; Frank, Jan
Inadequate consumption of micronutrient-dense and protein-rich foods, such as vegetables, legumes and meat, are important contributing causes for malnutrition, anemia and micronutrient deficiencies in rural communities of Tanzania and Mozambique. The increasing public health concern of the malnutrition form of overweight has repeatedly been reported in urban as well as rural areas of Sub-Sahara Africa and may have already reached farmers in Tanzania and Mozambique. Nutritional status is assessed by anthropometry, dietary intake and hemoglobin. Compared to the often-used body mass index (BMI) and traditional 24-hour recall, the mid-upper-arm-circumference (MUAC), as well as a food group-based algorithm (CIMI) can be suitable additional assessment tools, especially in resource poor environments. Cross-sectional studies within the framework of the Vegi-Leg project were conducted to assess the nutritional status (anthropometrics and hemoglobin measurements), and the dietary behaviours (Household Dietary Diversity Scores (HDDS), Food Frequency Questionnaires (FFQ) and 24-hour recalls) of female and male farmers from rural areas of Tanzania and Mozambique. Data were analysed by region, sex, age, partly season (Tanzania)and correlates. Additional data from similar projects, namely Scale-N and Trans-SEC in rural villages of Tanzania were included in MUAC and CIMI analysis. MUAC as an additional and easy-to-handle anthropometric marker for underweight, as well as overweight was evaluated using data from Vegi-Leg and Scale-N surveys. MUAC cut-offs, calculated via BMI cut-offs and multiple linear regression (MLR), compared to those selected by highest Youden’s index (YI) value, were assessed. The CIMI algorithm included 23 food groups and was tested in comparison to NutriSurvey (detailed quantitative 24 hour recalls) with data from Scale-N and Trans-SEC.A total of 1526 farmers from the Vegi-Leg project (669 from Tanzania, 857 from Mozambique) were studied, of whom 19% were overweight and 35% were anemic. The study showed an overall higher prevalence of overweight (19%) than underweight (10%), mainly due to the high prevalence of overweight female farmers (up to 35%) in southern Tanzania. The highest prevalence of overweight and anemia, at 35% and 48%, was observed in Tanzanian and Mozambican women, respectively. Regarding HDDS and FFQ data, pigeon pea farmers in Lindi and Gurué reported high consumption frequencies of cereals, legumes, vegetables and oil, while meat, fish and eggs were only consumed rarely. Overall, only a small proportion of enrolled women and men reached the recommended daily dietary intake of vitamin A (10%), iron (51%) and zinc (44%) according to the 24-hour recalls. Multiple regression models revealed that dark green leafy vegetables (DGLVs) highly predicted vitamin A intake, whereas legumes in Tanzania and starchy plants in Mozambique were the dominant sources of vitamin A. Cereals contributed to over half of the iron and the zinc intake in both countries. Seasonal analysis revealed high fluctuations for the consumption frequency of food items from the food groups ‘legumes and pulses’, ‘green leafy vegetables’, ‘other vegetables’ and ‘fruits’, including tomatoes, pigeon peas, mangoes and oranges. The results from Lindi Tanzania revealed, that in seasons, when the availability of food groups like fruits, legumes or vegetables was low, the consumption frequency decreased significantly. BMI, which correlated positively and strongly with MUAC, was higher in Tanzania than in Mozambique and higher among female than male farmers, and decreased significantly from the age of 65 years. MUAC cut-offs of <24 cm and ≥30.5 cm, calculated by multiple linear regression, detected 55% of farmers being underweight and 74% being overweight, with a specificity of 96%; the higher cut-off <25 cm and lower cut-off ≥29 cm, each selected according to Youden’s Index, consequently detected more underweight (80%) and overweight farmers (91%), but on the basis of a lower specificity (87–88%). The results of the algorithm CIMI and NutriSurvey were similar with regard to the average intake and range of data distribution. The correlation coefficients of NutriSurvey and CIMI with regards to energy (0.931), protein (0.898), iron (0.775) and zinc (0.838) intake, supported the matching of both calculations. An increased consumption of micronutrient rich DGLVs and legumes, while reducing the high amounts of refined sugar, maize and polished rice, is suggested to counteract the high prevalence of anemia and overweight among smallholder farmers in rural Tanzania and Mozambique. MUAC cut-offs to detect malnutrition whether defined via linear regression or Youden’s Index, proved to be easy-to-use tools for large-scale rural screenings of both underweight and overweight. The food group based CIMI algorithm is a valid instrument that calculates energy and nutrient intake in agreement with the preferred nutrition software NutriSurvey.
