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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    Cotton as an entry point for soil fertility maintenance and food crop productivity in savannah agroecosystems - Evidence from a long-term experiment in southern Mali
    Ripoche, A. ; Crétenet, M. ; Corbeels, M. ; Affholder, F. ; Naudin, K. ; Sissoko, F. ; Douzet, J.M. ; Tittonell, P.A. - \ 2015
    Field Crops Research 177 (2015). - ISSN 0378-4290 - p. 37 - 48.
    organic-matter - nitrogen-fertilization - chemical-properties - nutrient dynamics - semiarid tropics - use efficiency - pearl-millet - burkina-faso - dry-matter - management
    Given the scarcity of manure and the limited land available for fallowing, cotton cultivation with its input credit schemes is often the main entry point for nutrients in cropping systems of West Africa. In an experiment carried out during 25 years in southern Mali, the crop and soil responses to organic fertilizer (=OF), inorganic fertilizer (=IF), and a combination of both (=OIF) were quantified and compared to a control treatment for a typical cotton-sorghum-groundnut rotation. From 1965 to 1979 (15 years, period 1), fertilizers were only applied on cotton and the control treatment was not fertilized. From 1980 to 1989 (10 years, period 2), the amount of manure applied was split between cotton and sorghum, and inorganic fertilizers were applied to the three crops. Inorganic fertilizers were also applied to plots with cotton and sorghum that were previously unfertilized control treatments. In favorable rainfall seasons maximum yields of fertilized treatments reached ca. 3.5 t ha-1 in the case of cotton and groundnuts, and ca. 2 t ha-1 in the case of sorghum. During period 1, cotton yields were steady (ca. 1 t ha-1) when no fertilizers were added. Cotton yields were 20% higher in the OF and OIF treatments than in the IF treatment. Sorghum and groundnut benefited from residual effects of fertilizer application on cotton leading to a 200% and 50% yield increase respectively compared to the control treatment. During period 2, yields of the three crops were similar across fertilized treatments. Groundnut yields in the OF treatment, and cotton yields in the OF and IF treatments were respectively 45%, 30% and 20% significantly higher than those in the respective control treatments. No added benefit on crop yields was observed from the combined use of inorganic and organic fertilizer. Soil nutrient contents (SOC, N, P, K) did not significantly change in any of the treatments after 25 years. Soil pH decreased in treatments receiving inorganic fertilizer. Despite low level of soil organic matter, crops responded to organic or inorganic fertilization and crop productivity over time was mostly influenced by the interaction between fertilization and rainfall variability. Our results highlight the role of cotton in West African landscapes as an entry point of nutrients via fertilization, which impacts positively on the productivity of the other crops in the rotation. Credit schemes by the cotton company for farmers to purchase fertilizer to which they would otherwise not have access are thus crucial for sustained crop productivity.
    Opportunities and challenges for investigating the environment-migration nexus
    Neumann, K. ; Hilderink, H. - \ 2015
    Human Ecology 43 (2015)2. - ISSN 0300-7839 - p. 309 - 322.
    climate-change impacts - rural out-migration - agent-based model - burkina-faso - population mobility - hurricane katrina - great-plains - land - vegetation - bangladesh
    Environmental change is an acknowledged factor influencing human migration. Analytical research regarding the relationship between the environment and human migration has increased in recent years yet still faces numerous hurdles, partly due to limited availability of suitable data. We review available data and methodologies for investigating the environment-migration nexus, identifying data inconsistencies resulting from the combination of different sources and illustrating the underlying reasons for them. We discuss a number of methods for investigating the environment-migration relationship, including frameworks and concepts; surveys; empirical, quantitative methods; and simulation approaches. Based on this overview, we offer recommendations for improved analyses of the environment-migration nexus including reporting data inconsistencies and uncertainties, combining approaches and data sources, and developing multiple-study approaches.
    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.
