Research & reports

Human Sciences Research Council · Figshare · South Africa

A 2025 study from South Africa's Western Cape used propensity score matching on data from 220 households — those participating in Department of Agriculture-funded backyard garden projects plus a control group — to assess urban agriculture's contribution to household food security. Households engaged in urban agriculture benefited from greater dietary diversity and income from selling produce, but the study found no significant positive contribution of urban agriculture to food security.

Rueda, Ximena · Socio-Environmental Systems Modeling · Africa

A 2025 comparative analysis examines agricultural, economic, and biodiversity policy across Cameroon, Kenya, and Colombia in the context of agricultural expansion, using discourse analysis of policy documents via the Nature Futures Framework and Life Frames Framework, an evaluation of budgets allocated to major agricultural and biodiversity policies, and stakeholder interviews. It finds a shared struggle across all three countries to harmonize agricultural development with biodiversity conservation despite differing institutional capacities, historical pathways, and sociocultural contexts, with agriculture continuing to dominate policy agendas and resource allocation even as recognition of biodiversity's importance grows. Nature is framed primarily in instrumental terms, most strongly so in Colombia's utilitarian "Nature for Society" orientation, with intrinsic and relational values rooted in Indigenous cosmologies weakly reflected in implementation; funding for biodiversity-related ministries remains minimal relative to agriculture in all three countries — Kenya's environmental budget rarely exceeds 0.3% of national expenditure, with Cameroon showing similar disparities and Colombia's allocations continuing to favor agricultural expansion — and institutional fragmentation further undermines this governance.

Mwangi Kamau, Wanjiku Otieno · International Journal of Veterinary Sciences and Animal Husbandry · Kenya

This study characterized the physicochemical quality of untreated wastewater from three small-scale slaughterhouses on the outskirts of Nairobi, Kenya, and measured its effect on soil microbiology at 0, 50, and 200 meters from the discharge point during both wet and dry seasons. Wastewater biochemical oxygen demand (BOD5) ranged from 1,840 to 2,620 mg/L and chemical oxygen demand (COD) from 3,410 to 4,870 mg/L, exceeding Kenyan discharge standards by 6- to 10-fold. Total bacterial counts in soil at the discharge point were 2.7 times higher than at 200 m (p<0.001), and total coliform counts were 4.1 times higher (p<0.001). The Shannon-Wiener diversity index rose significantly with distance from the discharge point (1.42±0.14 at 0 m vs. 2.34±0.18 at 200 m; p<0.001), indicating that wastewater irrigation selects for a less diverse, coliform-dominated soil microbial community. Seasonal variation was significant for BOD5 and coliform loading but not for the diversity index.

Vidjinnagni Vinasse Ametooyona Azagoun, Kossi Komi, Djigbo Félicien Badou, Expédit Vissin, Komi Sélom Klassou · Geographies · Africa

Drawing on socio-economic, techno-agronomic, and perceptual data collected from 369 growers in the Grand Nokoué region of Benin, this study combined multiple correspondence analysis (MCA) with ascending hierarchical analysis (AHA), confirmed by K-means partitioning, to identify profiles of climatic vulnerability among urban market gardeners. Three distinct vulnerability groups were identified, differing in socioeconomic, technical, and territorial characteristics and in their exposure to flooding, drought, and dry spells. The most vulnerable farmers were disproportionately young women with low incomes, limited access to land, and reliance on manual irrigation in flood-prone areas. The findings point to an uneven distribution of adaptive capacity and a need for public policies tailored to strengthen the resilience of small-scale, low-income, and land-insecure urban farmers who are exposed to these climate-related risks.

Valentine Opanga · Urban Political Ecology · Kenya

A study examines how green urbanism is imagined, politicised and contested in two informal settlements in Nairobi, Kenya, Korogocho and Pumwani-Majengo, using a mixed-methods approach combining Feminist Urban Political Ecology, Postcolonial Urbanism and Travelling Models, drawing on 45 semi-structured interviews, six focus group discussions and a review of policy documents. It shows that international greening agendas are selectively interpreted, reworked or resisted rather than adopted as a unified global sustainability narrative. Findings reveal that state-led greening initiatives, even when aligned with global frameworks, can reinforce spatial inequality, displace low-income residents and obscure colonial-era land injustices. At the same time, grassroots actors engage in context-specific greening practices such as urban farming and dumpsite reclamation driven by survival and care, representing forms of environmental agency that challenge dominant models.