Optimizing selection efficiency in maize for the drought prone eastern and southern African environments
(2013) Kebede, Aida; Melchinger, Albrecht E.
Breeding for stress tolerance is the most cost effective way of avoiding drought-induced yield reduction in the tropics. Optimizing breeding for drought tolerance at CIMMYT could enhance the effectiveness of this multi-national breeding program and warrant fast delivery of drought tolerant materials to the farmers. Thus, the overall aim of my study was to improve the efficiency of drought tolerance breeding of maize at CIMMYT for the rapid and cost effective advancement of drought tolerant materials for the drought prone regions of the ESA (Eastern and Southern African countries). We screened a diverse source of tropical germplasm for their haploid induction rate (HIR) and the seasonal variation of this trait. We then compared various managed drought and well watered experiments conducted as line per se performance trials (LP) and testcross performance trials (TP) in Kenya and Mexico. Further, we estimated the relative selection efficiency of the principal breeding regions of CIMMYT for the tropics in ESA and Mexico with unselected and selected breeding materials. The specific objectives of my study were to (1) monitor the variation for HIR among diverse source germplasm in tropical maize, (2) determine the relative importance of general (GCA) and specific (SCA) combining abilities of the source germplasm for HIR, (3) investigate the influence of tropical summer and winter seasons and genotype × season interactions on this trait, (4) determine if LP is predictive of TP for yield under drought in sets of lines under development by the CIMMYT maize breeding program in Kenya and Mexico, (5) determine the genetic correlation between performance of lines per se under drought and testcrosses under optimal conditions and assessing its effect on yield potential, (6) examine the correlation between TP under well-watered and drought stress conditions for potential indirect selection efficiency of well-watered conditions in comparison with drought stress, (7) determine the relative importance of regional adaptation of maize hybrids to Mexico and ESA by subdividing the genotype × environment interactions and determining genotypic correlations between both regions, (8) calculate the indirect selection efficiency for selecting materials based on test results from one region on the selection gain in the other region, and (9) identify the most suitable stage for exchanging breeding materials between Mexico and ESA. Source germplasm and induction season affected HIR and MCR (mis-classification rate) considerably in tropical maize. Source germplam with high HIR and low MCR could be used in the initial stage of implementing the DH technology in the tropics. GCA effect was more important than SCA or genotype × season interaction effects for HIR in tropical maize. Thus, enhancing HIR in source germplasm can be achieved through cyclical breeding or recurrent selection. Winter season was considered the best season for induction because it provides suitable environmental conditions for higher HIR and lower MCR. Overall HIR was high enough to apply the in vivo DH technology in the routine breeding activities in tropical maize. There were moderate genotypic correlation and ISE (Indirect Selection Efficiency) values between LP and TP under drought that increased with an increase in stress level. Hence, LP trials were predictive of TP trials particularly under severe drought stress. Furthermore, screening of lines for LP under drought stress did not compromise yield potential. TP under well-watered conditions were not predictive of TP under drought stress emphasizing the need of managed drought trials to identify drought tolerant materials. With the current shift of inbred development to large scale DH line production, LP evaluations can reduce the cost of making large numbers of testcrosses and optimize breeding for drought tolerant hybrids in the tropics. The exchange of breeding materials between ESA and Mexico can be done with early and late generation materials. This is because there was negligible genotype by region interactions as compared to genotype by location interactions within each region and high genotypic correlations between the two regions. Further, ISE estimates for trials conducted in Mexico and in ESA were high. Adaptive diseases for each location might hamper the exchange of materials, however, with current molecular marker tools like marker assisted selection and genomic selection, the problem of selecting for disease resistance in the region where the disease is not prevalent seems promising. In conclusion, there are ample opportunities in the CIMMYT maize breeding program to optimize breeding for drought tolerance in the tropics through rapid and large scale production of DH lines and evaluation of these lines for LP in managed drought trials. Moreover, breeders from ESA and Mexico could benefit from each other?s materials and test results by regular exchange of breeding materials at both the early and late stages of testing.
