Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Tradeoffs around crop residue biomass in smallholder crop-livestock systems - What's next?
    Tittonell, P.A. ; Gérard, B. ; Erenstein, O. - \ 2015
    Agricultural Systems 134 (2015). - ISSN 0308-521X - p. 119 - 128.
    sub-saharan africa - define conservation agriculture - soil fertility management - south-western niger - food-feed crops - ecological intensification - farming systems - impact assessment - appropriate use - 4th principle
    Much has been written on the tradeoffs that smallholder farmers face when having to allocate their biomass resources among competing objectives such as feed, fuel, mulch, compost or the market. This paper summarises yet a new body of evidence from 10 studies on tradeoffs in the allocation of cereal crop residue biomass between soil management and livestock feeding in developing regions, published in the special issue of Agricultural Systems ‘Biomass use tradeoffs in cereal cropping systems: Lessons and implications from the developing world’. The studies cover a diversity of socio-ecological contexts, farming system types and scales of analysis. We reflect on their main findings and methodological progress, and on the new and not-so-new implications of these findings for research and action in the development agenda. We propose stylised graphical models to portray tradeoffs and plausible trajectories towards synergies, in the hope that such generalisations would prevent further efforts to ‘reinvent the wheel’ in the realm of tradeoffs analysis. We advocate an ex-post impact assessment of recent investments in systems research to help focus such research further and clearly define its future role in prioritizing and targeting development interventions.
    Land-based adaptation to global change: what drives soil and water conservation in Western Africa?
    Sietz, D. ; Dijk, H. van - \ 2015
    Global environmental change : human and policy dimensions 33 (2015). - ISSN 0959-3780 - p. 131 - 141.
    factors influencing adoption - sub-saharan africa - burkina-faso - agricultural innovations - farmers perceptions - dryland development - northeast brazil - central plateau - southern mali - cover change
    Conservation of land resources is a promising strategy for sustainable agricultural intensification in order to adapt dryland farming systems to climate, market and other stresses. At a local level, factors that drive the adoption of conservation measures operate and interact in specific ways. Linking our knowledge of the local specifications of these drivers to regional and global patterns of vulnerability can significantly enhance our understanding of land-based adaptation to global change. However, the factors that influence the adoption of conservation practices remain actively debated. Therefore, this study presents a meta-analysis of case studies that investigate the adoption of soil and water conservation measures, as an important approach to resource conservation. Synthesising 63 adoption cases in the drylands of western Africa, this meta-analysis reveals a multitude of factors that drive the adoption of soil and water conservation practices. The drivers differ strongly between particular practices and methods of analysis used in the case studies. Contributing to the broader debate on resource conservation, the findings highlight the adoption of soil and water conservation measures as an emergent property of farming systems. They demonstrate the need to better understand the socio-ecological foundation of adoption and the pathways along which adoption evolves in space and time. This study concludes with methodological principles to advance future research on the factors that drive the adoption of soil and water conservation measures as a pre-requisite of improving land-based adaptation efforts.
    Strategies for improving water use efficiency in livestock feed production in rain-fed systems
    Kebebe, E.G. ; Oosting, S.J. ; Haileslassie, A. ; Duncan, A.J. ; Boer, I.J.M. de - \ 2015
    Animal 9 (2015)05. - ISSN 1751-7311 - p. 908 - 916.
    sub-saharan africa - life-cycle assessment - agriculture - management - ethiopia - adoption - intensification - farmers - trials - straw
    Livestock production is a major consumer of fresh water, and the influence of livestock production on global fresh water resources is increasing because of the growing demand for livestock products. Increasing water use efficiency of livestock production, therefore, can contribute to the overall water use efficiency of agriculture. Previous studies have reported significant variation in livestock water productivity (LWP) within and among farming systems. Underlying causes of this variation in LWP require further investigation. The objective of this paper was to identify the factors that explain the variation in LWP within and among farming systems in Ethiopia. We quantified LWP for various farms in mixed-crop livestock systems and explored the effect of household demographic characteristics and farm assets on LWP using ANOVA and multilevel mixed-effect linear regression. We focused on water used to cultivate feeds on privately owned agricultural lands. There was a difference in LWP among farming systems and wealth categories. Better-off households followed by medium households had the highest LWP, whereas poor households had the lowest LWP. The variation in LWP among wealth categories could be explained by the differences in the ownership of livestock and availability of family labor. Regression results showed that the age of the household head, the size of the livestock holding and availability of family labor affected LWP positively. The results suggest that water use efficiency could be improved by alleviating resource constraints such as access to farm labor and livestock assets, oxen in particular.
    Participatory appraisal of institutional and political constraints and opportunities for innovation to address parasitic weeds in rice
    Schut, M. ; Rodenburg, J. ; Klerkx, L.W.A. ; Hinnou, L.C. ; Kayeke, J. ; Bastiaans, L. - \ 2015
    Crop Protection 74 (2015). - ISSN 0261-2194 - p. 158 - 170.
    fed lowland rice - striga-hermonthica control - raais rapid appraisal - sub-saharan africa - socioeconomic constraints - integrated analysis - pest-management - systems - benin - tanzania
    Parasitic weeds in smallholder rice production systems, of which Striga asiatica, Striga hermonthica and hamphicarpa fistulosa are the main representatives, form an increasing problem for food and income security in sub-Saharan Africa (SSA). The objective of this paper is to identify institutional and political constraints and opportunities for innovation to address parasitic weed problems in rice. Constraints and opportunities for innovation were studied across three nested systems: the parasitic weed control system, the crop protection system, and the agricultural system. Multi-stakeholder workshops, interviews and surveys were held to gather data on key constraints faced by different stakeholder groups across three parasitic weed infested study sites in both Tanzania and Benin. The results demonstrate that in both countries, the majority of institutional and political constraints relate to the functioning of the broader crop protection and agricultural systems and not specifically to parasitic weeds. Although differences were observed between the two countries and the different stakeholder groups, the majority of constraints perceived by the stakeholders were caused by a lack of capabilities and resources and a limited access to credit. Awareness raising of parasitic weed problems among farmers, extension and crop protection officers at the local level, combined with improved input and service supply and enhanced agricultural education and training curricula at the national level, were identified as important elements for improvement. More structural collaboration between key stakeholder groups is expected to contribute to a better recognition of agricultural problems, like that of parasitic weeds in rice, and a more timely identification of feasible solutions.
    Effects of technical interventions on flexibility of farming systems in Burkina Faso: Lessons for the design of innovations in West Africa
    Andrieu, N. ; Descheemaeker, K.K.E. ; Sanou, T. ; Chia, E. - \ 2015
    Agricultural Systems 136 (2015). - ISSN 0308-521X - p. 125 - 137.
    crop-livestock systems - sub-saharan africa - climate-change - smallholder farmers - coping strategies - modeling approach - decision-making - constraints - uncertainty - variability
    African farmers have always been exposed to climatic and economic variability and have developed a range of coping strategies. Such strategies form part of flexible farm management, an ability that may prove very valuable in the face of future climate change and market dynamics. The generally low productivity of African smallholder farming systems is usually addressed by research and development institutions by a variety of solutions for improving farm performance. However, changes to the system may affect the flexibility of farms and thus their ability to cope with variability. We quantified the added value of being flexible and how this flexibility is affected by technical changes, such as composting and cattle fattening recurrently proposed and promoted by research and development institutions and projects. The study was conducted in two villages of the agro-pastoral area of Burkina Faso, where livestock, cereals and cotton are the main farming activities. A whole-farm simulation model was developed based on information gathered during focus group meetings with farmers and detailed individual monitoring of farmers' practices. The model simulates farmers' decision rules governing the management of the cropping and livestock farm components, as well as crop and livestock production and farm gross margin. Using the existing decision rules, current farm performance was simulated by assessing the cereal balance, the fodder balance and the whole farm gross margin. Then, by comparing the mean and the coefficient of variation of these indicators resulting from (a) the existing decision rules (baseline scenario) and (b) a set of less flexible rules (rigid scenario), the added value of flexible management was revealed. The adoption of composting practices allowed a slight increase in gross margin associated with a decrease in its between-year variability in comparison with conventional practices. Cattle fattening only led to a higher gross margin in the years with high rainfall and low input prices when no management practices were used to limit dependence on external input. This kind of technical change thus requires increased management agility by farmers to deal with climatic and economic variability. We conclude that assessing the impact of technical interventions not only in terms of productivity but also in terms of changes in flexibility is useful for a better understanding of potential adoption of technical changes
    From farm scale synergies to village scale trade-offs: Cereal crop residues use in an agro-pastoral system of the Sudanian zone of Burkina Faso
    Andrieu, N. ; Vayssières, J. ; Corbeels, M. ; Blanchard, M. ; Vall, E. ; Tittonell, P.A. - \ 2015
    Agricultural Systems 134 (2015). - ISSN 0308-521X - p. 84 - 96.
    west-african savanna - sub-saharan africa - livestock systems - conservation agriculture - fertility management - phosphorus budget - soil fertility - spatial carbon - nitrogen - flows
    Traditionally, cereal crop harvest residues are communally grazed by the ruminant herds of villagers and transhumant pastoralists in the agro-pastoral systems which predominate in the savannah zone of West Africa. We analysed the impact of the private use of crop residues by individual farmers on crop and livestock productivity at three scales: the field, farm, and village. We collected data in the village of Koumbia, located in the Sudanian region of Burkina Faso. Three types of farmers were identified: resource-poor farmers, predominantly livestock farmers, and resource-rich farmers. The trade-offs between different uses and users of cereal crop residues at the three scales were analysed through field surveys and a simple model of biomass flows. We considered current communal use practices and two alternative scenarios of private cereal crop residue use: (i) for composting (fertility scenario) and (ii) as fodder (fodder scenario). Our analysis of current practices confirmed that farmers left around 80% of cereal crop residues on their fields. Soil fertility for cereal production therefore could be improved through crop residue management at the farm scale. We also found that communal grazing benefited farmers with high numbers of livestock. Maize grain production at the farm scale was improved in both of the simulated scenarios. Yet these scenarios had a negative impact on fodder self-sufficiency at the village scale, and on the N balance of the savannah-derived rangelands. The negative impact was greater in the fertility scenario than the fodder stock scenario. Increasing cereal productivity at the farm scale cannot be achieved without considering the trade-offs involved at the village scale. Changes in practices will require negotiations between the different types of farmers involved. Participatory innovation platforms with discussion support tools like the model presented in our study can facilitate such negotiations.
    Rhamphicarpa fistulosa, a widespread facultative hemi-parasitic weed, threatening rice production in Africa
    Rodenburg, J. ; Morawetz, J.J. ; Bastiaans, L. - \ 2015
    Weed Research 55 (2015). - ISSN 0043-1737 - p. 118 - 131.
    sub-saharan africa - fed lowland rice - phylogenetic-relationships - rhinanthus-minor - scrophulariaceae - vegetation - orobanchaceae - management - haustoria - habitats
    Rhamphicarpa fistulosa is a facultative hemi-parasitic plant of the Orobanchaceae family, adapted to wet soils. Apart from tropical Australia, it is only found in sub-Saharan Africa, where it is considered a minor weed in cereal crops such as rice. Due to this status, the species has received only sporadic attention. Recent field observations and encounters with rice farmers in several African countries showed that R. fistulosa is, however, a more serious and increasing production constraint than previously thought. Results from a systematic literature review and a global herbarium study support this. The species has a broad distribution over Africa (at least 35 countries from Madagascar to Senegal and from Sudan to South Africa) and a wide range in altitude (0–2150 m a.s.l.) and environment (waterlogged swamps to moist free-draining uplands). Rhamphicarpa fistulosa is relatively independent and persistent because of the presumably wide host range, the facultative nature of its parasitism and its prolific seed (estimated 100 000 seeds m-2 under moderate infestation levels). Finally, R. fistulosa causes severe yield losses (average 60%) and high regional annual economic losses (estimated US $175 million), while effective control options are scant and awareness of the species among important R&D stakeholders is almost absent. An integrated approach is advocated to assist the rice sector to reduce current R. fistulosa-inflicted losses and to prevent further spread of the species into new areas.