Byamungu Lincoln Zabuloni, Maxwell Mudhara, Joyce Chitja · Food and Energy Security · South Africa

A study assessing the impact of home- and community-garden programs on household food security status in uMzumbe Local Municipality, KwaZulu-Natal, South Africa, using random and purposive sampling to survey 223 respondents with a structured questionnaire and a Tobit regression model to examine determinants. Total income (p<0.001), extension services (p<0.01), credit access (p<0.05), age, farm size (p<0.01) and education level (p<0.05) positively affected food security status, while household size (p<0.001), home gardens (p<0.01) and community gardens (p<0.01) negatively affected it. The study concludes that implementing home and community garden programs alone was not enough to improve households' food security status in uMzumbe Municipality.

Ermias Debie · City and Environment Interactions · Ethiopia

A study in Bahir Dar, Ethiopia examined the integration of urban agriculture (UA) and green infrastructure (GI) through surveys and interviews with 99 stakeholders, supplemented by participatory observation. The main barriers to integration, based on multiple-response data, were a lack of supportive policies and regulatory frameworks (87%), limited awareness (57%), and space constraints (51%). Multicriteria decision analysis ranked integrated practices as the most effective strategy (score 16.81), followed by edible tree planting at garden centers (16.18), small gardens (13.83), and fence-edge greening (11.46). Structural equation modeling identified thermal regulation and access to fresh food as critical factors for planning sustainable urban systems.

Abubakar Mohd Habu, Ali Sanusi Hassan, Adeniyi Olarewaju Adeleye, Michael Edet Nkereuwem, Ijanu Emmanuel Madu, Garba Barde Bate, Olukemi Adeleye, Usman Mohammed Isah · Biological Environment and Pollution · Nigeria

This study assessed heavy-metal accumulation and non-carcinogenic health risks in commonly consumed leafy vegetables -- lettuce, spinach, and cabbage -- cultivated with wastewater in Zawaciki, Kano State, Nigeria. Vegetable and rhizospheric soil samples were analyzed for cadmium, lead, chromium, nickel, zinc, and copper using atomic absorption spectrophotometry, and bioaccumulation factors (BAFs) were calculated as the ratio of metal levels in plant tissue to soil. Metal concentrations varied significantly across the vegetables (p < 0.05), with lead in lettuce leaves exceeding the FAO/WHO permissible limit by more than 120 times; chromium in cabbage reached 32.22 mg/kg, while lettuce showed elevated zinc (19.83 mg/kg) and copper (9.26 mg/kg). Hazard-quotient risk assessments found HQs for chromium and lead both exceeding 1, and the cumulative hazard index exceeded 1 for all vegetables, reaching its highest value of 18.861 in lettuce.

Getachew Demissie Desta, Zeleke Gonfa Wordofa · International Review for Spatial Planning and Sustainable Development · Ethiopia

A study of the rate and direction of spatial expansion of Robe Town, Ethiopia, into surrounding rural kebeles, and its effect on the tenure security of peri-urban landholders. It combined socioeconomic data from 202 sampled household heads with spatial data from Landsat images taken in 1987, 2002, and 2020. The town grew annually by 18.6% (1984–1994), 11.3% (1994–2007), and 9.3% (2007–2020), with its total area rising from 5.1 km² in 1984 to 80.2 km², a 40.9% overall increase. Over the 33-year period, built-up area expanded fastest southward, reaching 9.91 km from the town's mean center, and grew from 4.38 km² in 1987 to 27.9 km² in 2020; about 10.2 km² of farmland was converted to built-up land between 1987 and 2020. In peri-urban areas of Robe town, 48.9% of landowners lost around half of their farmland, leaving peri-urban landowners feeling insecure about their tenure due to fear of eviction and expropriation at minimal compensation.

Getinet, Abate · National Academic Digital Repository of Ethiopia · Ethiopia

A mixed-methods, cross-sectional descriptive study of urban agriculture in Gulele sub-city, Addis Ababa, Ethiopia, examining perceptions, opportunities, and challenges. It combined a survey of employees and farmers, in-depth interviews with farmers, key informants, and experts, and a focus group discussion with civil service employees. The study identified scarcity of urban farmland, scarcity of water for irrigating vegetables, and constraints on various agricultural inputs as core problems, alongside market accessibility issues for selling produce and limited transportation availability, even as vegetable consumption and demand among urban dwellers were rising and government policy treated urban agriculture as a current priority. It also found a negative social attitude among urban dwellers toward urban agriculture, who regard it as old-fashioned work and view urban farmers as backward and uneducated. The study concludes that the Addis Ababa City Administration's urban agriculture development sector needs to work with research institutions to address pest and insect problems and to improve vegetable yield per unit of land.

