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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    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.
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