    Institutions and access to woodfuel commerce in the Democratic Republic of Congo
    Schure, J.M. ; Ingram, V. ; Arts, B.J.M. ; Levang, P. ; Mvula-Mampasi, E. - \ 2015
    Forest Policy and Economics 50 (2015). - ISSN 1389-9341 - p. 53 - 61.
    sub-saharan africa - developing-countries - poverty alleviation - rural livelihoods - value chains - charcoal - forests - policy - conservation - perspectives
    A new generation of woodfuel studies focuses on the political dynamics behind access to the woodfuel trade, providing better insights into patterns of inclusion and exclusion and options for resource management. Institutional mechanisms that govern access are difficult to untangle in the context of informal trade. This paper analyzes institutions and how they regulate access to commercialize woodfuel in two areas in the Democratic Republic of Congo (DRC). A review of empirical data (surveys and interviews) and secondary data on wood energy value chains in the DRC is used to examine the ways that woodfuel institutions affect access to resources and to markets. The main findings are that existing formal mechanisms regulating access to the woodfuel trade are hardly enforced. Informal, socially embedded institutions generally govern access, and the trade is open to less privileged and rural actors. People who benefit from these informal arrangements have many vested interests, and current production patterns are unsustainable and not sufficiently mitigated by these institutions. New strategies are required that promote the positive aspects of informality, while supporting initiatives that contribute to long-term resource sustainability and meet the high levels of urban demand, given the lack of alternative energy sources.
    RAAIS: Rapid Appraisal of Agricultural Innovation Systems (Part I). A diagnostic tool for integrated analysis of complex problems and innovation capacity
    Schut, M. ; Klerkx, L.W.A. ; Rodenburg, J. ; Kayeke, J. ; Hinnou, L.C. ; Raboanarielina, C.M. ; Adegbola, P.Y. ; Ast, A. van; Bastiaans, L. - \ 2015
    Agricultural Systems 132 (2015). - ISSN 0308-521X - p. 1 - 11.
    sub-saharan africa - fed lowland rice - framework - policy - perspective - benin - participation - information - reflection - management
    This paper introduces Rapid Appraisal of Agricultural Innovation Systems (RAAIS). RAAIS is a diagnostic tool that can guide the analysis of complex agricultural problems and innovation capacity of the agricultural system in which the complex agricultural problem is embedded. RAAIS focuses on the integrated analysis of different dimensions of problems (e.g. biophysical, technological, socio-cultural, economic, institutional and political), interactions across different levels (e.g. national, regional, local), and the constraints and interests of different stakeholder groups (farmers, government, researchers, etc.). Innovation capacity in the agricultural system is studied by analysing (1) constraints within the institutional, sectoral and technological subsystems of the agricultural system, and (2) the existence and performance of the agricultural innovation support system. RAAIS combines multiple qualitative and quantitative methods, and insider (stakeholders) and outsider (researchers) analyses which allow for critical triangulation and validation of the gathered data. Such an analysis can provide specific entry points for innovations to address the complex agricultural problem under study, and generic entry points for innovation related to strengthening the innovation capacity of agricultural system and the functioning of the agricultural innovation support system. The application of RAAIS to analyse parasitic weed problems in the rice sector, conducted in Tanzania and Benin, demonstrates the potential of the diagnostic tool and provides recommendations for its further development and use.
    RAAIS: Rapid Appraisal of Agricultural Innovation Systems (Part II). Integrated analysis of parasitic weed problems in rice in Tanzania
    Schut, M. ; Rodenburg, J. ; Klerkx, L.W.A. ; Kayeke, J. ; Ast, A. van; Bastiaans, L. - \ 2015
    Agricultural Systems 132 (2015). - ISSN 0308-521X - p. 12 - 24.
    sub-saharan africa - fed lowland rice - west-africa - management - framework - policy - determinants - networks - science - design
    Parasitic weeds such as Striga spp and Rhamphicarpa fistulosa in smallholder rice production systems form an increasing problem for food and income security in sub-Saharan Africa. In this paper we implement the Rapid Appraisal of Agricultural Innovation Systems (RAAIS) as a diagnostic tool to identify specific and generic entry points for innovations to address parasitic weeds in rain-fed rice production in Tanzania. Data were gathered across three study sites in Tanzania where parasitic weeds are eminent (Kyela, Songea Rural and Morogoro Rural districts). The results demonstrate that in Tanzania, weeds in general and parasitic weeds in particular receive little attention in agricultural research, training and education curricula. Crop protection policies mainly focus on the control of (insect) pest and diseases and there is relatively little attention for weed prevention, which is essential for addressing parasitic weed problems effectively. Specific entry points for innovation include increasing awareness of parasitic weed problems among farmers, extension and crop protection officers and policymakers. In regions where awareness is relatively high, participatory research approaches can provide a basis for developing locally adapted parasitic weed management strategies. Generic entry points for innovation include enhanced collaboration and interaction between stakeholders across different levels, for example in multi-stakeholder platforms. This can provide the basis for developing and implementing coherent policy and development strategies to address structural constraints in the agricultural system, including the promotion of clean local seed systems, investments in physical and knowledge infrastructure development, adequate backstopping of agricultural extension officers, agribusiness training for farmers, quality control of agricultural inputs, timely access to agricultural inputs, and improved access to markets for farmers. Together the specific and generic entry points can strengthen the innovation capacity of Tanzania's agricultural system to address parasitic weed problems, as well as other complex agricultural problems.
    Land tenure in China: Legal, actual and perceived security
    Ma, Xianlei ; Heerink, N. ; Feng, S. ; Shi, X. - \ 2015
    Land Use Policy 42 (2015). - ISSN 0264-8377 - p. 293 - 306.
    agricultural productivity growth - land rental markets - sub-saharan africa - property-rights - investment incentives - technical efficiency - economic-development - housing improvement - social-security - buenos-aires
    This paper examines the magnitudes of legal security, actual security and perceived security of farmland tenure, and the causes of currently prevailing land tenure insecurity in rural China. Two farm household surveys conducted in the northwest of Gansu province in 2010 and in the northeast of Jiangxi province in 2011 are used as case studies. Although recent land tenure reforms have significantly improved legal tenure security, we find that farm households still experience substantial insecurity of actual and perceived land tenure. We argue that social security considerations, ambiguous formulations of laws, and village self-governance rules are three important underlying causes. Actual and perceived land tenure security is lowest in the case study region in Jiangxi province even though the share of off-farm income in rural household incomes is much larger in that region. We explain this finding from investments in land quality improvement made by rural households in the Gansu case study region, the larger per capita land resources in that region, and the limited social security provided by off-farm employment.
    Farm diversity, resource use efficiency and sustainable land management in the western highlands of Kenya
    Mutoko, M.C. ; Hein, L.G. ; Shisanya, C.A. - \ 2014
    Journal of Rural Studies 36 (2014). - ISSN 0743-0167 - p. 108 - 120.
    soil fertility management - sub-saharan africa - technical efficiency - rural poverty - degradation - conservation - agriculture - impact - growth - maize
    Sub-Saharan Africa (SSA) faces further population growth in the coming decades and it is essential to increase food production in rural areas. However, development programs to enhance agricultural productivity have achieved mixed results. This study investigates farm household responses to a changing agro-environment in one of the most densely populated rural districts in SSA and examines practical implications for the promotion of sustainable land management (SLM) practices. The specific objective is to analyze farm diversity and resource use efficiency and their implications for promoting SLM in the highlands of Western Kenya. We carried out an elaborate survey of 236 households, and applied multivariate analysis to analyze farm efficiency and livelihood strategies. We found major differences in responses to a changing agro-environment between five farm types in terms of resource endowment, income strategies and farm practices. Across farm types, efficiency was low indicating poor land productivity. Our study shows that there has been a lack of intensification in land use and that households are increasingly depending on off-farm income. Our findings have a number of implications to programs aiming to promote sustainable land management in SSA. We propose that successful implementation of such programs requires targeting areas highly reliant on agriculture and within these areas focus on households mostly dependent on farming to sustain their welfare. (C) 2014 Elsevier Ltd. All rights reserved.
    Identifying the potential for irrigation development in Mozambique: Capitalizing on the drivers behind farmer-led irrigation expansion
    Beekman, P.W. ; Veldwisch, G.J.A. ; Bolding, J.A. - \ 2014
    Physics and Chemistry of the Earth 76-78 (2014). - ISSN 1474-7065 - p. 54 - 63.
    small private irrigation - sub-saharan africa - smallholder irrigation
    Smallholder irrigation in Central Mozambique predominantly takes place in an informal setting. This renders these smallholders and their activities invisible for policy purposes. Identification efforts of smallholder irrigation as well as the potential for new irrigation development are often the basis for policy setting. But the potential is often approached technocratically: the technical availability of water and land with the assumption that smallholder irrigation is not happening and should be developed. Although more and more effort is done to include social economical aspects into the identification as well, it remains a GIS exercise, based on incomplete data using large pixel sizes, analyzing countries or continents as a whole. This study describes and presents the methodology and the results of an irrigation potential identification exercise carried out in two studies in Central Mozambique. Apart from describing the identification methods used, this study highlights the extent of farmer-led irrigation development, its drivers and the potential for farmer-led smallholder irrigation development. This study demonstrates the prolific nature of smallholder irrigation, arguing for the recognition that smallholder farmers are already developing irrigation and that this should lead to changing the focus of identification efforts towards the drivers behind farmer-led irrigation development. Using these context-specific drivers to define the potential for new irrigation development should result in a better response in policy to both the technical and socio-economical potential of smallholder irrigation development.
    Agroforestry solutions to address climate change and food security challenges in Africa
    Mbow, C. ; Neufeldt, H. ; Noordwijk, M. van; Minang, P.A. ; Kowero, G. ; Luedeling, E. - \ 2014
    Current Opinion in Environmental Sustainability 6 (2014). - ISSN 1877-3435 - p. 61 - 67.
    sub-saharan africa - forest degradation - land degradation - climate-change - west-africa - agriculture - systems - intensification - classification - security
    Trees inside and outside forests contribute to food security in Africa in the face of climate variability and change. They also provide environmental and social benefits as part of farming livelihoods. Varied ecological and socio-economic conditions have given rise to specific forms of agroforestry in different parts of Africa. Policies that institutionally segregate forest from agriculture miss opportunities for synergy at landscape scale. More explicit inclusion of agroforestry and the integration of agriculture and forestry agendas in global initiatives on climate change adaptation and mitigation can increase their effectiveness. We identify research gaps and overarching research questions for the contributions in this special issue that may help shape current opinion in environmental sustainability.
    Africa and the Green Revolution : A Global Historical Perspective
    Frankema, E.H.P. - \ 2014
    NJAS Wageningen Journal of Life Sciences 70-71 (2014). - ISSN 1573-5214 - p. 17 - 24.
    sub-saharan africa - british africa - agriculture - revenue - origins - growth
    Two decades of substantial economic growth in Africa have challenged the deep-seated Afro-pessimism of the 1990s and 2000s and re-invigorated the academic debate on Africa's ability to grow out of poverty in the 21st century. Although the opinions differ widely on how sustainable current African growth trajectories are, there is a widespread consensus that a fundamental agricultural transformation is key to consolidate current and future welfare gains. This study interprets recent signs of agricultural productivity growth from a long term global historical context, arguing that the combination of present-day developments in information and communication technology, transport infrastructure, demographic growth, urbanization and in macro-economic governance form a fundamental break with African history. This break does not offer any guarantees, but it does raise the probability that Africa will complete a green revolution of its own.
