Browsing by Author "Luedeling, Eike"

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    Crop diversity in homegardens of southwest Uganda and its importance for rural livelihoods
    (Agriculture and Human Values, 2018) Whitney, Cory W.; Luedeling, Eike; Tabuti, John R. S.; Nyamukuru, Antonia; Hense, Oliver; Gebauer, Jens; Kehlenbeck, Katja
    Homegardens are traditional food systems that have been adapted over generations to fit local cultural and ecological conditions. They provide a year-round diversity of nutritious foods for smallholder farming communities in many regions of the tropics and subtropics. In southwestern Uganda, homegardens are the primary source of food, providing a diverse diet for rural marginalized poor. However, national agricultural development plans as well as economic and social pressures threaten the functioning of these homegardens. The implications of these threats are difficult to evaluate, because the structure and functions of the homegardens are not well understood. The aim of the study was to identify patterns and influencing factors in the diversity of homegardens by documenting the floristic diversity and its interactions with spatial, environmental and socio-economic factors. A geographically and socially focused assessment of floristic diversity in 102 randomly selected homegardens in three districts of southwest Uganda was conducted along a deforestation gradient following a human ecology conceptual framework and testing multiple quantitative hypotheses regarding the above mentioned factors. A merged mixed-method approach was followed to provide context and feedback regarding quantitative findings. Results show a high total richness of 209 (mean 26.8 per homegarden) crop species (excluding weeds and ornamentals) dominated by food species, which constituted 96 percent of individuals and 44 percent of all species. Forest-edge homegardens maintained higher plant diversity compared to homegardens in deforested areas and near degraded wetlands. Multiple linear regression models indicated elevation, location, homegarden size, distance to market, additional land ownership (outside the homegarden) and livestock ownership as significant predictors of crop diversity. Cluster analysis of species densities revealed four garden types: ‘diverse tree gardens’, ‘small forest-edge gardens’, ‘large, old, species-rich gardens’, and ‘large, annual-dominated herb gardens’, with 98% correct classification. Location, elevation, and garden size were also important determinants in the cluster assignment. We conclude that the diversity of the studied homegardens may be changing as part of adaptive traditional practices and in response to external drivers. The identified patterns illustrate the importance of homegardens for rural livelihoods and may offer some ways to support farmers to maintain these systems as relevant mechanisms for development in Uganda.
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    Homegardens and the future of food and nutrition security in southwest Uganda
    (Agricultural Systems, 2017) Tabuti, John R.S.; Luedeling, Eike; Whitney, Cory W. a Yehf, Jens Gebauera, Eike Luedelingb; Hensel, Oliver; Yeh, Ching-Hua; Gebauer, Jens
    Governments around the world seek to create programs that will support sustainable agriculture and achieve food security, yet they are faced with uncertainty, system complexity and data scarcity when making such choices. We propose decision modeling as an innovative approach to help meet these challenges and offer a case study to show the effectiveness of the tool. We use decision analysis tools to model the possible nutrition-related outcomes of the Ugandan government's long term agricultural development plan termed ‘Vision 2040’. The analysis indicates potential shifts in household nutritional contributions through the comparison of the current small-scale diverse systems and the envisioned industrial agricultural systems that may replace them. A Monte Carlo simulation revealed that Vision 2040 plans outperform homegardens in terms of energy and some macronutrients, yet homegardens are likely to be better at producing key vitamins and micronutrients, such as Vitamin A. Value of information calculations applied to Monte Carlo outputs further revealed that gathering more data on the annual yields and nutrient contents of staples, pulses, vegetables, and fruits could improve certainty about the nutrition contribution of both scenarios. We conclude that the development of Uganda's agricultural sector should consider the role that agrobiodiversity in the current small-scale agricultural systems plays in national food and nutrition security. Any changes according to Vision 2040 should also include farmers' voices and current crop management systems as guides for a sustainable food supply in the region. This modeling approach may be a tool for governments to consider agricultural policy implications, especially given the data scarcity and agricultural variability in regions such as East Africa.
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    Probabilistic decision tools for determining impacts of agricultural development policy on household nutrition
    (Earth's Future, 2018) Whitney, Cory W.; Lanzanova, Denis; Muchiri, Caroline; Shepherd, Keith D.; Rosenstock, Todd S.; Krawinkel, Michael; Tabuti, John R. S.; Luedeling, Eike
    Governments around the world have agreed to end hunger and food insecurity and to improve global nutrition, largely through changes to agriculture and food systems. However, they are faced with a lot of uncertainty when making policy decisions, since any agricultural changes will influence social and biophysical systems, which could yield either positive or negative nutrition outcomes. We outline a holistic probability modeling approach with Bayesian Network (BN) models for nutritional impacts resulting from agricultural development policy. The approach includes the elicitation of expert knowledge for impact model development, including sensitivity analysis and value of information calculations. It aims at a generalizable methodology that can be applied in a wide range of contexts. To showcase this approach, we develop an impact model of Vision 2040, Uganda’s development strategy, which, among other objectives, seeks to transform the country’s agricultural landscape from traditional systems to large-scale commercial agriculture. Model results suggest that Vision 2040 is likely to have negative outcomes for the rural livelihoods it intends to support; it may have no appreciable influence on household hunger but, by influencing preferences for and access to quality nutritional foods, may increase the prevalence of micronutrient deficiency. The results highlight the trade offs that must be negotiated when making decisions regarding agriculture for nutrition, and the capacity of BNs to make these trade offs explicit. The work illustrates the value of BNs for supporting evidence based agricultural development decisions.
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    The Role of Homegardens for Food and Nutrition Security in Uganda
    (Human Ecology, 2018) Whitney, Cory William; Luedeling, Eike; Hensel, Oliver; Tabuti, John R. S.; Krawinke, Michael; Gebauer, Jens; Kehlenbeck, Katja
    The contribution of homegardens to the food and nutrition security of rural farmers has rarely been explored empirically. Our study assesses the influence of homegarden agrobiodiversity, production system parameters, and socioeconomic factors on household dietary diversity and anthropometric conditions in southwest Uganda. Plant inventories of 102 homegardens were followed by two 24-h recalls (n = 589) and anthropometric measurements (n = 325) of household members, as well as household food insecurity questionnaires (n = 95). Regression models explained between 16 and 50% of variance in dietary diversity and between 21 and 75% in anthropometric measurements. Results indicate that supporting diverse homegarden systems can in part reduce food insecurity in Uganda. We conclude with recommendations for further strengthening the role of homegardens in improving dietary and anthropometric outcomes.