Perspectives for donkey-drawn mechanization of field work in Southern Niger
(2004) Emhardt, Frank; Kutzbach, Heinz Dieter
Subsistence oriented rainfed farming in the South and extensive cattle pasturage on grassland savannas in the Sahel is the mode for life for 95 % of the people in Niger. The majority of the farmers would adopt animal drawn technology if it is reliable, inexpensive, simple to use, sound and sturdy technology without permanent risk of failure. Within the present thesis it is focused exclusively on donkey traction as a source of farm power for the location specific optimization of common farming practices for most oriented to the Djerma farmers? annual working calendar in South-West Niger. Efforts have concentrated on ridging, sowing, weeding and mulching.
Prediction of soil properties for agricultural and environmental applications from infrared and X-ray soil spectral properties
(2013) Towett, Erick Kibet; Cadisch, Georg
Many of today?s most pressing problems facing developing countries, such as food security, climate change, and environmental protection, require large area data on soil functional capacity. Conventional assessments (methods and measurements) of soil capacity to perform specific agricultural and environmental functions are time consuming and expensive. In addition, repeatability, reproducibility and accuracy of conventional soil analytical data are major challenges. New, rapid methods to quantify soil properties are needed, especially in developing countries where reliable data on soil properties is sparse, and to take advantage of new opportunities for digital soil mapping. Mid infrared diffuse reflectance spectroscopy (MIR) has already shown promise as a rapid analytical tool and there are new opportunities to include other high-throughput techniques, such as total X-ray fluorescence (TXRF), and X-ray diffraction (XRD) spectroscopy. In this study TXRF and XRD were tested in conjunction with IR to provide powerful diagnostic capabilities for the direct prediction of key soil properties for agricultural and environmental applications especially for Sub-Saharan Africa (SSA) soils. Optimal combinations of spectral methods for use in pedotransfer functions for low cost, rapid prediction of chemical and physical properties of African soils as well as prediction models for soil organic carbon and soil fertility properties (soil extractable nutrients, pH and exchangeable acidity) were tested in this study. These state-of-the-art methods for large-area soil health measurement and monitoring will aid in accelerating economic development in developing sub-Saharan Africa countries with regards to climate change, increasing water scarcity and impacts on local and global food security as well as sustainable agricultural production and ecosystem resilience in the tropics. This study has developed and tested a method for the use of TXRF for direct quantification of total element concentrations in soils using a TXRF (S2 PICOFOXTM) spectrometer and demonstrated that TXRF could be used as a rapid screening tool for total element concentrations in soils assuming sufficient calibration measures are followed. The results of the current study have shown that TXRF can provide efficient chemical fingerprinting which could be further tested for inferring soil chemical and physical functional properties which is of interest in the African soil context for agricultural and environmental management at large scale. Further, this thesis has helped to improve understanding of the variation and patterns of element concentration data for 1034 soil samples from 34 stratified randomly-located 100-km2 ?sentinel? sites across SSA and explored the link between variability of soil properties and climate, parent material, vegetation types and land use patterns with the help of Random Forests statistics. Our results of total element concentration were within the range reported globally for soil Cr, Mn, Zn, Ni, V, Sr, and Y and in the high range for Al, Cu, Ta, Pb, and Ga. There were significant variations (P < 0.05) in total element composition within and between the sites for all the elements analysed. In addition, the greatest proportion of total variance and number of significant variance components occurred at the site (55-88%) followed by the cluster nested within site levels (10-40%). Our results also indicated that the strong observed within site as well as between site variations in many elements can serve to diagnose their soil fertility potential. Explorations of the relationships between element composition data and other site factors using ?randomForest? statistics have demonstrated that all site and soil-forming factors have important influence on total elemental concentrations in the soil with the most important variables explaining the main patterns of variation in total element concentrations being cluster, topography, landuse, precipitation and temperature. However, the