    Metropolitan Blueprints of Colonial Taxation? Lessons from Fiscal Capacity Building in British and French Africa, c. 1880-1940
    Frankema, E.H.P. ; Waijenburg, M.F.M. van - \ 2014
    Journal of African History 55 (2014)3. - ISSN 0021-8537 - p. 371 - 400.
    sub-saharan africa - growth - education - colonization - institutions - government - legacies - origins - history - world
    The historical and social science literature is divided about the importance of metropolitan blueprints of colonial rule for the development of colonial states. We exploit historical records of colonial state finances to explore the importance of metropolitan identity on the comparative development of fiscal institutions in British and French Africa. Taxes constituted the financial backbone of the colonial state and were vital to the state building efforts of colonial governments. A quantitative comparative perspective shows that pragmatic responses to varying local conditions can easily be mistaken for specific metropolitan blueprints of colonial governance and that under comparable local circumstances the French and British operated in remarkably similar ways.
    Determinants of parasitic weed infestation in rainfed lowland rice in Benin
    N'cho, A.S. ; Mourits, M.C.M. ; Rodenburg, J. ; Demont, M. ; Oude Lansink, A.G.J.M. - \ 2014
    Agricultural Systems 130 (2014). - ISSN 0308-521X - p. 105 - 115.
    sub-saharan africa - rhamphicarpa-fistulosa - striga-hermonthica - farming systems - management - selection - scrophulariaceae - specification - demand - model
    The parasitic weed Rhamphicarpa fistulosa is threatening rainfed lowland rice production in Benin. The aim of this study was to explore factors (such as biophysical characters of the rice growing environment, farmers’ management practices, and socioeconomic characteristics) that affect the infestation of rainfed lowland rice fields by R. fistulosa and farmers’ ability to cope with the problem. Data were collected from 231 rice plots located in 12 inland valleys infested by Rhamphicarpa in Benin. Data were analyzed using a double hurdle model, which analyses both the likelihood (of occurrence) and the severity of infestation. Results showed that 72% of the surveyed rice plots were infested by R. fistulosa and the average severity was 109 plants m-2. The likelihood of infestation was higher on poorly fertile soils and fields located in the inland-valley bottom, and it decreases through timely use of herbicides and ploughing. Severity of infestation was higher on rice plots cultivated by female-headed households farmers and reduced through management practices such as late sowing, timely application of post-emergence herbicide, three hoe or hand weeding operations, medium-rate fertilizer application and prolonged fallow. Likelihood and severity of infestation were found to be negatively correlated. These findings suggest that farmers can reduce the likelihood and the severity of infestation of their plot as long as they are aware of factors causing the problem given their access to and management capacity of production resources.
    Implementation of The World Starts With Me, a comprehensive rights-based sex education programme in Uganda
    Rijsdijk, L.E. ; Bos, A.E.R. ; Lie, R. ; Leerlooijer, J.N. ; Eiling, E. ; Atema, V. ; Gebhardt, W.A. ; Ruiter, R.A.C. - \ 2014
    Health Education Research 29 (2014)2. - ISSN 0268-1153 - p. 340 - 353.
    south-african schools - sub-saharan africa - secondary-schools - aids education - health-promotion - hiv prevention - hiv/aids - interventions - outcomes - fidelity
    This article presents a process evaluation of the implementation of the sex education programme the World Starts With Me (WSWM) for secondary school students in Uganda. The purpose of this mixed-methods study was to examine factors associated with dose delivered (number of lessons implemented) and fidelity of implementation (implementation according to the manual), as well as to identify the main barriers and facilitators of implementation. Teachers’ confidence in teaching WSWM was negatively associated with dose delivered. Confidence in educating and discussing sexuality issues in class was positively associated with fidelity of implementation, whereas the importance teachers attached to open sex education showed a negative association with fidelity. Main barriers for implementing WSWM were lack of time, unavailability of computers, lack of student manuals and lack of financial support and rewards. Other barriers for successful implementation were related to high turnover of staff and insufficient training and guidance of teachers. Teachers’ beliefs/attitudes towards sexuality of adolescents, condom use and sex education were found to be important socio-cognitive factors intervening with full fidelity of implementation. These findings can be used to improve the intervention implementation and to better plan for large-scale dissemination of school-based sex education programmes in sub-Saharan Africa.
    Functions and limitations of farmer cooperatives as innovation intermediaries: Findings from China
    Yang, H. ; Klerkx, L.W.A. ; Leeuwis, C. - \ 2014
    Agricultural Systems 127 (2014). - ISSN 0308-521X - p. 115 - 125.
    international agricultural-research - sub-saharan africa - technological-change - systems perspective - networks - management - extension - knowledge - support
    This article takes an innovation intermediary perspective to examine farmer cooperative’s (FC) roles in facilitating agricultural innovation and its positioning in the agricultural innovation system (AIS). The article draws experiences from the rapidly emerging FC field in China. Three cases are selected to cross check findings from them and innovation journey analysis is used within each case to understand FCs’ engagement in innovation processes. The findings show that FCs cover a wide range of knowledge intermediation and innovation intermediation functions identified by the literature. FCs recognize the importance to connect technical, social and economic dimensions of farming practice and provide corresponding services to link farmers to relevant actors, like extension agencies, research institutes and supermarkets. Though they mainly work through bilateral relationships as opposed to acting as a systemic intermediary, they could take the role of coordinator in the service system and bridge the gap between the research and policy system and everyday farming practice, especially in the absence of a systemic coordinator. However, their legitimacy as intermediary might be challenged due to the potential conflicts with governments, market actors or their members, and their local position may provide insufficient clout for developing durable relationships with relevant actors.
    Climate-induced yield variability and yield gaps of maize (Zea mays L.) in the Central Rift Valley of Ethiopia
    Kassie, B.T. ; Ittersum, M.K. van; Hengsdijk, H. ; Asseng, S. ; Wolf, J. ; Rotter, R.P. - \ 2014
    Field Crops Research 160 (2014). - ISSN 0378-4290 - p. 41 - 53.
    sub-saharan africa - use systems-analysis - crop growth-models - ecological intensification - fertilizer application - simulation-model - water-uptake - agriculture - adaptation - ceres
    There is a high demand for quantitative information on impacts of climate on crop yields, yield gaps and their variability in Ethiopia, yet, quantitative studies that include an indication of uncertainties in the estimates are rare. A multi-model crop growth simulation approach using the two crop models, i.e. Decision Support System for Agro-Technology (DSSAT) and WOrld FOod STudies (WOFOST) was applied to characterize climate-induced variability and yield gaps of maize. The models were calibrated and evaluated with experimental data from the Central Rift Valley (CRV) in Ethiopia. Subsequently, a simulation experiment was carried out with an early maturing (Melkassa1) and a late maturing (BH540) cultivar using historical weather data (1984-2009) of three locations in the CRV. Yield gaps were computed as differences among simulated water-limited yield, on-farm trial yields and average actual farmers' yields. The simulation experiment revealed that the potential yield (average across three sites and 1984-2009) is 8.2-9.2 and 6.8-7.1 Mg/ha for the late maturing and early maturing cultivars, respectively; ranges indicate mean differences between the two models. The simulated water-limited yield (averaged across three sites and 1984-2009) is 7.2-7.9 Mg/ha for the late maturing and 6.1-6.7 Mg/ha for the early maturing cultivar. The water-limited yield shows high inter-annual variability (CV 36%) and about 60% of this variability in yield is explained by the variation in growing season rainfall. The gap between average farmers yield and simulated water-limited yield ranges from 4.7 to 6.0 Mg/ha. The average farmers' yields were 2.0-2.3 Mg/ha, which is about 1.1-3.1 Mg/ha lower than on-farm trial yields. In relative terms, average farmers' yields are 28-30% of the water-limited yield and 44-65% of on-farm trial yields. Analysis of yield gaps for different number of years to drive average yields indicates that yield gap estimation on the basis of few years may result in misleading conclusions. Approximately ten years of data are required to be able to estimate yield gaps for the Central Rift Valley in a robust manner. Existing yield gaps indicate that there is scope for significantly increasing maize yield in the CRV and other, similar agro-ecological zones in Africa, through improved crop and climate risk management strategies. As crop models differ in detail of describing the complex, dynamic processes of crop growth, water use and soil water balances, the multi-model approach provides information on the uncertainty in simulating crop-climate interactions. (C) 2014 Elsevier B.V. All rights reserved.
    Prevalence of gestational diabetes mellitus in urban and rural Tanzania
    Mwanri, A.W. ; Kinabo, J. ; Ramaiya, K. ; Feskens, E.J.M. - \ 2014
    Diabetes Research and Clinical Practice 103 (2014)1. - ISSN 0168-8227 - p. 71 - 78.
    sub-saharan africa - international association - physical-activity - increasing prevalence - maternal hemoglobin - glucose-tolerance - pregnant-women - population - criteria - health
    Aim - To estimate prevalence of gestational diabetes mellitus (GDM) and associated determinants in urban and rural Tanzania. Methods - A cross-sectional study was conducted from 2011 through 2012 in selected urban and rural communities. Pregnant women (609 urban, 301 rural), who were not previously known to have diabetes, participated during usual ante-natal clinic visits. Capillary blood samples were collected at fasting and 2 h after 75 g glucose load and were measured using HemoCue. Diagnosis of GDM was made using 1999 World Health Organization (WHO) criteria. Results - Women in rural areas were younger (26.6 years) than in urban areas (27.5 years). Mean gestational age, height, and mid-upper arm circumference (MUAC) were similar for the two areas. Overall prevalence of GDM averaged 5.9%, with 8.4% in urban area and 1.0% in rural area. Prevalence of GDM was higher for women who had a previous stillbirth (OR 2.8, 95% CI 1.5–5.4), family history of type 2 diabetes (OR 2.1, 95% CI 1.1–4.2), and MUAC above 28 cm (OR 1.9, 95% CI 1.1–3.3), and lower for women with normal hemoglobin compared with anemia (OR 0.45, 95% CI 0.22–0.93). Conclusions - Prevalence of GDM is higher than expected in urban areas in Tanzania, indicating an increasing population who are at risk for delivery complications and type 2 diabetes in Sub-Saharan Africa.
    Systems approaches to innovation in crop protection. A systematic literature review
    Schut, M. ; Rodenburg, J. ; Klerkx, L.W.A. ; Ast, A. van; Bastiaans, L. - \ 2014
    Crop Protection 56 (2014). - ISSN 0261-2194 - p. 98 - 108.
    integrated pest-management - sub-saharan africa - agricultural innovation - conservation agriculture - weed management - food security - sustainable agriculture - rice intensification - disease management - changing climate
    The objective of this paper is to explore the extent to which systems approaches to innovation are reflected in the crop protection literature and how such approaches are used. A systematic literature review is conducted to study the relation between crop protection and systems approaches to innovation in 107 publications. The analysis of the crop protection literature demonstrates that only a small fraction is systems-oriented as compared to the bulk of publications with a technology-oriented approach. The analysis of agricultural innovations systems literature shows that, although crop protection is addressed, the potential of this systems approach remains largely unexplored for crop protection innovation. A large share of the publications included in this review focus on cropping or farming ‘systems’ while ‘innovation’ often equals the development, transfer, adoption and diffusion of crop protection technologies at farm level. There is relatively little attention for the institutional and political dimensions of crop protection and the interactions between farm, regional and national levels in crop protection systems. The traditional division of roles and responsibilities of researchers as innovators, extension personnel as disseminators, and farmers as end-users, is challenged only to a limited extent. The majority of publications discusses ways to optimise existing features of crop protection systems, without exploring more structural transformations that may be required to enhance the resilience of crop protection systems.