    Current performance of food safety management systems of dairy processing companies in Tanzania
    Kussaga, J.B. ; Luning, P.A. ; Tisekwa, B.P.M. ; Jacxsens, L. - \ 2015
    International Journal of Dairy Technology 68 (2015)2. - ISSN 1364-727X - p. 227 - 252.
    microbiological quality - raw-milk - pasteurized milk - developing-country - burkina-faso - bamako mali - haccp - industry - plants - implementation
    food safety management system (FSMS)-diagnostic instrument was applied in 22 dairy processing companies to analyse the set-up and operation of core control and assurance activities in view of the risk characteristics of the systems' context. Three clusters of companies were identified differing in levels of set-up and operation of this FSMS and system outputs, but all operated in a similar moderate-risk context. Microbiological assessment of products, environmental and hand samples indicated a poor to moderate food safety level. A two stage intervention approach has been proposed to enable commitment and sustainable improvement for the longer term.
    Combining malaria control with house electrification: adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems, Rusinga Island, western Kenya
    Oria, P.A. ; Alaii, J. ; Ayugi, M. ; Takken, W. ; Leeuwis, C. - \ 2015
    Tropical Medicine and International Health 20 (2015)8. - ISSN 1360-2276 - p. 1048 - 1056.
    treated bed nets - randomized controlled-trial - lake victoria - burkina-faso - risk - prevention - hiv - acceptability - motivation - villages
    objective To investigate community adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems (SMoTS) after 3- to 10-week use. methods Solar-powered mosquito trapping system, which also provided power for room lighting and charging mobile phones, were installed in houses in Rusinga Island, western Kenya. We used a structured checklist for observations and a semi-structured questionnaire for interviews in 24 homesteads. We also analysed the subject of 224 community calls to the project team for technical maintenance of SMoTS. results Most respondents cared for SMoTS by fencing, emptying and cleaning the trap. Our observations revealed that most traps were fenced, clean and in good working condition. A significantly higher proportion of community calls was lighting-related. Lighting was the main reason respondents liked SMoTS because it reduced or eliminated expenditure on kerosene. However, some respondents observed they no longer heard sounds of mosquitoes inside their houses. All respondents reportedly slept under insecticide-treated nets (ITNs) before receiving SMoTS. After receiving SMoTS, most respondents reportedly continued to use ITNs citing that the project advised them to do so. Some beach residents stopped using ITNs because they no longer heard mosquitoes or due to heat discomfort caused by lights. conclusion Electricity-related incentives played a greater role in encouraging adherence to recommended behaviours for proper deployment of SMoTS than the potential health benefits in the early stages of the intervention. Although energy-related financial incentives may play a role, they are insufficient to ensure adherence to health advice, even in the short term. Ongoing community engagement and research monitors and addresses adherence to recommended behaviours including continuation of current malaria control strategies.
    Environmental drivers of human migration in drylands - A spatial picture
    Neumann, K. ; Sietz, D. ; Hilderink, H. ; Janssen, P. ; Kok, M. ; Dijk, H. van - \ 2015
    Applied Geography 56 (2015). - ISSN 0143-6228 - p. 116 - 126.
    burkina-faso - northeast brazil - climate-change - land-use - drought - vulnerability - adaptation - dynamics - africa - management
    It is widely accepted that environmental change can influence human migration. In particular, the environment plays a role in migration processes in drylands, in which environmental change—including increasing variability of rainfall, increasing frequency of droughts, chronic water shortage, and land degradation—can heavily influence migration. However, systematic large-scale studies of the relationship between environmental factors and human migration are rare, and a global, consistent picture of environmental drivers of migration is lacking. In this study, we sought to fill this gap by analysing spatial patterns of environmental drivers of migration in drylands by performing a cluster analysis on spatially explicit global data. In this analysis, we focused explicitly on precipitation, aridity, drought, land degradation, soil constraints, and availability of cropland and pastures as potential environmental drivers of migration in drylands. In addition, we linked the identified clusters to two observed hotspots of out-migration—Burkina Faso and Northeast Brazil—to gauge the cluster results. Our results show that environmental drivers can be grouped into eight distinct clusters, and we identified the most severe environmental constraints for each cluster. These results suggest that out-migration—both in absolute and relative terms—occurs most frequently in a cluster that is constrained primarily by land degradation rather than water availability.