importance of cluster can be explained by spatial correlation at distances of <1 km. This study has also analysed the potential of combining analyses undertaken using MIR spectroscopy and TXRF on 700 soil samples from 44 ?sentinel? sites distributed across SSA. MIR prediction models for soil organic carbon, and other soil fertility properties (such as soil extractable nutrients, pH, exchangeable acidity and soil texture) were developed using Random Forests (RF) regression and the current study has added total element concentration data to the residuals of the MIRS predictions to test how they can improve the MIR prediction accuracies. The RF approach out-perfomed the conventional partial least squares regression (PLSR) on simultaneous determination of soil properties; and in addition, RF results were also easily interpretable, computationally much faster and did not rely on data transformations or any other assumptions about data distributions compared to PLSR. With respect to the potential of combining TXRF and MIR spectra, including total element concentration data from TXRF analysis in the RF models significantly reduced root mean square error of prediction by 63% for Ecd, 54% for Mehlich-3 S, and 53% for Mehlich-3 Na. Thus, TXRF spectra were a useful supplement to improve prediction of soil properties not well predicted by MIRS. The prediction improvement from including TXRF was due to detection of a few outliers that did not appear as MIR spectral outliers. MIR showed remarkable ability to capture total elemental composition effects on physico-chemical soil properties but TXRF may have potential for outlier detection in large studies. This study has also helped to develop high-throughput spectral analytical methods and provided recommendations on optimal spectral analytical methods for the Globally Integrated Africa Soil Information Service (AfSIS) Project. Successfully developed methods in this study will become part of the standard AfSIS procedures.
Two worlds in agricultural policy making in Africa? Case studies from Ghana, Kenya, Senegal and Uganda
(2016) Mockshell, Jonathan; Birner, Regina
There has been a renewed interest among donors and domestic policy makers in promoting agricultural development in Africa. Such renewed interest is evident in initiatives, such as the Comprehensive Africa Agricultural Development Program (CAADP), the Alliance for a Green Revolution in Africa (AGRA), the New Alliance for Food Security and Nutrition, and TerrAfrica. Yet, the choice of policy instruments that are most suitable to promote agricultural development in Africa remains subject to a contested debate. The main objective of this cumulative thesis is to analyze the role that the policy beliefs of different actors play in determining policy choices and policy implementation, a topic that has been largely neglected in the agricultural economics and political science literature on the political economy of agricultural policies in Africa. While some policy actors argue that agricultural development requires strong state support, others criticize state-focused instruments and favor market-oriented strategies. Examples of such unresolved debates regarding the role of the state versus the private sector include controversies about input subsidies, import taxes, price stabilization, and buffer stock programs. On the ground, one can observe that African governments implement input subsidy programs and reverse the abolishment of parastatal organizations, in spite of the prevailing critique of such policy instruments by some donor organizations. As the literature reviews included in this thesis show, the dominant explanations in the agricultural economics literature for the choice of such agricultural policies have mainly been based on the rational choice paradigm, such as interest group theories and voter-politician models. Explanations in the political science literature have focused on the role of politician’s self- interest in the form of patronage. Neither of these strands of literature has paid attention to the role of policy beliefs that different actors have and the influence of such beliefs on policy choices. The main rationale for this thesis is the proposition that a narrow focus on self-interest in the prevailing explanations of agricultural policy choices in Africa limits their value. This is especially the case, if the goal of policy research is to identify strategies on how long-standing controversies can be resolved with a view to moving towards more effective policy implementation. This thesis is based on case studies conducted in four countries: Ghana, Kenya, Senegal, and Uganda. The countries were selected because they are similar in the following aspects: They are largely agrarian-based, they implemented Structural Adjustment Programs in the 1980s, and they moved towards increasing support to agriculture in recent years. However, they differ in important characteristics, especially