Urban agriculture in Dar es Salaam, Tanzania: A systematic review of practices, challenges and sustainability

Urban agriculture (UA) is increasingly recognized as vital to food production, livelihoods, and food security in fast-urbanizing African cities. However, policy-making remains challenged by fragmented and dispersed evidence, particularly at the city level. This systematic review addresses this gap for Dar es Salaam, Tanzania, guided by the central research question: What does existing peer-reviewed and grey literature from 1990 to 2024 reveal about UA practices, scale, socio-economic contributions, health and environmental impacts, governance constraints, and related policy implications? A systematic search of Web of Science, Scopus and Google Scholar, supplemented by grey literature, identified 42 studies meeting the PRISMA 2020 criteria. Key findings report that 36,000–60,000 UA households cultivate 1800–6000 ha annually, supplying 90% of city vegetables. UA provides 20-70% of household income and employs over 100,000 people, yet 85–95% of farmers lack secure land tenure, 78% of vegetable samples exceed WHO E. coli limits, and 90% of produce is sold informally with high post-harvest losses (20-40%). Major research gaps persist in climate adaptation, value chain development, and nutrition. To achieve sustainable, food-secure UA in Dar es Salaam, urgent policy actions are needed: formalize land tenure, upgrade market infrastructure, strengthen water quality governance, and enhance institutional support for producers and vendors.