    A gendered users' perpective on decentralized primary health services in rural Tanzania
    Masanyiwa, Z.S. ; Niehof, A. ; Termeer, C.J.A.M. - \ 2015
    International Journal of Health Planning and Management 30 (2015)3. - ISSN 0749-6753 - p. 285 - 306.
    quality-of-care - developing-countries - decision space - burkina-faso - sector - uganda - zambia - districts - accountability - satisfaction
    Since the 1990s, Tanzania has been implementing health sector reforms including decentralization of primary healthcare services to districts and users. The impact of the reforms on the access, quality and appropriateness of primary healthcare services from the viewpoint of users is, however, not clearly documented. This article draws on a gendered users’ perspective to address the question of whether the delivery of gender-sensitive primary health services has improved after the reforms. The article is based on empirical data collected through a household survey, interviews, focus group discussions, case studies and analysis of secondary data in two rural districts in Tanzania. The analysis shows that the reforms have generated mixed effects: they have contributed to improving the availability of health facilities in some villages but have also reinforced inter-village inequalities. Men and women hold similar views on the perceived changes and appropriateness to women on a number of services. Gender inequalities are, however, reflected in the significantly low membership of female-headed households in the community health fund and their inability to pay the user fees and in the fact that women’s reproductive and maternal health needs are as yet insufficiently addressed. Although over half of users are satisfied with the services, more women than men are dissatisfied. The reforms appear to have put much emphasis on building health infrastructure and less on quality issues as perceived by users.
    Smallholder participation in large forestry programs: The camellia program in China
    Li, J. ; Bluemling, B. ; Dries, L.K.E. ; Feng, S. - \ 2014
    Outlook on Agriculture 43 (2014)1. - ISSN 0030-7270 - p. 45 - 51.
    influencing peoples participation - land-tenure arrangements - climate-change - investment incentives - burkina-faso - costa-rica - uncertainty - adoption - risk - management
    In recent years, many forestry projects have been implemented in developing countries. In China, a variety of large-scale afforestation and reforestation programmes have been carried out with multiple objectives, such as livelihood improvement and carbon sequestration. As in many developing countries, these projects have been implemented in a smallholder context. This paper investigates the determinants of smallholder participation in large forestry projects. Using the case of camellia, it explores the determinants of smallholder participation using a probit regression model. To distinguish between participation in international and government-run projects, a bivariate probit regression model is used. The findings show that only 37% of households in the sample had participated in the Camellia project; a major reason for the low participation rate is perceived tenure insecurity. The results of the bivariate probit model show that the education level of the household head and household size have a positive impact on the likelihood of household participation. The more 'off-farm' activities are taken up in a household, the less likely a household is to participate in an international project. For a government project, household size also has a positive impact on the likelihood of participation. Chinese forestry is diversifying since the devolution of forestland use rights, with a majority of households hesitating to invest, while some risk investment and others depend on government subsidies. The main policy implication is that, if the Chinese government wishes to achieve its goal of 1.68 million hectares of camellia, then improving tenure security is crucial.
    The role of breeding range, diet, mobility and body size in associations of raptor communities and land-use in a West African savannah
    Buij, R. ; Croes, B.M. ; Gort, G. ; Komdeur, J. - \ 2013
    Biological Conservation 166 (2013). - ISSN 0006-3207 - p. 231 - 246.