regarding the nature of their political system. These characteristics make them good case study examples for analyzing contested agricultural policy debates. By combining different types of case studies, the thesis covers the entire spectrum from policy formulation to policy implementation. The thesis begins with an introduction, which presents the rationale for the study, provides background information on the agricultural policy context in the four case study countries, and reviews the relevant literature in the fields of agricultural economics and political science. After the introduction, the thesis presents two case studies that deal with policy formulation. They focus on the policy discourse in three of the four case study countries, namely, Senegal, Ghana, and Uganda. In these case studies, the roles of policy discourses and policy beliefs in the policy process are examined. The case studies combine the Advocacy Coalition Framework with discourse analysis and narrative policy analysis to identify the predominant policy beliefs of different coalitions of actors. Based on interviews with a wide range of policy-makers and stakeholders, two main coalitions were identified in each country. In the case study of Ghana and Uganda, these coalitions were labeled “donor discourse coalition” and “domestic discourse coalition.” In Senegal, the labels “agricultural support coalition” and “agricultural support critique coalition” were used. As the cluster analysis showed, the donor coalition and the agricultural support critique coalition mostly comprise international financial institutions, the finance ministry, and academia. Members from the agricultural ministry, Parliament, political parties, and civil society groups mostly form the domestic coalition and the agricultural support coalition. The study finds strikingly similar patterns of policy beliefs across the three case study countries. Donors and domestic policy makers held fundamentally different policy beliefs regarding the question: What does it take to develop smallholder agriculture? While domestic policy actors tend to believe that transforming smallholder agriculture requires public intervention to provide modern inputs at subsidized rates, members of the donor coalition tend to believe that these interventions are market distorting and only motivated by political patronage. The narrative policy analysis of the discourses suggests that the agricultural support narrative has a convincing story-line with a clear beginning (low productivity caused by lack of inputs), middle (providing subsidized inputs), and end (increased productivity). In contrast, the agricultural support critique is mostly presented in the form of a non-story (focusing on what should not be done without providing a convincing alternative story-line of what should be done). Moving from policy formulation to decision-making on policy adoption, the third case study examines how divergent policy beliefs are translated into policy programs. The analysis focuses on two major agricultural programs in Ghana: the Block Farms Program and the agricultural investment program developed under CAADP, called Medium Term Agriculture Sector Investment Plan (METASIP). A participatory mapping of the process leading to the policy programs (called Process Net-Map) was combined with in-depth interviews conducted with policy experts. The empirical results reveal two divergent policy processes: (1) The METASIP policy process that involved broad stakeholder consultation, but where donors were considered the most influential policy actors in the process. (2) The policy process leading to the Block Farms Program. In contrast to the METASIP process, donors did not feature as policy actors in this policy process, which was also less consultative. Domestic policy makers, including the ruling political party, Parliament, and the president, played key roles in this policy process. A fundamental difference between the two programs relates to the policy orientation: The Block Farms Program takes a public sector approach, while METASIP stresses private sector participation in agricultural service provision. Thus, this case study indicates that basic differences in policy beliefs between donors and domestic policy makers are translated into different policy programs through parallel policy processes, which are not connected to each other. Therefore, the case study suggests that “two worlds” (donors and domestic policy makers) exist not only with regard to policy beliefs, but also with regard to policy processes and the resulting policy choices. After having covered policy formulation and policy adoption, the last two case studies deal with policy implementation. They focus on animal health services, because this is a policy field where the case study countries had already implemented policy reforms during the structural adjustment period. These reforms largely followed donor prescriptions to