    Assessing the potential of dual-purpose maize in southern Africa: A multi-level approach
    Homann-Kee Tui, S. ; Blümmel, M. ; Valbuena, D.F. ; Chirima, A. ; Maskati, P. ; Rooyen, A.F. van; Kassie, G.T. - \ 2013
    Field Crops Research 153 (2013). - ISSN 0378-4290 - p. 37 - 51.
    crop-livestock systems - net primary production - sub-saharan africa - water productivity - benefits
    This paper explores the potential and challenges of increasing production of food and feed on existing maize fields in mixed crop-livestock systems in the semi-arid areas of southern Africa. It integrates results from different sources of data and analysis: 1. Spatial stratification using secondary data for GIS layers: Maize mega-environments combined with recommendation domains for dual-purpose maize were constructed for Malawi, Mozambique and Zimbabwe, stratifying the countries by demand factors (livestock densities and human population densities) and feed availability. Relative biomass contributions to feed resources from rangelands were compared to those from croplands to explore the usefulness of global datasets for feed supply estimations. 2. Verification through farming systems analysis: the potential demand for maize residues as feed (maize cropping patterns, maize yields and uses, feed deficits) was compared at contrasting sites, based on household survey data collected on 480 households in 2010. 3. Maize cultivar analysis: Genotypic variability of maize cultivars was compared to evaluate the potential contribution (stover quantity and quality) of dual-purpose maize to reduce feed deficits. The study results illustrate high spatial variability in the demand for and supply of maize residues. Northern Malawi is characterized by high livestock density, high human population density and high feed availability. Farmers achieve maize yields of more than 2 t/ha resulting in surplus of residues. Although livestock is important, southwest Zimbabwe has low livestock densities, low human populations and low feed availability; farming systems are more integrated and farmers make greater use of maize residues to address feed shortages. Central Mozambique also has low cattle densities, low human populations and low feed availability. More rangelands are available but maize yields are very low and livestock face severe feed shortages. The investigation of 14 advanced CIMMYT maize landraces cultivars and 15 advanced hybrids revealed significant variations in grain and stover yield and fodder quality traits. Where livestock densities are high and alternative feed resources are insufficient, maize cultivars with superior residue yield and fodder quality can have substantial impact on livestock productivity. Cultivars at the higher end of the quality range can provide sufficient energy for providing livestock maintenance requirements and support about 200 g of live weight gain daily. Maize cultivars can be targeted according to primary constraints of demand domains for either stover quantity or stover fodder quality and the paper proposes an approach for this based on voluntary feed intake estimates for maize stover.
    Adapting to Climate Variability and Change: Experiences from Cereal-Based Farming in the Central Rift and Kobo Valleys, Ethiopia
    Kassie, B.T. ; Hengsdijk, H. ; Rötter, R. ; Kahiluoto, H. ; Asseng, S. ; Ittersum, M.K. van - \ 2013
    Environmental Management 52 (2013)5. - ISSN 0364-152X - p. 1115 - 1131.
    sub-saharan africa - farmer perceptions - northern ethiopia - coping strategies - south-africa - rainfall - adaptation - agriculture - drought - risk
    Small-holder farmers in Ethiopia are facing several climate related hazards, in particular highly variable rainfall with severe droughts which can have devastating effects on their livelihoods. Projected changes in climate are expected to aggravate the existing challenges. This study examines farmer perceptions on current climate variability and long-term changes, current adaptive strategies, and potential barriers for successful further adaptation in two case study regions—the Central Rift Valley (CRV) and Kobo Valley. The study was based on a household questionnaire, interviews with key stakeholders, and focus group discussions. The result revealed that about 99 % of the respondents at the CRV and 96 % at the Kobo Valley perceived an increase in temperature and 94 % at CRV and 91 % at the Kobo Valley perceived a decrease in rainfall over the last 20–30 years. Inter-annual and intraseasonal rainfall variability also has increased according to the farmers. The observed climate data (1977–2009) also showed an increasing trend in temperature and high inter-annual and intra-seasonal rainfall variability. In contrast to farmers’ perceptions of a decrease in rainfall totals, observed rainfall data showed no statistically significant decline. The interaction among various bio-physical and socio-economic factors, changes in rainfall intensity and reduced water available to crops due to increased hot spells, may have influenced the perception of farmers with respect to rainfall trends. In recent decades, farmers in both the CRV and Kobo have changed farming practices to adapt to perceived climate change and variability, for example, through crop and variety choice, adjustment of cropping calendar, and in situ moisture conservation. These relatively low-cost changes in farm practices were within the limited adaptation capacity of farmers, which may be insufficient to deal with the impacts of future climate change. Anticipated climate change is expected to impose new risks outside the range of current experiences. To enable farmers to adapt to these impacts critical technological, institutional, and market-access constraints need to be removed. Inconsistencies between farmers’ perceptions and observed climate trends (e.g., decrease in annual rainfall) could lead to sub-optimal or counterproductive adaptations, and therefore must be removed by better communication and capacity building, for example through Climate Field Schools. Enabling strategies, which are among others targeted at agricultural inputs, credit supply, market access, and strengthening of local knowledge and information services need to become integral part of government policies to assist farmers to adapt to the impacts of current and future climate change.
    Qualitative evaluation of the Teenage Mothers Project in Uganda: a community-based empowerment intervention for unmarried teenage mothers
    Leerlooijer, J.N. ; Bos, A.E.R. ; Ruiter, R.A.C. ; Reeuwijk, M.A.J. van; Rijsdijk, E. ; Nshakira, N. ; Kok, G. - \ 2013
    BMC Public Health 13 (2013). - ISSN 1471-2458 - 15 p.
    intimate-partner violence - sub-saharan africa - hiv prevention - south-africa - health - adolescents - stigma - risk - trends - school
    Background A large proportion of unmarried teenage mothers in Uganda face physical, psychological, and social problems after pregnancy and childbirth, such as obstetric complications, lack of education, and stigmatisation in their communities. The Teenage Mothers Project (TMP) in Eastern Uganda empowers unmarried teenage mothers to cope with the consequences of early pregnancy and motherhood. Since 2000, 1036 unmarried teenage mothers, their parents, and community leaders participated in economic and social empowerment interventions. The present study explored the changes resulting from the TMP as well as factors that either enabled or inhibited these changes. Methods Semi-structured interviews (N¿=¿23) were conducted with former teenage mothers , community leaders, and project implementers, and lifeline histories were obtained from former teenage mothers (N¿=¿9). Quantitative monitoring data regarding demographic and social characteristics of teenage mother participants (N¿=¿1036) were analysed. Results The findings suggest that, overall, the TMP seems to have contributed to the well-being of unmarried teenage mothers and to a supportive social environment. It appears that the project contributed to supportive community norms towards teenage mothers’ position and future opportunities, increased agency, improved coping with early motherhood and stigma, continued education, and increased income generation by teenage mothers. The study findings also suggest limited change in disapproving community norms regarding out-of-wedlock sex and pregnancy, late active enrolment of teenage mothers in the project (i.e., ten months after delivery of the child), and differences in the extent to which parents provided support. Conclusions It is concluded that strengths of the community-based TMP seem to be its socio-ecological approach, the participatory planning with community leaders and other stakeholders, counselling of parents and unmarried teenage mothers, and the emphasis on education and income generation. The project can improve by earlier active participation of unmarried pregnant adolescents and increased support for parents.
    Witchcraft Beliefs and Witch Hunts
    Koning, N.B.J. - \ 2013
    Human Nature-An Interdisciplinary Biosocial Perspective 24 (2013)2. - ISSN 1045-6767 - p. 158 - 181.
    sub-saharan africa - human amygdala - facial expressions - civil-society - voodoo death - politics - dynamics - wealth - fear - cooperation
    This paper proposes an interdisciplinary explanation of the cross-cultural similarities and evolutionary patterns of witchcraft beliefs. It argues that human social dilemmas have led to the evolution of a fear system that is sensitive to signs of deceit and envy. This was adapted in the evolutionary environment of small foraging bands but became overstimulated by the consequences of the Agricultural Revolution, leading to witch paranoia. State formation, civilization, and economic development abated the fear of witches and replaced it in part with more collectivist forms of social paranoia. However, demographic-economic crises could rekindle fear of witches —resulting, for example, in the witch craze of early modern Europe. The Industrial Revolution broke the Malthusian shackles, but modern economic growth requires agricultural development as a starting point. In sub-Saharan Africa, witch paranoia has resurged because the conditions for agricultural development are lacking, leading to fighting for opportunities and an erosion of intergenerational reciprocity
    Nutrient flows and balances in urban and peri-urban agroecosystems of Kano, Nigeria
    Abdulkadir, A. ; Leffelaar, P.A. ; Agbenin, J.O. ; Giller, K.E. - \ 2013
    Nutrient Cycling in Agroecosystems 95 (2013)2. - ISSN 1385-1314 - p. 231 - 254.
    sub-saharan africa - dissolved organic nitrogen - vegetable farming systems - agricultural land-use - northern nigeria - water-quality - waste-water - west-africa - economic-performance - exchange equilibria
    Nutrient balances are useful indicators to assess the sustainability of farming systems. This study study investigates inflow and outflow of major nutrients in urban and periurban production systems in Kano, Nigeria. To this end, 16 households representing three different urban and peri-urban (UPA) farming systems were studied using the MONQI toolbox (formerly known as NUTMON) to calculate nutrient flows and economic performances. The farm nitrogen (N) balance was positive at 56.6, 67.4 and 56.4 kg farm-1 year-1 for commercial garden and crop-livestock (cGCL), commercial gardening and semi-commercial livestock (cGscL) and commercial livestock subsistence field cropping (cLsC) farm types, respectively. The same trend was observed for phosphorus (P) and potassium (K) in all farm types except an annual negative K balance of 16 kg farm-1 in cGCL. Across the different activities within the farms, land uses had positive N (359, 387 and 563 kg N ha-1 year-1) and P (74, 219 and 411 kg P ha-1 year-1) balances for all farm types, but again a negative K balance in cGCL with an average loss of 533 kg K ha-1 year-1. Partial nutrient balances in livestock production indicated a positive balance for all nutrients across the farms types but were slightly negative for P in cLsC. Commercial livestock keeping (cLsC) was economically more profitable than the other farm types with an average annual gross margin (GM) and net cash flow (NCF) of 9,033and 935. Cropping activities within cGCL and cGscL had GMs of 1,059and 194 and NCFs of 757and 206, respectively, but livestock activities in both farm types incurred financial losses. Potassium inputs were limited under vegetable and crop production of cGCL, threatening long-term K nutrient availability in this system. Overall, the results indicated large annual surpluses of N and P in urban and peri-urban vegetable and crop production systems which pose a potential threat when lost to the environment. Appropriate policies should aim at promoting sustainable production through efficient nutrient management in the Kano UPA sector.
    Defining falciparum malaria attributable sever febrile illness in moderate to high transmission settings based on plasma PfHRP2 concentration
    Hendriksen, I.C.E. ; White, L.J. ; Veenemans, J. ; Verhoef, J.C.M. - \ 2013
    The Journal of Infectious Diseases 207 (2013)2. - ISSN 0022-1899 - p. 351 - 361.
    histidine-rich protein-2 - north-eastern tanzania - sub-saharan africa - plasmodium-falciparum - cerebral malaria - case definitions - systematic analysis - clinical-diagnosis - malawian children - endemic areas
    Background. In malaria-endemic settings, asymptomatic parasitemia complicates the diagnosis of malaria. Histidine-rich protein 2 (HRP2) is produced by Plasmodium falciparum, and its plasma concentration reflects the total body parasite burden. We aimed to define the malaria-attributable fraction of severe febrile illness, using the distributions of plasma P. falciparum HRP2 (PfHRP2) concentrations from parasitemic children with different clinical presentations. Methods. Plasma samples were collected from and peripheral blood slides prepared for 1435 children aged 6-60 months in communities and a nearby hospital in northeastern Tanzania. The study population included children with severe or uncomplicated malaria, asymptomatic carriers, and healthy control subjects who had negative results of rapid diagnostic tests. The distributions of plasma PfHRP2 concentrations among the different groups were used to model severe malaria-attributable disease. Results. The plasma PfHRP2 concentration showed a close correlation with the severity of infection. PfHRP2 concentrations of >1000 ng/mL denoted a malaria-attributable fraction of severe disease of 99% (95% credible interval [CI], 96%-100%), with a sensitivity of 74% (95% CI, 72%-77%), whereas a concentration of 10% (95% CI, 3%-27%) of patients. Bacteremia was more common among patients in the lowest and highest PfHRP2 concentration quintiles. Conclusions. The plasma PfHRP2 concentration defines malaria-attributable disease and distinguishes severe malaria from coincidental parasitemia in African children in a moderate-to-high transmission setting.