    long-term assessment - protected areas - southern-africa - burkina-faso - conservation - habitat - declines - cameroon - biodiversity - population
    To provide insight into raptor declines in western Africa, we investigated associations between land-use and raptor distribution patterns in Cameroon. We examined the role of breeding distribution, species’ migratory mobility, diet, body size, and thus area requirements, on 5-km scale patterns of raptor richness and abundance. We recorded 15,661 individuals, comprising 55 species during road surveys, spanning four annual cycles. Results revealed evidence for the importance of National Parks (N.P.’s), natural vegetation, humans, and cotton in shaping raptor assemblages, but responses differed between functional groups and biogeographical zones. Human populations and natural habitat, interacting with zone, were important predictors of Afrotropical raptor richness, and N.P.’s of Palearctic raptor richness. Areas cleared of natural habitat in the Guinea zone had comparatively rich and abundant large, small sedentary and migratory Afrotropical raptor assemblages, but humans limited positive effects. Palearctic raptor abundance peaked at higher levels of human land-use than Afrotropical raptors. Vertebrate-hunting Palearctic raptor richness was positively associated with cropland, while cotton and human land-use in the Inundation zone had a stronger negative impact on insectivorous Palearctic raptors. Richness of large sedentary raptors declined with increasing distance to N.P.’s, contrary to communal scavenger richness, which increased with human populations. Humans, habitat loss and cotton in the Inundation and Sudan zones had similar, negative effects on small sedentary and small migratory Afrotropical raptor assemblages. We conclude that increasing human populations, natural vegetation loss, and expanding cotton will negatively affect the majority of Afrotropical and insectivorous Palearctic raptors, while vertebrate-hunting Palearctic raptors may benefit from cropland expansion.
    The yield gap of major food crops in family agriculture in the tropics: Assessment and analysis through field surveys and modelling
    Affholder, F. ; Poeydebat, C. ; Corbeels, M. ; Scopel, E. ; Tittonell, P.A. - \ 2013
    Field Crops Research 143 (2013). - ISSN 0378-4290 - p. 106 - 118.
    pennisetum-typhoides s - tillering pearl-millet - nitrogen balances - simulating growth - central brazil - generic model - northern laos - burkina-faso - grain-yield - water-use
    Yield gaps of major food crops are wide under rainfed family agriculture in the tropics. Their magnitude and causes vary substantially across agro-ecological, demographic and market situations. Methods to assess yield gaps should cope with spatio-temporal variability of bio-physical conditions, management practices, and data scarcity under smallholder conditions. Particularly challenging is to determine the most relevant methods for estimating potential (Yp) and water-limited (Yw) yields against which actual yields (Ya) are compared. We assessed yield gaps of main staple rainfed crops across contrasting family farming systems in Senegal (millet, subsistence oriented systems), central Brazil (maize, market oriented systems) and Vietnam (maize, market oriented systems and upland rice, subsistence oriented systems). In each region, actual aboveground biomass, Ya and yield components were measured over 2–3 agricultural seasons in a network of farmers’ fields, covering the diversity of soils and farmers’ management practices. Yp and Yw were calculated using a simple ad hoc crop simulation model (potential yield estimator, PYE) that was calibrated for each situation with observed and secondary data. Maize yields measured on farmers’ fields were on average relatively high in market oriented systems, but extremely variable (4.14 ± 1.72 Mg ha-1). In contrast yields of crops of subsistence oriented systems were very low (0.80 ± 0.54 Mg ha-1 and 0.80 ± 0.47 Mg ha-1 for millet and upland rice, respectively). Ya - Yp was 0.15 for millet in Senegal, 0.33 for upland rice in Vietnam, 0.26 for maize in Vietnam, and 0.46 for maize in Brazil. In Vietnam, there was little difference between Yw and Yp suggesting a low incidence of water constraints. The gap between Ya and Yw was equal to (millet in Senegal) or twice (maize in Vietnam and Brazil) the difference between Yw and Yp, indicating that yield gaps depend strongly on factors other than global radiation, temperature, rainfall and soil water holding capacity. Previous studies in the case study areas showed that the main causes of yield gaps were poor soil fertility and weed infestation related to the inability of farmers to access chemical inputs. Simple methods to estimate Yw and Yp, such as the values at the 90th percentile of Ya, or a bilinear boundary function fitted between seasonal rainfall and the best farmers’ yield both led to strongly underestimated yield gaps. Yw and Yp estimated with a crop simulation model appeared to be more accurate, even in situations of relative scarcity of field data to calibrate cultivar-specific model parameters.