reduce government involvement and promote privatization. The two case studies aimed to analyze the effects of these reforms in relation to prevailing policy beliefs regarding the potential positive and negative effects of privatization. Data for the two case studies were collected through surveys of livestock keepers in a marginal livestock production area in the northern region of Ghana and in a high-potential dairy production area in Kenya. Key informant interviews with livestock policy experts were also conducted in Ghana. The analysis showed that the policy reform of liberalization introduced new players into the animal health service delivery systems. A multinomial logit model was applied to determine the factors that influence households’ choice of service providers. In Ghana, a low potential region (semi-arid, remote) was examined, and the analysis revealed that in this region government para-vets were preferred to community animal health workers and private para- vets. This choice was attributed to the relatively low performance of the community animal health workers, resulting from their limited training. In areas with few or no government para-vets, farmers resorted to self-treatment or to selling sick animals for human consumption, which has undesirable health implications. In Kenya, a high-potential area with intensive dairy production was examined. The results expectedly suggest that service delivery was generally better than in Ghana, as a private service provider market had indeed emerged. In this respect, the experience corresponded to the policy beliefs of those policy actors who had pursued this reform. However, the study found that poorer framers in these areas also face challenges in accessing qualified service providers. Thus, the findings indicate that privatization of livestock services had problematic results for farmers in marginal areas, as well as for poor farmers in high-potential areas. These experiences in the liberalization of the livestock sector may be one contributing factor to why domestic policy makers did not change their policy beliefs regarding the need for government intervention in support of smallholder farming. The final two chapters of the thesis discuss the findings of the five case studies in a cross-cutting perspective and derive implications from for policy processes that aim at developing smallholder agriculture in Africa. As the case studies show, the policy beliefs of donors and domestic policy makers are not easily reconciled, especially since there is a tendency among policy actors on both sides to have a positive self-representation and a negative other representation, which can easily lead to “blame games”. What seems rather problematic for bridging the gap between the “two worlds” is the view identified in the donor discourse that domestic policy makers only pursue government-focused programs as a strategy to stay in political power or to create opportunities for corruption. There would be no contradiction in accepting that domestic policy makers genuinely believe in the need for better physical access of smallholders to inputs, while acknowledging that such instruments have political advantages as well. The study suggests that if donors could accept genuine concerns of domestic policy makers, it would be easier to engage in a more productive policy dialogue, such as on how to make input-subsidy programs more effective or how to address service needs of poor livestock keepers. Based on the proposition that a more consensus-oriented approach will ultimately lead to more effective agricultural policies, the study concludes that it is critical to find strategies to promote such a dialogue between donor coalitions and domestic coalitions. Such strategies may aim at engaging policy actors through deliberation, building new coalitions, promoting policy-oriented learning, and involving policy brokers to find new alternative solutions to reach a consensus. Considering the similarities found across the four case study countries, the study also concludes that the findings are relevant for other African countries.
Untersuchungen leistungsspezifischer Kenngrößen der Zugtiernutzung im südlichen Niger
(1991) Betker, Joachim; Kutzbach, Heinz Dieter
Im Niger wie auch in anderen Ländern verlangt die Ernährung einer ständig wachsenden Bevölkerung nachhaltige Produktionssteigerungen im landwirtschaftlichen Bereich. Die Weiterentwicklung der traditionellen Handarbeit durch die Mechanisierung von Feld- und Transportarbeiten ermöglicht durch eine Steigerung der Arbeitsproduktivität diese notwendige Erhöhung der agrarwirtschaftlichen Produktion. Zielsetzung der vorliegenden Arbeit ist es, Ansätze zu einer Optimierung der Zugtiernutzung durch die Ermittlung leistungsspezifischer Kenngrößen aufzuzeigen. Hierfür ist die Anpassung des Leistungsbedarfs der lokal eingesetzten Gerätetypen an das Leistungsvermögen der vorhandenen Zugtiere von besonderer Bedeutung.