    Perceptions on reducing constraints for smalholder entrepreneurship in Africa: the case of soil fertility in Northern Ghana
    Becx, G.A. ; Mol, G. ; Eenhoorn, J.W. ; Kamp, J. van der; Vliet, J.M. van - \ 2012
    Current Opinion in Environmental Sustainability 4 (2012)5. - ISSN 1877-3435 - p. 489 - 496.
    sub-saharan africa - west-africa - management
    Effective poverty reduction in Africa requires enabling more smallholder farmers to move from subsistence farming to a more entrepreneurial fashion of farming. Earlier studies showed that smallholders are constrained in doing so because of lack of incentives, high risks, production problems and lack of an entrepreneurial mindset. Deterioration and improvement of the natural resource base impact these constraints. In this paper we not only focus on soil fertility decline and the available measures to combat this decline but also on the reasons smallholders have for applying them or not. 94% of the 232 smallholders we interviewed in this study report a decline of their soil fertility. During interviews smallholders in northern Ghana gave their reasons for (not) applying the soil fertility enhancing measures manure use, use of household waste, compost making, use of mineral fertilizer, fallowing, improved fallow, use of cover crops, use of human excreta, crop rotation, anti-erosion measures, and non-burning practices. In this paper we evaluate the constraints of implementation of the different soil improvement measures. The most striking conclusion is that implementation of these measures is restricted by the same constraints context that restricts smallholder entrepreneurship in the first place. We therefore argue that, to develop subsistence farmers into more entrepreneurial farmers, support programs are needed that address the entire constraints context for smallholder farmers.
    Correlates of Delayed Sexual Intercourse and Condom Use among Adolescents in Uganda: a cross-sectional study
    Rijsdijk, L.E. ; Bos, A.E.R. ; Lie, R. ; Ruiter, R.A.C. ; Leerlooijer, J.N. ; Kok, G. - \ 2012
    BMC Public Health 12 (2012). - ISSN 1471-2458 - 19 p.
    sub-saharan africa - planned behavior - south-africa - reproductive health - university-students - multilevel analysis - reasoned action - determinants - youth - risk
    Background - Comprehensive sex education, including the promotion of consistent condom use, is still an important intervention strategy in tackling unplanned pregnancies, HIV/AIDS and sexually transmitted infections (STIs) among Ugandan adolescents. This study examines predictors of the intention to use a condom and the intention to delay sexual intercourse among secondary school students (aged 12–20) in Uganda. Methods - A school-based sample was drawn from 48 secondary schools throughout Uganda. Participants (N¿=¿1978) completed a survey in English measuring beliefs regarding pregnancy, STIs and HIV and AIDS, attitudes, social norms and self-efficacy towards condom use and abstinence/delay, intention to use a condom and intention to delay sexual intercourse. As secondary sexual abstinence is one of the recommended ways for preventing HIV, STIs and unplanned pregnancies among the sexually experienced, participants with and without previous sexual experience were compared. Results - For adolescents without sexual experience (virgins), self-efficacy, perceived social norms and attitude towards condom use predicted the intention to use condoms. Among those with sexual experience (non-virgins), only perceived social norm was a significant predictor. The intention to delay sexual intercourse was, however, predicted similarly for both groups, with attitudes, perceived social norm and self-efficacy being significant predictors. Conclusions This study has established relevant predictors of intentions of safe sex among young Ugandans and has shown that the intention to use condoms is motivated by different factors depending on previous sexual experience. A segmented approach to intervention development and implementation is thus recommended
    Tailoring conservation agriculture technologies to West Africa semi-arid zones: Building on traditional local practices for soil restoration
    Lahmar, R. ; Bationo, B.A. ; Lamso, N.D. ; Guéro, Y. ; Tittonell, P.A. - \ 2012
    Field Crops Research 132 (2012). - ISSN 0378-4290 - p. 158 - 167.
    senegal peanut basin - sub-saharan africa - native shrub communities - acid sandy soil - pearl-millet - fertility management - crop residue - piliostigma-reticulatum - guiera-senegalensis - carbon dynamics
    Low inherent fertility of tropical soils and degradation, nutrient deficiency and water stress are the key factors that hamper rainfed agriculture in semi-arid West Africa. Conservation Agriculture (CA) is currently promoted in the region as a technology to reduce soil degradation, mitigate the effect of droughts and increase crop productivity while reducing production costs. CA relies on the simultaneous use of three practices: (1) minimum or zero-tillage; (2) maintenance of a permanent soil cover and; (3) diversified profitable crop rotation. The most prominent aspect of CA for degraded lands in the semi-arid tropics would be the organic soil cover that impacts on the soil water balance, biological activity, soil organic matter build-up and fertility replenishment. Yet, the organic resources are the most limiting factor in Sahelian agroecosystems due to low biomass productivity and the multiple uses of crop residues, chiefly to feed the livestock. Hence, CA as such may hardly succeed in the current Sahelian context unless alternative sources of biomass are identified. Alternatively, we propose: (1) to gradually rehabilitate the biomass production function of the soil through increased nutrient input and traditional water harvesting measures that have been promoted as “soil and water conservation” technologies in the Sahel, e.g. zaï, in order to restore soil hydrological properties as prerequisite to boosting biomass production; (2) to encourage during this restorative phase the regeneration of native evergreen multipurpose woody shrubs (NEWS) traditionally and deliberately associated to crops and managed the year around and; (3) to shift to classical, less labour intensive CA practices once appropriate levels of soil fertility and water capture are enough to allow increased agroecosystem primary productivity (i.e., an active ‘aggradation’ phase followed by one of conservation). The CA systems we propose for the Sahelian context are based on intercropping cereal crops and NEWS building on traditional technologies practiced by local farmers. Traditionally, NEWS are allowed to grow in croplands during the dry season; they reduce wind erosion, trap organic residues and capture the Harmattan dust, influence the soil hydraulics and favour soil biological activity under their canopies. They are coppiced at the end of the dry season, leaves and twigs remain as mulch while branches are collected for domestic fuel and other uses. Shoots re-sprouting during the rainy season are suppressed as weeds. Such CA systems have limited competition with livestock due to the poor palatability of the shrub green biomass, which may increase their acceptance by smallholders. Such aggradation–conservation strategy is not free of challenges, as it may imply initial soil disturbance that entail important labour investments, substantially change the structure and management of the cropping system (annual crop-perennial plant), and lead to emerging tradeoffs in the use of resources at different scales. This paper offers a state of the art around NEWS and their integration in relay intercropping CA systems, discusses the above mentioned challenges and the main research needs to address them
    HIV and severity of seasonal household food-related coping behaviors in rural Ghana
    Akrofi, S. ; Price, L.L. ; Struik, P.C. - \ 2012
    Ecology of Food and Nutrition 51 (2012)2. - ISSN 0367-0244 - p. 148 - 175.
    sub-saharan africa - hiv/aids - security - insecurity - strategies - frequency - diversity - aids
    In-depth research was conducted to evaluate the seasonal food insecurity of HIV-positive and HIV-negative farm households in the Eastern Region, Ghana. A Coping Strategy Index (CSI) was used to assess household food-related coping behaviors. HIV-positive farm households often relied on both less severe and more severe coping behaviors, had a higher CSI, cultivated a smaller field area, harvested fewer food species from farms and gardens, and obtained income from fewer sources than HIV-negative farm households in both the post-harvest and lean seasons. We conclude that food insecurity is more severe in HIV-positive than in HIV-negative farm households in both seasons
    Tourism revenue sharing policy at Bwindi Impenetrable National Park, Uganda: a policy arrangements approach
    Ahebwa, W.M. ; Duim, V.R. van der; Sandbrook, C. - \ 2012
    Journal of Sustainable Tourism 20 (2012)3. - ISSN 0966-9582 - p. 377 - 394.
    sub-saharan africa - western uganda - conservation - wildlife - management
    Debates on how to deliver conservation benefits to communities living close to protected high-biodiversity areas have preoccupied conservationists for over 20 years. Tourism revenue sharing (TRS) has become a widespread policy intervention in Africa and elsewhere where charismatic populations of wildlife remain. This paper analyzes TRS policy at Bwindi Impenetrable National Park (BINP), Uganda, from a policy arrangements perspective. It is based on data collected at BINP and three surrounding parishes, using qualitative methods. It concludes that the governance capacity of the TRS policy arrangement at BINP is low due to the structural incongruence of the dimensions of the policy arrangement (analyzed in terms of actors, resources, rules of the game and discourses). Despite the participatory rhetoric of policy reforms, the Uganda Wildlife Authority remains the most powerful actor: it has control over resources and consequently determines the rules of the game. Local communities do not feel adequately compensated for conservation costs. This issue is exacerbated by weak communications with local people, problems of fair distribution locally and nationally, corruption claims and powerful local elites. To maximize TRS’ ability to contribute to conservation through development, inequities in the design of the TRS and dispersion of benefits need to be addressed
    The World Starts With Me: A multilevel evaluation of a comprehensive sex education programme targeting adolescents in Uganda
    Rijsdijk, L.E. ; Bos, A.E.R. ; Ruiter, R.A.C. ; Leerlooijer, J.N. ; Haas, B. ; Schaalma, H.P. - \ 2011
    BMC Public Health 11 (2011). - ISSN 1471-2458 - 12 p.
    sub-saharan africa - planned behavior - reproductive health - condom use - interventions - metaanalysis - students
    Background This paper evaluates the effect of the World Starts With Me (WSWM), a comprehensive sex education programme in secondary schools in Uganda. The aim of the present study was to assess the effects of WSWM on socio-cognitive determinants of safe sex behaviour (delay; condom use and non-coercive sex). Methods A survey was conducted both before and immediately after the intervention among students in intervention (N = 853) and comparison (N = 1011) groups. A mixed model repeated measures analysis was performed to assess the effectiveness of the WSWM programme on the main socio-cognitive determinants of safe sex behaviour at post-test. A similar post-hoc comparison was made between schools based on completeness and fidelity of implementation of WSWM. Results Significant positive effects of WSMW were found on beliefs regarding what could or could not prevent pregnancy, the perceived social norm towards delaying sexual intercourse, and the intention to delay sexual intercourse. Furthermore, significant positive effects of WSWM were found on attitudes, self-efficacy and intention towards condom use and on self-efficacy in dealing with sexual violence (pressure and force for unwanted sex). A reversed effect of intervention was found on knowledge scores relating to non-causes of HIV (petting, fondling and deep kissing). A follow-up comparison between intervention schools based on completeness of the programme implementation revealed that almost all significant positive effects disappeared for those schools that only implemented up to 7 out of 14 lessons. Another follow-up analysis on the basis of implementation fidelity showed that schools with a "partial" fidelity score yielded more significant positive effects than schools with a "full" fidelity of implementation score. Conclusions The study showed an intervention effect on a number of socio-cognitive determinants. However, the effectiveness of WSWM could be improved by giving more systematic attention to the context in which such a programme is to be implemented. Implications for the systematic development and implementation of school-based safe sex interventions in Uganda will be discussed.
    Where artisanal mines and forest meet: Socio-economic and environmental impacts in the Congo Basin
    Ingram, V.J. ; Tieguhong, J.C. ; Schure, J.M. ; Nkamgnia, E. ; Tadjuidje, M.H. - \ 2011
    Natural Resources Forum 35 (2011)4. - ISSN 0165-0203 - p. 304 - 320.
    sub-saharan africa - gold mining communities - small-scale - mercury pollution - rural livelihoods - protected areas - child labor - ghana - management - tanzania
    While mineral exploitation can provide significant income and employment, it may negatively impact the environment, being ultimately detrimental to livelihoods in the long term. The consequences of mining are of concern in high value forest ecosystems such as the Sangha Tri-National (TNS) landscape covering Cameroon, the Central African Republic and Republic of the Congo. This paper captures the socio-economic and environmental impacts of small-scale mining in the TNS. Using structured questionnaires, consultations and observation, diamonds and gold were found to contribute directly to the livelihoods of at least 5% of the landscape's population. Although up to eight income-generating strategies are used, mining contributes on average to 65% of total income and is used mainly to meet basic needs. A gold miner's average income is US$ 3.10 a day, and a diamond miner earns US$ 3.08, making them slightly wealthier than an average Cameroonian and three times wealthier than an average non-miner in the TNS. Environmental impacts were temporary, low impact and of limited scale. However, with mining likely to increase in the near future, an increasing population and miners' low environmental awareness, measures are needed to ensure and reinforce the positive impact of artisanal mining on livelihoods and maintain its low environmental footprint in the TNS landscape.