    Social-ecological and regional adaption of agrobiodiversity management across a global set of research regions
    Jackson, L.E. ; Pulleman, M.M. ; Brussaard, L. ; Bawa, K. ; Brown, G.G. ; Cardoso, I.M. ; Ruiter, P.C. de; Garcia-Barrios, L.E. ; Hollander, A.D. ; Lavelle, P. ; Ouedraogo, E. ; Pascual, U. ; Setty, S. ; Smukler, S.M. ; Tscharntke, T. ; Noordwijk, M. van - \ 2012
    Global environmental change : human and policy dimensions 22 (2012)3. - ISSN 0959-3780 - p. 623 - 639.
    atlantic rain-forest - agricultural intensification - biodiversity conservation - ecosystem services - environmental services - commodity production - production systems - central plateau - burkina-faso - landscape
    To examine management options for biodiversity in agricultural landscapes, eight research regions were classified into social-ecological domains, using a dataset of indicators of livelihood resources, i.e., capital assets. Potential interventions for biodiversity-based agriculture were then compared among landscapes and domains. The approach combined literature review with expert judgment by researchers working in each landscape. Each landscape was described for land use, rural livelihoods and attitudes of social actors toward biodiversity and intensification of agriculture. Principal components analysis of 40 indicators of natural, human, social, financial and physical capital for the eight landscapes showed a loss of biodiversity associated with high-input agricultural intensification. High levels of natural capital (e.g. indicators of wildland biodiversity conservation and agrobiodiversity for human needs) were positively associated with indicators of human capital, including knowledge of the flora and fauna and knowledge sharing among farmers. Three social-ecological domains were identified across the eight landscapes (Tropical Agriculture-Forest Matrix, Tropical Degrading Agroecosystem, and Temperate High-Input Commodity Agriculture) using hierarchical clustering of the indicator values. Each domain shared a set of interventions for biodiversity-based agriculture and ecological intensification that could also increase food security in the impoverished landscapes. Implementation of interventions differed greatly among the landscapes, e.g. financial capital for new farming practices in the Intensive Agriculture domain vs. developing market value chains in the other domains. This exploratory study suggests that indicators of knowledge systems should receive greater emphasis in the monitoring of biodiversity and ecosystem services, and that inventories of assets at the landscape level can inform adaptive management of agrobiodiversity-based interventions
    To tie or not to tie ridges for water conservation in Rift Valley drylands of Ethiopia
    Temesgen, B.B. ; Stroosnijder, L. - \ 2012
    Soil & Tillage Research 124 (2012). - ISSN 0167-1987 - p. 83 - 94.
    simulate yield response - fao crop model - northern ethiopia - use efficiency - burkina-faso - east-africa - tillage - maize - soil - aquacrop
    The Rift Valley drylands of Ethiopia are characterized by sandy loam soils that have poor fertility and unreliable rainfall conditions. The aim of this study was to examine the potential benefit of rainwater harvesting by tied-ridges and improved soil fertility on maize productivity through field experimentation and simulation with the FAO's AquaCrop model. The effect of tied-ridges with and without manure on maize yield at smallholder farms was studied during the years 2009 (very dry, 96% probability of exceedance) and 2010 (normal year, 46% probability of exceedance). During a normal rainfall, the mean yield of maize grain was 4.0 Mg ha(-1) when tied-ridges were applied in combination with manure (at 4.5 Mg ha(-1) rate); 3.4 Mg ha(-1) when tied-ridges were applied without manure; 3.5 Mg ha(-1) when traditional tillage was applied in combination with manure; and 2.7 Mg ha(-1) when traditional tillage was applied without manure. Long-term simulations with the FAO's AquaCrop showed that the root zone soil water may exceed field capacity for consecutive days during above average rainfall seasons in the shallow sandy loams. The question thus is when to tie or not to tie ridges. Therefore, upon proper calibration of the FAO's AquaCrop model, the effect of tied-ridges and improved soil fertility was simulated in response to different amounts of seasonal rainfall, number of rainfall days and sowing times. Simulations revealed that, during below average rainfall seasons (280-330 mm), tied-ridges are more effective at improving crop yields than enhancing the fertility level of the soil. But during above average rainfall seasons, the rainwater that is held in tied-ridges can be more effectively utilised when the current fertility level of the soil is improved. The simulated rainwater use efficiency of maize was 6.1-6.5 kg ha(-1) mm(-1) for traditional tillage without any fertiliser, 6.8-7.3 kg ha(-1) mm(-1) for tied-ridges without any fertiliser and 11.0-12.9 kg ha(-1) mm(-1) for tied-ridges with optimum fertiliser (96% soil fertility level). It is, therefore, concluded that combined use of tied-ridges and farmyard manure can enhance maize yield under wide range of rainfall conditions (annual rainfall ranging from 280 mm to 680 mm). The Maresha-modified ridger used in this study can be popularized among Ethiopian farmers due to its simplicity and effectiveness. (C) 2012 Elsevier B.V. All rights reserved.