Ashagrie Gibtan, Wondwosen Abera, Mekuria Delelegn, Molla Maru, Adamu Emiru · Ochrana prírody Slovenska/Ekológia · Ethiopia

Land Use/Land Cover (LULC) dynamics were analyzed in four Ethiopian cities—Addis Ababa, Hawassa, Bahir Dar, and Adama—over 17 years from 2006 to 2022. SPOT 5 and Sentinel satellite imagery, key informant interviews, focus group discussions, and field observations were used. Findings revealed a rapid expansion of urban built-up areas, primarily at the expense of peri-urban horticultural lands, which has an adverse impact on the sustainability of urban agriculture.

Nolwazi Z. Khumalo, Melusi Sibanda, Lelethu Mdoda · Sustainability · Sub-Saharan Africa

A systematic review and bibliometric analysis examined the implications of climate-smart agriculture (CSA) practices and climate adaptation strategies for food and income security in urban Sub-Saharan Africa. The review found that CSA practices boost urban food production and income, but also recognized critical challenges and trade-offs requiring urban agriculture transformation.

Jeffrey Chiwuikem Chiaka, Gengyuan Liu, Hui Li, Wen Zhang, Mingwan Wu, Zhaoman Huo, F. Gonella · Environmental and Sustainability Indicators · Sub-Saharan Africa

This study evaluated land cover change and its drivers using spatial and statistical analysis in 22 designated protected areas (PAs) across the tropical coastal regions of sub-Saharan Africa. Results indicated that food production is prevalent in these protected areas regardless of their designation, and forest loss occurred in most PAs, suggesting weak conservation. Population density was the most significant driver of land cover change, and only 15 out of 22 protected areas showed an increase in their total ecosystem service value.

Ivica Petríková, Melvine Anyango Otieno, Gertrude Were, Mahmoud Eltholth, Ana Rodriguez‐Mateos, Seeromanie Harding, Victoria Hall Morán, Odipo Osano, Jennifer Cole · Food Security · Kenya

This study investigated the links between peri-urban households' engagement in agriculture, their dietary behavior, and their children's nutrition outcomes around Eldoret, Kenya. Survey data collected from 518 households indicated that peri-urban households involved in agriculture, particularly crop growing and sales, had more diverse and nutritious diets than non-engaged households. However, a significant improvement in children’s health outcomes in these households was observed only when coupled with improved water, sanitation, and hygiene conditions.

Arcadius Martinien Agassin Ahogle, Sammy Letema · Water International · Kenya (Nairobi)

This article examines the dynamics of irrigated urban agriculture (IUA) and its socio-technical arrangements in the Nairobi catchment, Kenya. The research identified five principal forms of IUA, differentiated by land size, water sources, technicality, actors, and market orientation. A critical finding is that city services do not provide hydraulic infrastructure or agricultural extension for IUA, and state agencies do not account for IUA practices, indicating a lack of governance support.

Epsar Philip Kopteer, Olakunle Rufus Oladosu, Samuel Adeyemi Samson, Jasini Ali Alwadood, Olaide Monsur Aderoju, Bose Adetutu Ogwurike, Michael Nnaemeka Ihenacho, James Adah John, Philip Okoh Amodu, Nkechinyere Gift Nwagwu, Chikodili Evans Ezurike, Kamila Abba Tukur, Augustine Abah Odeh, Sumaiyat Abdullahi Kpanja, Halimat Ifedolapo Oriola, Vivian Ibrahim, Udya Aniya, Elizabeth Rizga Jackson, Kikelomo Oluwabukola Adebo · World Journal of Advanced Research and Reviews · Nigeria (Jos)

This study investigated the economic impact of urban flooding on agricultural activities along the Dilimi River in Jos North LGA, Plateau State, Nigeria, using a 2021 satellite image and GIS analysis. The study found that loss of farmland, hunger and starvation, loss of properties, and high incidence of poverty were perceived as serious economic impacts of floods on farmers. Agricultural land use covered 2.82% of the study area.