    Pathways for sustainable development of mixed crop livestock systems: Taking a livestock and pro-poor approach
    Tarawali, S.A. ; Herrero, M. ; Descheemaeker, K.K.E. ; Grings, E. ; Blmmel, M. - \ 2011
    Livestock Science 139 (2011)1-2. - ISSN 1871-1413 - p. 11 - 21.
    sub-saharan africa - improving water productivity - farming systems - dairy production - west-africa - methane - intensification - management - emissions - dynamics
    Mixed crop livestock systems provide the majority of the cereal and livestock domestic products for households in developing countries. We explore the question of whether such systems can respond to increasing demands for livestock products without compromising future livelihoods of the poor or the environment. We consider how the potential of smallholder farmers to address future milk and meat demands as livestock system transition may be impacted by the trajectory of intensification, the type of livestock commodity and the changing economic circumstances. Examples of ruminant feeding and management options with the potential to increase productivity and mitigate negative environmental impacts, notably greenhouse gases and the use of land and water in the context of developing country crop livestock systems are presented. However, such technical dimensions need to be realistically and practically considered in the context of changing market demands. Furthermore, if crop livestock systems in developing countries are to benefit today's smallholder farmers, radically different approaches will be needed. Equal importance will need to be given to technology based production and efficiency enhancing dimensions together with innovative and practical approaches encompassing institutional, policy and market solutions often in a value chain context
    Classification, Characterisation, and Use of Small Wetlands in East Africa
    Sakane, N.S. ; Alvarez, M.C. ; Becker, M. ; Böhme, B. ; Handa, C. ; Kamiri, H.W. ; Langensiepen, M. ; Menz, G. ; Misana, S. ; Mogha, N.G. ; Möseler, B.M. ; Mwita, E.J. ; Oyieke, H.A. ; Wijk, M.T. van - \ 2011
    Wetlands 31 (2011)6. - ISSN 0277-5212 - p. 1103 - 1116.
    sub-saharan africa - west-africa - opportunities - management - impacts
    Small wetlands in Kenya and Tanzania cover about 12 million ha and are increasingly converted for agricultural production. There is a need to provide guidelines for their future protection or use, requiring their systematic classification and characterisation. Fifty-one wetlands were inventoried in 2008 in four contrasting sites, covering a surveyed total area of 484 km2. Each wetland was subdivided into sub-units of 0.5–458 ha based on the predominant land use. The biophysical and socio-economic attributes of the resulting 157 wetland sub-units were determined. The wetland sub-units were categorized using multivariate analyses into five major cluster groups. The main wetland categories comprised: (1) narrow permanently flooded inland valleys that are largely unused; (2) wide permanently flooded inland valleys and highlands floodplains under extensive use; (3) large inland valleys and lowland floodplains with seasonal flooding under medium use intensity; (4) completely drained wide inland valleys and highlands floodplains under intensive food crop production; and (5) narrow drained inland valleys under permanent horticultural production. The wetland types were associated with specific vegetation forms and soil attributes. Agricultural land use of wetlands was linked to their physical accessibility and the availability of adjacent upland areas, irrespective of wetland size or soil type.
    A comparison of time series similarity measures for classification and change detection of ecosystem dynamics
    Lhermitte, S. ; Verbesselt, J. ; Verstraeten, W.W. ; Coppin, P. - \ 2011
    Remote Sensing of Environment 115 (2011)12. - ISSN 0034-4257 - p. 3129 - 3152.
    land-cover classification - conterminous united-states - nino-southern oscillation - rangeland vegetation type - finding coupled patterns - change-vector analysis - satellite sensor data - sub-saharan africa - leaf-area index - avhrr ndvi data
    Time series of remote sensing imagery or derived vegetation indices and biophysical products have been shown particularly useful to characterize land ecosystem dynamics. Various methods have been developed based on temporal trajectory analysis to characterize, classify and detect changes in ecosystem dynamics. Although time series similarity measures play an important role in these methods, a quantitative comparison of the similarity measures is lacking. The objective of this study was to provide an overview and quantitative comparison of the similarity measures in function of varying time series and ecosystem characteristics, such as amplitude, timing and noise effects. For this purpose, the performance was evaluated for the commonly used similarity measures (D), ranging from Manhattan (DMan), Euclidean (DE) and Mahalanobis (DMah) distance measures, to correlation (DCC), Principal Component Analysis (PCA; DPCA) and Fourier based (DFFT,D¿,DFk) similarities. The quantitative comparison consists of a series of Monte-Carlo simulations based on subsets of global MODIS Normalized Difference Vegetation index (NDVI) and Enhanced Vegetation Index (EVI) and Leaf Area Index (LAI) data. Results of the simulations reveal four main groups of time series similarity measures with different sensitivities: (i) DMan, DE, DPCA, DFk quantify the difference in time series values, (ii) DMah accounts for temporal correlation and non-stationarity of variance, (iii) DCC measures the temporal correlation, and (iv) the Fourier based DFFT and D¿ show their specific sensitivity based on the selected Fourier components. The difference measures show relatively the highest sensitivity to amplitude effects, whereas the correlation based measures are highly sensitive to variations in timing and noise. The Fourier based measures, finally, depend highly on the signal to noise ratio and the balance between amplitude and phase dominance. The heterogeneity in sensitivity of each D stresses the importance of (i) understanding the time series characteristics before applying any classification of change detection approach and (ii) defining the variability one wants to identify/account for. This requires an understanding of the ecosystem dynamics and time series characteristics related to the baseline, amplitude, timing, noise and variability of the ecosystem time series. This is also illustrated in the quantitative comparison, where the different sensitivities of D for the NDVI, EVI, and LAI data relate specifically to the temporal characteristics of each data set. Additionally, the effect of noise and intra- and interclass variability is demonstrated in a case study based on land cover classification.
    Strengthening understanding and perceptions of mineral fertilizer use among smallholder farmers: evidence from collective trials in western Kenya
    Misiko, M. ; Tittonell, P.A. ; Giller, K.E. ; Richards, P. - \ 2011
    Agriculture and Human Values 28 (2011)1. - ISSN 0889-048X - p. 27 - 38.
    sub-saharan africa - management - heterogeneity - agriculture - gradients
    It is widely recognized that mineral fertilizers must play an important part in improving agricultural productivity in western Kenyan farming systems. This paper suggests that for this goal to be realized, farmers’ knowledge must be strengthened to improve their understanding of fertilizers and their use. We analyzed smallholder knowledge of fertilizers and nutrient management, and draw practical lessons from empirical collective fertilizer-response experiments. Data were gathered from the collective fertilizer-response trials, through focus group discussions, by participant observation, and via in-depth interviews representing 40 households. The collective trials showed that the application of nitrogen (N) or phosphorous (P) alone was insufficient to enhance yields in the study area. The response to P on the trial plots was mainly influenced by incidences of the parasitic Striga weed, by spatial variability or gradients in soil fertility of the experimental plots, and by interactions with N levels. These results inspired farmer to design and conduct experiments to compare crop performance with and without fertilizer, and between types of fertilizers, or responses on different soils. Participating farmers were able to differentiate types of fertilizer, and understood rates of application and the roles of respective fertilizers in nutrient supply. However, notions were broadly generated by unsteady yield responses when fertilizers were used across different fertility gradients, association with high cost (especially if recommended rates were to be applied), association of fertilizer use with hybrids and certain crops, historical factors, among other main aspects. We identified that strengthening fertilizer knowledge must be tailored within existing, albeit imperfect, systems of crop and animal husbandry. Farmers’ perceptions cannot be changed by promoting more fertilizer use alone, but may require a more basic approach that, for example, encourages farmer experimentation and practices to enhance soil properties such as carbon build-up in impoverished local soils.
    Drivers of land use change and household determinants of sustainability in smallholder farming systems of Eastern Uganda
    Ebanyat, P. ; Ridder, N. de; Jager, A. de; Delve, R.J. ; Bekunda, M. ; Giller, K.E. - \ 2010
    Population and Environment 31 (2010)6. - ISSN 0199-0039 - p. 474 - 506.
    soil fertility management - sub-saharan africa - cover change - nutrient balances - brazilian amazon - level evidence - southern mali - use patterns - dynamics - agriculture
    Smallholder farming systems in sub-Saharan Africa have undergone changes in land use, productivity and sustainability. Understanding of the drivers that have led to changes in land use in these systems and factors that influence the systems’ sustainability is useful to guide appropriate targeting of intervention strategies for improvement. We studied low input Teso farming systems in eastern Uganda from 1960 to 2001 in a place-based analysis combined with a comparative analysis of similar low input systems in southern Mali. This study showed that policy-institutional factors next to population growth have driven land use changes in the Teso systems, and that nutrient balances of farm households are useful indicators to identify their sustainability. During the period of analysis, the fraction of land under cultivation increased from 46 to 78%, and communal grazing lands nearly completely disappeared. Cropping diversified over time; cassava overtook cotton and millet in importance, and rice emerged as an alternative cash crop. Impacts of political instability, such as the collapse of cotton marketing and land management institutions, of communal labour arrangements and aggravation of cattle rustling were linked to the changes. Crop productivity in the farming systems is poor and nutrient balances differed between farm types. Balances of N, P and K were all positive for larger farms (LF) that had more cattle and derived a larger proportion of their income from off-farm activities, whereas on the medium farms (MF), small farms with cattle (SF1) and without cattle (SF2) balances were mostly negative. Sustainability of the farming system is driven by livestock, crop production, labour and access to off-farm income. Building private public partnerships around market-oriented crops can be an entry point for encouraging investment in use of external nutrient inputs to boost productivity in such African farming systems. However, intervention strategies should recognise the diversity and heterogeneity between farms to ensure efficient use of these external inputs.
    Striga infestation in northern Cameroon: Magnitude, dynamics and implications for managament
    Ayongwa, G.C. ; Stomph, T.J. ; Hoevers, R. ; Ngoumou, T.N. ; Kuyper, T.W. - \ 2010
    NJAS Wageningen Journal of Life Sciences 57 (2010)2. - ISSN 1573-5214 - p. 159 - 165.
    soil fertility management - sub-saharan africa - hermonthica control - savanna zone - nigeria - land - sahel - productivity - cultivation - challenges
    Surveys of Striga (S. hermonthica (Del.) Benth.) infestation in northern Cameroon over the period 1987–2005 assessed Striga dynamics and evaluated its control strategies. In that period the percentage of Striga-infested fields increased in North and Far-North Provinces. Striga incidence increased more in maize fields than in the already heavily infested sorghum fields, where it remained almost constant. During the study period increased land pressure led to a reduction in the use of fallow and a higher frequency of cereal (mono-) cropping. Yields from farmers’ fields did not correlate with Striga incidence, confirming farmers’ prioritization of soil fertility, weeds, and labour for weeding as production constraints, rather than Striga. We discuss how conceptualization of Striga as a weed in the research arena may have led to a misunderstanding of farmers’ constraints. The decline of the cotton industry reduced farmers’ access to fertilizers, while access to organic manure remained limited, increasing the soil fertility constraint. We conclude that two decades of emphasis on Striga were unsuccessful. Enhanced crop yield through soil fertility management should be the entry point to tackle low yields and further worsening of the Striga situation
    Globalization vs. localization: global food challenges and local sollutions
    Quaye, W. ; Jongerden, J.P. ; Essegbey, G. ; Ruivenkamp, G.T.P. - \ 2010
    International Journal of Consumer Studies 34 (2010)3. - ISSN 1470-6423 - p. 357 - 366.
    sub-saharan africa - sensory evaluation - rice - politics - tourism
    The objective of this study was to examine the effect of global-local interactions on food production and consumption in Ghana, and identify possible local solutions. Primary data were collected using a combination of quantitative-qualitative methods, which included focus group discussions and one-on-one interviews. Approximately 450 household heads were randomly selected and interviewed between August 2007 and August 2008 in Eastern, Central, Upper East and Northern Regions of Ghana. Findings revealed increasing consumption of foreign rice as opposed to decreasing consumption of local rice and other staples like millet, sorghum and yam because of global-local interactions. However, opportunities exist to re-localize production-consumption patterns through the use of 'glocal foods' like improved 'koose and waakye'. Referencing the situation in Ghana, the study recommends improved production and processing practices backed with appropriate technologies that reflect changing consumption dynamics in order to take full advantage of opportunities created as a result of global-local interactions.