    Land-use and biodiversity in unprotected landscapes : the case of non-cultivated plant use and management by rural communities in Benin and Togo
    Rodenburg, J. ; Both, J. ; Koppen, C.S.A. van; Heitkonig, I.M.A. ; Kiepe, P. - \ 2012
    Society & Natural Resources 25 (2012)12. - ISSN 0894-1920 - p. 1221 - 1240.
    tropical forest conservation - resource-management - indigenous knowledge - medicinal-plants - burkina-faso - west-africa - vegetation - perceptions - areas - cultivation
    To contribute to the development of strategies for sustainable agricultural land use and biodiversity conservation in landscapes without formal protection status, we investigated the local use and management of noncultivated plants as important ecosystem functions of inland valleys in south Benin and Togo, and local perceptions on changes in plant biodiversity and causes for these changes. Local users of noncultivated plants perceived agriculture and construction as major factors contributing to the reduction of (noncultivated) plant biodiversity. However, they also collect many useful species from agricultural fields and the village. A small community forest reserve and a 2-ha community garden were the only organized forms of conservation management. Observed ad hoc conservation initiatives were selective harvesting of plant parts, preserving trees during land clearing, and allowing useful weed species in the field. Future development and conservation efforts in unprotected landscapes with multiple ecosystem functions should acknowledge knowledge, interests, and needs of local communities.
    Current and future nitrous oxide emissions from African agriculture
    Hickman, J.E. ; Havlikova, M. ; Kroeze, C. ; Palm, C.A. - \ 2011
    Current Opinion in Environmental Sustainability 3 (2011)5. - ISSN 1877-3435 - p. 370 - 378.
    crop-livestock systems - nitric-oxide - millennium villages - natural savanna - soil emissions - burkina-faso - n2o - kenya - fertilizer - database
    Most emission estimates of the greenhouse gas nitrous oxide (N2O) from African agriculture at a continental scale are based on emission factors, such as those developed by the IPCC Guidelines. Here we present estimates from Africa from the EDGAR database, which is derived from the IPCC emission factors. Resulting estimates indicate that N2O emissions from agriculture represented 42% of total emissions from Africa (though that rises to 71% if all savannah and grassland burning is included), or roughly 6% of global anthropogenic N2O emissions (or 11% including burning). Emissions from African agriculture are dominated by grazing livestock; 74% of agricultural N2O excluding biomass burning was from paddocks, ranges, and pasture. Direct soil emissions represent 15% of agricultural emissions; substantial changes in direct emissions from North Africa helped drive a 47% continental increase in direct soil emissions from 1970 to 2005. Future trends based on the Millennium Ecosystem Assessment scenarios indicate that agricultural N2O emissions may double in Africa by 2050 from 2000 levels. Any regional or continental estimates for Africa are, however, necessarily limited by a paucity of direct measurements of emissions in sub-Saharan agro-ecosystems, and the heavy reliance on emission factors and other default assumptions about nitrogen cycling in African agriculture. In particular, a better understanding of livestock-related N inputs and N2O emissions will help improve regional and continental estimates. As fertilizer use increases in sub-Saharan Africa, emission estimates should consider several unusual elements of African agriculture: farmer practices that differ fundamentally from that of large scale farms, the long history of N depletion from agricultural soils, seasonal emission pulses, and emission factors that vary with the amount of N added.
