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The promotion of composting for urban agriculture has great potential to mitigate global climate change. Composting reduces the uncontrolled decomposition of organic waste that contributes to green-house gas emissions and its use in agriculture helps sequester carbon from the atmosphere. Furthermore, urban agriculture shortens food chains, reduces transportation needs, and contributes to food security.
This project aims to examine the following issues:
The project’s interdisciplinary approach assesses compost-induced improvements of local soils and considers actors, social practices and relationships, institutions and changing material properties along the entire food-waste-farming chain starting – from food consumption and waste production, waste management and composting, to compost use in urban farming. To do so, the research team relies largely on interviews and focus groups, but also on laboratory analyses.
Furthermore, the project not only seeks to engage with key stakeholders in both countries, including urban farmers, planners and policymakers, but also to facilitate knowledge exchange across geographical contexts with the goal to develop policy recommendations for localizing and closing the food-waste-farming cycle in different contexts.
Assuming that closing the food-waste-farming cycle has great potential to contribute to climate change mitigation, this interdisciplinary study sought to identify the opportunities and obstacles for urban agriculture using compost from kitchen waste in Dschang (Cameroon) and Lausanne (Switzerland). We found that the widespread knowledge and practice of urban farming and the abundance of compostable waste in Dschang hold promise for the adoption of compost-based urban agriculture but is severely constrained by deficient waste segregation at source and by inappropriate government policies. In Lausanne, by contrast, urban farming is limited, and compost from kitchen waste is scarce because of the adoption of complex waste treatment technologies (i.e., biomethanation). Nevertheless, the rise in urban gardening offers some prospect for closing the cycle through compost-making at the individual and community levels.
This comparative study focuses on two diametrically different contexts of urban agriculture: in Dschang, in Cameroon, as subsistence agriculture and in Lausanne, in Switzerland, as recreational gardening. The objectives are to highlight and compare the fertility and the quality of soils within the two cities, as well as to analyze the quality of composts.
Results highlight important differences between the two cities: a) Contamination by heavy trace metals and microplastics is greater in Lausanne than in Dschang. b) Soils have good fertility in both cities, but nutrient contents vary. c) The parent material, which is very different between the two countries, influences the levels of nutrients and trace elements in soils and composts.
Several studies have been looking at how food waste is generated and how consumers can reduce volumes. So far, very little is said about the kitchen waste segregation practices that stand before the municipal processing. Yet, organic waste requires specific recovery process toward the circular economy from kitchen to farm. This article focuses on what is (in)visible at the level of households as a conceptual lever for uncovering opportunities for closing the food-waste-farming cycle. Based on series of interviews and survey with diverse households and with experts from the waste management service in Lausanne, a social practice theory analysis has evidenced a high potential in implementing organic waste separation for composting when making practices visible. This paper show that food waste needs to become publicised and localized in the city and seizing the opportunity for a more community level approach to composting and urban gardening. We argue that opportunities for stepping up the existing food waste sorting practices by the residents are anchored within the incentives for bin bags tax as well as material arrangements and educational schemes that shift meanings and deliver new competencies.
Waste management is pivotal in shaping the urban landscape as urbanization in Africa is spreading. This paper shows that in small and medium-sized cities in Africa, there is a growing interest in sorting household waste at the individual level and that this trend should be capitalized on by municipalities for better-integrated waste management. Using a mixed research method, this paper explores emerging practices and constraints for organic waste segregation by households and restaurants in Dschang. Results are shaped with a Situated Urban Political Ecological (SUPE) and Social Practice Theory (SPT) dimensions of everyday practice and power relations. Findings revealed that households sort waste either to feed animals (81.8%) or for composting (18.2%). Restaurants (59%) provide organic waste to waste pickers and receive compensation for their time and efforts. However, the complex and ambiguous legal framework and poor enforcement of existing regulations have acted as a disincentive to waste sorting at the source. It is found that waste sorting is affected by a lack of appropriate dustbins, space in kitchens, and institutional limitations that disfavor practices such as composting and composting use. The urban metabolism of waste presents positive and negative externalities resulting from material flows and the interaction of actors. Complex power relations arise from socio-cultural and gender differences among household members and conflicts between waste handlers, private associations, and the municipality. Linking SUPE and SPT, this paper articulates that improving on existing practices can help implement source segregation.
René Véron
Coordinator
University of Lausanne
Marlyne Sahakian
Co-Coordinator
University of Geneva
Rolande Christelle Makamté Kakeu-Tardy
Principal Member
University of Lausanne
Research Assistant
Principal Member
University of Geneva
Yemmafouo Aristide
Principal Member
University of Dschang, Cameroon
Moye Eric Kongnso
Principal Member
University of Dschang, Cameroon
Jean Grandjux
Principal Member
Urbaplan
To be Named
Principal Member
Urbaplan
Sagne Moumbe Joel
Principal Member
Environment – Research – Action Cameroon
Stephanie Grand
Associated Member
University of Lausanne
To be Named
Associated Member
International Association of Francophone Mayors
Swiss Network for
International Studies