    Environmental Systems and Local Actors: Decentralizing Environmental Policy in Uganda
    Oosterveer, P.J.M. ; Vliet, B.J.M. van - \ 2010
    Environmental Management 45 (2010)2. - ISSN 0364-152X - p. 284 - 295.
    sub-saharan africa - service delivery - politics - reform - management - governance - community
    In Uganda, environmental and natural resource management is decentralized and has been the responsibility of local districts since 1996. This environmental management arrangement was part of a broader decentralization process and was intended to increase local ownership and improve environmental policy; however, its implementation has encountered several major challenges over the last decade. This article reviews some of the key structural problems facing decentralized environmental policy in this central African country and examines these issues within the wider framework of political decentralization. Tensions have arisen between technical staff and politicians, between various levels of governance, and between environmental and other policy domains. This review offers a critical reflection on the perspectives and limitations of decentralized environmental governance in Uganda. Our conclusions focus on the need to balance administrative staff and local politicians, the mainstreaming of local environmental policy, and the role of international donors
    The Economic Impact of Medical Migration: An Overview of the Literature
    Rutten, M.M. - \ 2009
    The World Economy 2009(32) (2009)2. - ISSN 0378-5920 - p. 291 - 325.
    sub-saharan africa - health-care workers - brain-drain - developing-countries - human-resources - nurses - professionals - doctors - crisis - restrictions
    This paper provides an overview of the evidence and applied literature on medical migration. The economic impacts of medical migration have been little researched, causing a polarisation in the debate between its critics and its proponents. The paucity of quantitative studies may be explained by the lack of comprehensive and consistent data. Investments in statistical resources on medical migration are therefore a major priority. The available evidence suggests that particularly English-speaking countries in Sub-Saharan African countries and the Caribbean with relatively few health workers and a high disease burden suffer most from the medical brain drain. However, the exodus of health workers is not the main cause of the health status crisis, but rather a symptom of deeper underlying problems, which often extend beyond the health sector towards the broader economic and political environment. In such situations, medical brain drain does pose challenges for human resource management and health service delivery. The only effective and long-term sustainable policy is one that addresses the underlying push and pull factors. Reforms have to be country-led, but may be supported via temporary migration schemes, remittances, enhancement of diaspora networks, and financial aid for which a strong moral case exists.
    Conservation agriculture and smallholder farming in Africa: The heretics' view
    Giller, K.E. ; Witter, E. ; Corbeels, M. ; Tittonell, P.A. - \ 2009
    Field Crops Research 114 (2009)1. - ISSN 0378-4290 - p. 23 - 34.
    soil carbon sequestration - sub-saharan africa - biological nitrogen-fixation - semiarid west-africa - tillage systems - organic-matter - sustainable agriculture - cropping systems - southwestern nigeria - water conservation
    Conservation agriculture is claimed to be a panacea for the problems of poor agricultural productivity and soil degradation in sub-Saharan Africa (SSA). It is actively promoted by international research and development organisations, with such strong advocacy that critical debate is stifled. Claims for the potential of CA in Africa are based on widespread adoption in the Americas, where the effects of tillage were replaced by heavy dependence on herbicides and fertilizers. CA is said to increase yields, to reduce labour requirements, improve soil fertility and reduce erosion. Yet empirical evidence is not clear and consistent on many of these points nor is it always clear which of the principles of CA contribute to the desired effects. Although cases can be found where such claims are supported there are equally convincing scientific reports that contradict these claims. Concerns include decreased yields often observed with CA, increased labour requirements when herbicides are not used, an important gender shift of the labour burden to women and a lack of mulch due to poor productivity and due to the priority given to feeding of livestock with crop residues. Despite the publicity claiming widespread adoption of CA, the available evidence suggests virtually no uptake of CA in most SSA countries, with only small groups of adopters in South Africa, Ghana and Zambia. We conclude that there is an urgent need for critical assessment under which ecological and socio-economic conditions CA is best suited for smallholder farming in SSA. Critical constraints to adoption appear to be competing uses for crop residues, increased labour demand for weeding, and lack of access to, and use of external inputs
    Urban environmental services and the state in East Africa; between neo-developmental and network governance approaches
    Oosterveer, P.J.M. - \ 2009
    Geoforum 40 (2009)6. - ISSN 0016-7185 - p. 1061 - 1068.
    sub-saharan africa - private-sector - water - uganda - sanitation - politics - tanzania - kampala - consolidation - perspective
    Although governments are generally expected to provide environmental services such as sanitation and solid waste collection for their citizens, most (municipal) governments in Sub-Saharan Africa seem hardly able to take up this task. Without ignoring the lack of material resources resulting from poverty, there are other structural causes for this failure as well and related to the role of the state. Since independence, the state in Africa has been debated in political as well as in academic circles and opposing views can still be discerned today. While some promote a strong interventionist state which can effectively enhance development, others consider introducing network governance by involving various societal actors in combination with different levels of government a more promising alternative. After presenting an historical overview, in this paper I will summarize this debate and discuss future options for East African authorities for providing more effective and sustainable urban environmental infrastructures and services
    Diversity and mobility in households with children orphaned by AIDS in Couffo, Benin
    Fagbemissi, R.C. ; Lie, R. ; Leeuwis, C. - \ 2009
    African Journal of AIDS Research 8 (2009)3. - ISSN 1608-5906 - p. 261 - 274.
    sub-saharan africa - hiv/aids - impact - population - knowledge - tanzania - uganda - health - rakai - women
    This paper characterises children orphaned by AIDS in the Couffo region of Benin. A 2006 census conducted for the research revealed a total of 315 such orphans, aged 0 to 14 years, within 88 households. Seventy-one percent of these children were under the care of their mothers or grandmothers, 68% were fatherless, 58% were between the ages of 7 and 12, and 68% were in primary school. An in-depth study of the orphans’ lives, undertaken to complement the census, revealed that these orphans were highly mobile between households, with almost 50% of them moving homes within a six-month period. An analysis of this phenomenon found that orphan mobility was a deliberate household strategy to manage orphanhood. Tensions arising out of care arrangements and resource allocation were among the main reasons for the high degree of orphan mobility. The context of orphan mobility also highlighted the practical role the orphans were able to fulfil within the affected households. The findings show that orphan mobility is a social phenomenon with two functions: on one hand, it may help HIV/AIDS-affected households to manage the increase in the number of orphans; on the other, it can provide an opportunity for orphans to move to a ‘safer’ environment anytime they do not feel secure. The implications for institutions providing care to orphans were also identified. Among other things, we recommend that a distinction be made between the main caregiver and the ‘endorser’ of an orphan as this was found to be an important difference. We also recommended that a distinction be made between orphans under and over the age of 10. For instance, children in the age group 10–14 years should be defined as ‘pre-adults,’ as their position within the household and their needs for services are different from those of orphans under age 10. Keywords: care provision, census, children, household resources, resource allocation, rural communities, sociology, West Africa
    Linking participatory and GIS-based land use planning methods; A case study from Burkina Faso
    Hessel, R. ; Berg, J. van den; Kabore, O. ; Kekem, A.J. van; Verzandvoort, S.J.E. - \ 2009
    Land Use Policy 26 (2009)4. - ISSN 0264-8377 - p. 1162 - 1172.
    soil fertility management - sub-saharan africa - desertification debate - degradation - views - sahel
    Sustainable land use planning is crucial for realizing the aim of food security and for combating land degradation in the Sahel. A participatory land use planning workshop was organised in a village in the eastern region of Burkina Faso to investigate land use problems, their causes, effects and possible solutions. Participatory research tools and GIS were combined to get insight into possible conflicts or synergies between different land use options as mapped by different ethnic groups. Pictograms were used to locate alternative land use options on the map, after which they were digitised for analysis with GIS. The workshop confirms the importance of integrating scientific and local knowledge to develop concrete options for sustainable land use that fit to local realities and aspirations. Local people are knowledgeable about the driving forces behind land degradation, they take actions to combat the effects of degradation, and they have concrete ideas about alternative land use options. The use of GIS proved its added value in the participatory process of integrated land use planning. The maps that were produced also facilitate discussions between community members, researchers and government representatives at the regional level, both regarding current land use problems and regarding alternative options as perceived by the local population.
    Farm nitrogen flows of four farmer field schools in Kenya
    Beek, C.L. ; Onduru, D.D. ; Gachimbi, L.N. ; Jager, A. de - \ 2009
    Nutrient Cycling in Agroecosystems 83 (2009)1. - ISSN 1385-1314 - p. 63 - 72.
    monitoring nutrient flows - sub-saharan africa - economic-performance - systems nutmon - 3 districts - management - balances - highlands
    Re-use of nutrients within farming systems contributes to sustainable food production in nutrient limited production systems. Re-use is established when nutrients pass through several farm compartments before they leave the farm via marketable products. In this paper re-use of nitrogen is examined as an indicator for sustainable soil fertility management. Re-use (RU, kg farm-1) was defined as the amount of nitrogen that was translocated within one farm divided by the sum of transitions between farm compartments within a farm. In 2002, a total of 101 farms belonging to 4 farmer field schools in Kenya were analysed using the NUTMON (now known as MonQI) toolbox. The farms were distributed over 4 farmer field schools located in two agro-ecological zones.RUwas positively related to the net farm income and to crop yields. However, data were scattered and often local farm conditions veiled the relation between nitrogen management strategies and farm performances. The results of this paper demonstrate that different agro-ecological zones with diverse production constraints have developed different in-farm nitrogen management strategies that are best adapted to the local conditions, but may have different environmental impacts.
    The homogenization effect of land titling on investment incentives: evidence from Peru
    Fort Meyer, R.A. - \ 2008
    NJAS Wageningen Journal of Life Sciences 55 (2008)4. - ISSN 1573-5214 - p. 325 - 343.
    investering - stimulansen - traditioneel pachtstelsel - pachtstelsel - eigendomsverkrijging - investeringsbeslissingen - investment - incentives - traditional tenure systems - tenure systems - acquisition of ownership - investment decisions - sub-saharan africa - property-rights - impact
    Land titling programmes have been widely promoted as a necessary condition for enhancing farmer¿s incentives to invest in their land. The justification for public intervention of this type is increasingly questioned on the grounds of its limitation to replace or improve the effect of informal or customary rights already in place. If the main aim of the programme is to formalize previous land rights and its procedure is based on the recognition of informal documents and reliance on community rules, it could in fact contribute to increased farmer¿s tenure security and therefore boost land investments. We explored this relationship for a sample of Peruvian farmers who were part of a state-led land titling programme that shared the aforementioned characteristics. Using retrospective information on the type of informal documents that parcels had before the start of the programme we were able to categorize the parcels at two levels of initial tenure security. The effect of titling on investments was then analysed for these two groups, using a difference-in-differences estimation technique. The results show that there is a positive effect of titling on the probability of making investments as well as on the value of investments for both groups of parcels, but also prove that the impact of titling is greater for parcels with previously low levels of tenure security. This effect could be almost entirely attributed to changes in farmer¿s willingness to invest and not to better access to credit.