    Host-parasite dynamics of Sorghum bicolor and Striga hermonthica - The influence of soil organic matter amendments of different C:N ratio
    Ayongwa, G.C. ; Stomph, T.J. ; Kuyper, T.W. - \ 2011
    Crop Protection 30 (2011)12. - ISSN 0261-2194 - p. 1613 - 1622.
    fertility management - western kenya - burkina-faso - infestation - fallow - maize - sahel - dissemination - decomposition - systems
    The effect of organic amendments on the interactions between Striga hermonthica and a sorghum host was studied in a field experiment during three cropping seasons, following a three-factorial design with (i) bare fallow versus continuous cropping, (ii) two Strigahermonthica infection levels and (iii) five organic matter levels, a single inorganic fertiliser treatment of 120 kg N ha-1 and a control. The effects of two different cotton by-products and their mixtures on sorghum yield were well described by their N-mineralisation pattern. The impact of organic amendments in the sorghum production system was directly related to N-mineralisation in the three cropping seasons. There was an increasing negative effect of organic matter on S. hermonthica as the quality of the applied material increased. The emerged numbers of S. hermonthica were well described by N-release after one month, while S. hermonthica biomass and sorghum biomass were well described by N-release after three months. As a stand-alone measure, addition of low-quality organic matter is disadvantageous in cropping systems with high S. hermonthica seed densities, as it does not improve sorghum performance compared to no addition of organic matter, while S. hermonthica numbers increase. Implications for integrated soil fertility and S. hermonthica management under different infection levels of S. hermonthica are discussed
    Beneficial effects of wind erosion: Concepts measurements and modeling
    Poortinga, A. ; Visser, S.M. ; Riksen, M.J.P.M. ; Stroosnijder, L. - \ 2011
    Aeolian Research 3 (2011)2. - ISSN 1875-9637 - p. 81 - 86.
    aeolian sand transport - inland drift-sand - burkina-faso - farmers perceptions - prediction system - water erosion - soil-erosion - dune - sahel - beach
    Exploring the diversity of urban and peri-urban agricultural systems in Sudano-Sahelian West Africa: An attempt towards a regional typology
    Dossa, L.C. ; Abdulkadir, A. ; Amadou, H. ; Sangare, S. ; Schlecht, E. - \ 2011
    Landscape and Urban Planning 102 (2011)3. - ISSN 0169-2046 - p. 197 - 206.
    principal-components-analysis - farming systems - milk-production - burkina-faso - management - opportunities - classification - potentials - algorithm - countries
    Developing appropriate and innovative technologies and policies to respond to the challenges that urban and peri-urban agriculture (UPA) faces in West Africa requires a better understanding of the existing production systems. Although there is an increasing recognition of the importance of UPA in the region, its extent, forms and related practices may vary across countries and cities because of different socio-economic conditions and urbanization patterns. A systematic classification of the regional UPA systems is lacking but is necessary to allow for meaningful comparisons between cities and avoid misleading generalizations. The purpose of this study was to develop a typology of UPA households across three selected West African cities. Survey data from 318 UPA households (Kano: 99, Bobo Dioulasso: 111, Sikasso: 108) were submitted to principal components analysis for categorical variables (CATPCA). Next, the Two-Step cluster method was used to classify the households using object scores obtained from the CATPCA. Diversification of farm activities, farm resource endowment and production orientation were the major discriminating variables. In each city, four distinct UPA systems were identified, of which three were common to Kano, Bobo Dioulasso and Sikasso: commercial gardening plus field crops and livestock (59%, 18%, and 37%), commercial livestock plus subsistence field cropping (14%, 41%, and 7%), and commercial gardening plus semi-commercial field cropping (14%, 28%, and 30%). The fourth group was different at each location and was characterized as follows: commercial gardening plus semi-commercial livestock in Kano (13%), commercial field cropping in Bobo Dioulasso (13%) and commercial gardening in Sikasso (26%).
    Agriculture and food security in selected countries in Sub-Sahara Africa: diversity in trends and opportunities
    Graaff, J. de; Kessler, A. ; Nibbering, J.W. - \ 2011
    Food Security (2011). - ISSN 1876-4517 - 26 p.
    green-revolution - land management - burkina-faso - productivity - malawi
    The World Food Summit in 1996 set the goal of reducing by half the numbers of malnourished people in the world by 2015. It is unlikely that this will be reached, and particularly not in Sub-Saharan Africa (SSA). Food imports in SSA have increased in the past forty years, since domestic production could not keep up with population growth. Several studies have reported about this stagnating food production in SSA. However, this region encompasses a large number of countries, with a great variety of agro-ecological zones and large differences in land, labour and other resources. The objectives of this paper are to analyse agricultural production and food security in eight countries in Sub-Saharan Africa over the past 40 years, and to investigate to what extent these countries have followed different agricultural development pathways and are faced with different constraints. The analysis is largely based on statistical data, mainly from FAO, and on other information from various national and international sources. It shows that some of these countries have struggled to achieve and maintain overall national food security, while others have been able to achieve more than that and increased production at a faster rate than population growth. It subsequently analyzes major development constraints, with regard to labour, land and water, and institutions, pinpoints certain positive developments that have taken place in some of the countries and looks at opportunities for the respective countries to improve their food situation. One of its conclusions is that more attention should be paid to country specific constraints and opportunities
    Agriculture, livelihoods and climate change in the West African Sahel
    Sissoko, K. ; Keulen, H. van; Verhagen, A. ; Tekken, V. ; Battaglini, A. - \ 2011
    Regional Environmental Change 11 (2011)suppl. 1. - ISSN 1436-3798 - p. S119 - S125.
    burkina-faso - level - rainfall - drought - 20th-century - dynamics - farm
    The West African Sahel is a harsh environment stressed by a fast-growing population and increasing pressure on the scarce natural resources. Agriculture is the main source of livelihood of the majority of the people living in the area. Increases in temperature and/or modifications in rainfall quantities and distribution will substantially impact on the natural resource on which agriculture depends. The vulnerability of livelihoods based on agriculture is increased and most likely exacerbate and accelerate the current ‘downward spiral’ of underdevelopment, poverty and environmental degradation. Notably, droughts, a short rainy season and/or very low rainfall will be felt by current systems. To cope with the difficult climatic situation, farm households have developed a range of strategies including selling of animals and on-farm diversification or specialization. At regional level, early warning systems including an operational agro-meteorological information system already provide farmers with crucial information. Substantial political, institutional and financial efforts at national and international level are indispensable for the sustenance of millions of lives. In terms of development, priority needs to be given to adaptation and implementation of comprehensive programs on water management and irrigation, desertification control, development of alternative sources of energy and the promotion of sustainable agricultural practices by farmers
    Rich nutrition from the poorest - Cereal fermentations in Africa and Asia
    Nout, M.J.R. - \ 2009
    Food Microbiology 26 (2009)7. - ISSN 0740-0020 - p. 685 - 692.
    lactic-acid bacteria - millet pennisetum-glaucum - maize dough fermentation - burkina-faso - ben-saalga - natural fermentation - process combinations - kenkey production - starter culture - energy density
    Cereal fermentations in Africa and Asia involve mainly the processing of maize, rice, sorghum and the millets. Lactic acid bacteria (Lactobacillus, Pediococcus), Enterobacter spp., yeasts (Candida, Debaryomyces, Endomycopsis, Hansenula, Pichia, Saccharomyces and Trichosporon spp.) and filamentous fungi (Amylomyces, Aspergillus, Mucor, and Rhizopus spp.) contribute to desirable modifications of taste, flavour, acidity, digestibility, and texture in non-alcoholic beverages (e.g., uji, and ben-saalga), porridges (e.g., mawè) and cooked gels (e.g., kenkey, idli, and mifen). In addition, alcoholic beverages (beers such as tchoukoutou and jnard; and spirits e.g. jiu) are obtained using malt, or using amylolytic mixed microbial starter cultures as generators of fermentable substrates. Wet processing, marketing of multi-purpose intermediate products, co-fermentation for texture and nutrition, and mixed culture fermentations as practiced in indigenous fermentation processes are of interest for industrial innovation and for better control of natural mixed culture fermentation systems. On the other hand, the nutritional properties of traditional cereal fermented products can be enhanced by increasing their nutrient and energy density, as well as by increasing their mineral status by combining mineral fortification and dephytinization
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