    Influence of nutrient management strategies on variability of soil fertility, crop yields and nutrient balances on smallholder farms in Zimbabwe
    Zingore, S. ; Murwira, H.K. ; Delve, R.J. ; Giller, K.E. - \ 2007
    Agriculture, Ecosystems and Environment 119 (2007)1-2. - ISSN 0167-8809 - p. 112 - 126.
    sub-saharan africa - spatial variability - organic-matter - eastern uganda - systems - flows - allocation - dynamics - ethiopia - fallows
    An improved understanding of soil fertility variability and farmers' resource use strategies is required for targeting soil fertility improving technologies to different niches within farms. We measured the variability of soil fertility with distance from homesteads on smallholder farms of different socio-economic groups on two soil types, a granite sand and a red clay, in Murewa, northeast Zimbabwe. Soil organic matter, available P and CEC decreased with distance from homestead on most farms. Soil available P was particularly responsive to management, irrespective of soil type, as it was more concentrated on the plots closest to homesteads on wealthy farms (813 mg kg(-1)), compared with plots further from homesteads and all plots on poor farms (2-6 mg kg(-1)). There was a large gap in amounts of mineral fertilizers used by the wealthiest farmers (> 100 kg N and > 15 kg P per farm; 39 kg N ha(-1) and 7 kg P ha(-1)) and the poorest farmers (<20 kg N and <10 kg P per farm; 19 kg N ha(-1) and 4 kg P ha(-1)). The wealthy farmers who owned cattle also used large amounts of manure, which provided at least 90 kg N and 25 kg P per farm per year (36 kg N ha(-1) and 10 kg P ha(-1)). The poor farmers used little or no organic sources of nutrients. The wealthiest farmers distributed mineral fertilizers evenly across their farms, but preferentially targeted manure to the plots closest to the homesteads, which received about 70 kg N and 18 kg P per plot (76 kg N ha(-1) and 21 kg P ha(-1)) from manure compared with 23 kg N and 9 kg P per plot on the mid-fields (26 kg N ha(-1) and 10 kg P ha(-1)), and 10 kg N and 1 kg P per plot (and ha-1) on the outfields. Crop allocation on the homefields was most diversified on the wealthiest farms where maize was allocated 41% of the area followed by grain legumes (24%) and paprika (21%). Maize was allocated at least 83% of the homefields on farms with less access to resources. All the farmers invariably applied nutrients to maize but little to groundnut. Maize grain yields were largest on the homefields on the wealthy farms (2.7-5.0 t ha(-1)), but poor across all fields on the poor farms (0.3-1.9 t ha(-1)). Groundnut grain yields showed little difference between farms and plots. N and P partial balances were largest on the wealthy farms, although these fluctuated from season to season (-20 to +80 kg N per farm and 15-30 kg P per farm; average 21 kg N ha(-1) and 8 kg P ha(-1)). The partial balances on the wealthy farms were largest on the homefield (20-30 kg N and 13 kg P per plot; > 26 kg N ha(-1) and > 13 kg P ha(-1)),but decreased to 10-20 N and 6-9 kg P per plot (<20 kg N ha(-1) and 13 kg P ha(-1)) in mid-fields and -7 to +10 kg N and -1 to +1 kg P per plot (<10 kg N ha(-1) and <2 kg P ha(-1)) in the outfields. N and P balances differed little across plots on the poor farms (-2 to +4 kg per plot; -5 to +4 kg ha(-1)) due to limited nutrients applied and small off-take from small harvests. This study highlights the need to consider soil fertility gradients and the crop and nutrient management patterns creating them when designing options to improve resource use efficiency on smallholder farms. (c) 2006 Elsevier B.V. All rights reserved.
    Ecologists can enable communities to implement malaria vector control in Africa
    Mukabana, W.R. ; Kannady, K. ; Kiama, G.M. ; Ijumba, J.N. ; Mathenge, E.M. ; Kiche, I. ; Nkwengulila, G. ; Mboera, L.E.G. ; Mtasiwa, D. ; Yamagata, Y. ; Schayk, I. van; Knols, B.G.J. ; Lindsay, S.W. ; Caldas de Castro, M. ; Mshinda, H. ; Tanner, M. ; Fillinger, U. ; Killeen, G.F. - \ 2006
    Malaria Journal 5 (2006). - ISSN 1475-2875 - 14 p.
    insecticide-treated nets - dar-es-salaam - sub-saharan africa - anopheles-gambiae - western kenya - spatial-distribution - larval habitats - integrated control - mosquito larvae - appraisal ruma
    Background - Integrated vector management (IVM) for malaria control requires ecological skills that are very scarce and rarely applied in Africa today. Partnerships between communities and academic ecologists can address this capacity deficit, modernize the evidence base for such approaches and enable future scale up. Methods - Community-based IVM programmes were initiated in two contrasting settings. On Rusinga Island, Western Kenya, community outreach to a marginalized rural community was achieved by University of Nairobi through a community-based organization. In Dar es Salaam, Tanzania, Ilala Municipality established an IVM programme at grassroots level, which was subsequently upgraded and expanded into a pilot scale Urban Malaria Control Programme with support from national academic institutes. Results - Both programmes now access relevant expertise, funding and policy makers while the academic partners benefit from direct experience of community-based implementation and operational research opportunities. The communities now access up-to-date malaria-related knowledge and skills for translation into local action. Similarly, the academic partners have acquired better understanding of community needs and how to address them. Conclusion - Until sufficient evidence is provided, community-based IVM remains an operational research activity. Researchers can never directly support every community in Africa so community-based IVM strategies and tactics will need to be incorporated into undergraduate teaching programmes to generate sufficient numbers of practitioners for national scale programmes. Academic ecologists at African institutions are uniquely positioned to enable the application of practical environmental and entomological skills for malaria control by communities at grassroots level and should be supported to fulfil this neglected role.
    Within-farm soil fertility gradients affect response of maize to fertiliser application in western Kenya
    Vanlauwe, B. ; Tittonell, P.A. ; Mukalama, J. - \ 2006
    Nutrient Cycling in Agroecosystems 76 (2006)2-3. - ISSN 1385-1314 - p. 171 - 182.
    northern guinea savanna - sub-saharan africa - resource-management - highlands - quality - systems - crops
    Different fields within a farm have been observed to have different soil fertility status and this may affect the response of a maize crop to applied N, P, and K fertiliser. A limiting nutrient trial was carried out at six farms each, in three districts of Western Kenya. In each of the farms, the following treatments were laid out in three fields with different soil fertility status at different distances from the homestead (close, mid-distance, remote fields): no inputs, application of NPK, NP, NK, or PK fertiliser (urea, triple super phosphate, KCl) to maize. Total soil N decreased at all sites with distance to the homestead (from 1.30 to 1.06 g kg-1), as did Olsen-P (from 10.5 to 2.3 mg kg-1). Grain yields in the no-input control plots reflected this decrease in soil fertility status with distance to the homestead (from 2.59 to 1.59 t ha-1). In the NPK treatments, however, this difference between field types disappeared (from 3.43 to 3.98 t ha-1), indicating that N and P are the major limiting nutrients in the target areas. Response to applied N was related to the soil total N content in Aludeka and Shinyalu, but not in Emuhaia, probably related to the high use of partially decomposed organic inputs with limited N availability. Consequently, response to applied N decreased with distance to the homestead in Aludeka (from 0.95 kg kg-1 relative yield to 0.55 kg kg-1) and Shinyalu (from 0.76 kg kg-1 to 0.47 kg kg-1), but not in Emuhaia (from 0.75 kg kg-1 to 0.68 kg kg-1). Response to applied P was related to the soil Olsen-P content at all sites. While for farms with a relatively high Olsen-P gradient, response to applied P decreased with distance to the homestead (from 0.99 kg kg-1 to 0.68 kg kg-1), large variability in Olsen-P gradients across field types among farms within a specific site often masked clear differences in response to P between field types for a specific site. Clear scope for field-specific fertiliser recommendations exists, provided these are based on local soil knowledge and diagnosis. Scenario analysis, using farm-scale modelling tools, could assist in determining optimum allocation strategies of scarcely available fertiliser for maximum fertiliser use efficiency
    Can arbuscular mycorrhizal fungi contribute to Striga management on cereals in Africa?
    Lendzemo, V.W. ; Ast, A. van; Kuyper, T.W. - \ 2006
    Outlook on Agriculture 35 (2006)4. - ISSN 0030-7270 - p. 307 - 311.
    sub-saharan africa - hermonthica control - soil disturbance - sorghum - maize - crops - growth - biotechnology - colonization - inoculation
    Witchweeds (Striga spp.) are important root parasites of many cereal and legume crops in savanna and Sahelian regions of Africa. Evidence on the possible role of soil pathogenic bacteria and fungi in Striga control has been obtained. Here, the authors report that arbuscular mycorrhizal (AM) fungi can also affect the interaction between Striga and cereals. AM fungi negatively impacted on Striga seed germination, reduced the number of Striga seedlings attaching and emerging, and delayed the emergence time of Striga both in pot and field experiments. AM fungi enhanced the performance of the cereal host, allowing it to withstand Striga damage better. Management strategies for AM fungi for Striga control as part of an integrated management system are discussed
    Turning the tides of soil degradation in Africa: capturing the reality and exploring opportunities
    Muchena, F.N. ; Onduru, D.D. ; Gachini, G.N. ; Jager, A. de - \ 2005
    Land Use Policy 22 (2005)1. - ISSN 0264-8377 - p. 23 - 31.
    monitoring nutrient flows - farming systems nutmon - sub-saharan africa - of-the-art - fertility management - economic-performance - balances - productivity - kenya - agriculture
    Soil degradation means loss of biological and economic productivity of the land. Measurements of land degradation need to take cognizance of land properties (e.g. soil, water and vegetation) as well as productivity indicators. While land degradation in sub-Saharan Africa is a subject of an on-going debate, conflicting perspectives arise about its extent at regional and at lower scales, about methodologies and robustness of indicators and the impacts of past and present degradation on food security, about rural livelihoods in general, and on African posterity. This paper presents evidence of land degradation from selected case studies across East Africa, and analyses them against the robustness of indicators used at regional, national and lower scales in order to unravel the hidden myths and realities of land degradation. The results are corroborated against time-series such as yields of major crops, environmental data (rainfall, soil fertility) and management data. Land degradation assessments need to move away from empty rhetoric to capturing reality by integrating effects of farm management practices and technologies, including their social and institutional dimensions, on soil loss, yields and nutrient budgets. Influencing factors and socio-economic environments surrounding land degradation and the specific environments under which degradation takes place should not be overlooked
    Rationalizing Historical successes of malaria control in Africa in terms of mosquito resource availabilty management
    Killeen, G.F. ; Seyoum, A. ; Knols, B.G.J. - \ 2004
    American Journal of Tropical Medicine and Hygiene 71 (2004)2 (S). - ISSN 0002-9637 - p. 87 - 93.
    entomologic inoculation rates - semifield experimental huts - sub-saharan africa - anopheles-gambiae - plasmodium-falciparum - environmental-management - passive zooprophylaxis - repellent plants - western kenya - host choice
    Environmental management of mosquito resources is a promising approach with which to control malaria, but it has seen little application in Africa for more than half a century. Here we present a kinetic model of mosquito foraging for aquatic habitats and vertebrate hosts that allows estimation of malaria transmission intensity by defining the availability of these resources as the rate at which individual mosquitoes encounter and use them. The model captures historically observed responses of malaria transmission to environmental change, highlights important gaps in current understanding of vector ecology, and suggests convenient solutions. Resource availability is an intuitive concept that provides an adaptable framework for models of mosquito population dynamics, gene flow, and pathogen transmission that can be conveniently parameterized with direct field measurements. Furthermore, the model presented predicts that drastic reductions of malaria transmission are possible with environmental management and elucidates an ecologic basis for previous successes of integrated malaria control in Africa before the advent of DDT or chloroquine. Environmental management for malaria control requires specialist skills that are currently lacking in sub-Saharan Africa where they are needed most. Infrastructure and human capacity building in clinical, public health, and environmental disciplines should therefore be prioritized so that growing financial support for tackling malaria can be translated into truly integrated control programs.
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