Stefania Lovo, Samantha Rawlings · The World Bank Economic Review · Ghana, Nigeria

This study investigated the impact of e-waste dumping sites on neonatal and infant mortality, focusing on two major dumpsites in Ghana and Nigeria. Using a difference-in-differences approach, outcomes were compared for children born near and far from dumpsites before and after their creation. E-waste sites increased neonatal and and infant mortality for those living closer to the sites, with event studies suggesting effects emerge two to three years after site openings. There is suggestive evidence that contamination of water and of urban farming produce are among the drivers of the observed effects.

Hailekiros Tadesse Tekle, Desta Berhe Sbhatu, Gebreselema Gebreyohannes · H2Open Journal · Ethiopia (Mekelle)

A study in Hadnet district, Mekelle, Ethiopia, assessed heavy metal concentrations in wastewater, spring water, and three leafy vegetables (lettuce, spinach, cauliflower). Wastewater samples from four experimental sites exceeded permissible limits for 4 out of 10 heavy metals (Cd, Cr, Cu, Mn), and spring water from a comparison site also exceeded limits for 4 metals (Al, As, Cd, Cu). Leafy vegetables grown in the least contaminated experimental site showed high concentrations for 6-7 out of 10 heavy metals, with lettuce and spinach having elevated levels of As and Al, respectively. The study concluded that the wastewater used for irrigation is not safe, the farm soils may have accumulated significant heavy metals, and the cultivated vegetables are highly contaminated, necessitating regulation of wastewater use for irrigation.

Emmanuel Olatunbosun Benjamin, Abiola Adegoke, Gertrud Buchenrieder · Land · Nigeria (Lagos)

This exploratory qualitative research, conducted in Lagos, Nigeria, used focus group discussions to compare the perspectives of private urban farmers and public sector representatives on innovative urban farming. Urban farmers identified a lack of public sector support for circular agri-food technologies, while public sector representatives attributed issues to farmers' behavioral and educational shortcomings, including poor coordination. These differing views highlight complex dynamics and a need for structural changes and stakeholder dialogues to develop effective urban farming policies in Sub-Saharan Africa.

Jean de Dieu Minengu, Aiko Ikonso Mwengi, Romain Kawanga, Simon Mwengi, Oscar Mangunda Yama · Revue Africaine d’Environnement et d’Agriculture · Africa

Market gardening in Kinshasa's urban and peri-urban areas faces multiple constraints, including land insecurity, low natural soil fertility, the incidence of diseases and pests, weak technical support, climate hazards, poor input supply, and problematic marketing systems. These constraints limit yields in production sites and hinder the development of market gardening activities.

ke Chinelo Gloria, Eze H.C, Obasi C.J, Euphemia Afoma Ikegwuonu, Okonkwo Ngozi Nonyelum · International Journal of Research Publication and Reviews · Nigeria

To evaluate the water quality of the Obibia River in Amawbia, Anambra State, Nigeria, water samples were collected monthly and assessed for bacteriological and physicochemical parameters. The study identified multiple bacterial isolates, including Escherichia coli, Klebsiella pneumoniae, Salmonella enterica serovar Typhi, and Vibrio cholerae. Notably, E. coli, S. Typhi, and V. cholerae were frequently observed in both rainy and dry seasons. These findings suggest the necessity of adequate treatment before use and periodic evaluation of the water's quality for drinking and urban agricultural purposes.

Olivier Grünberger, Radhouane Hamdi, Manon Lagacherie, Hanène Chaâbane · Journal of Environmental Science and Health Part B · Africa

Two years of monthly water sampling and hydrological monitoring at the outlet of the Wadi Guenniche watershed (86 km², with rainfed cereal, legume and orchard cultivation and irrigated market gardening) in northern Tunisia, a tributary of the Bizerte coastal lagoon, tested for 469 pesticide active ingredients and metabolites. Twenty-nine pesticide active ingredients and 2 metabolites were detected in the water, 24 of which are authorized for use in Tunisia; 14 of the authorized substances had never before been mentioned in farmer surveys. The five most frequently detected herbicides and metabolites were AMPA (100%), glyphosate (94%), simazine (94%), 2,4-D (70%) and deisopropylatrazine (DIA, 47%). The detection frequency and concentration range suggest phytosanitary pressure and water contamination comparable to the northern Mediterranean shore, indicating a need for further study of pesticide use and fate on the southern shore, particularly in Tunisia.

Gizaw Ebissa, Aramde Fetene, Hayal Desta · City and Environment Interactions · Ethiopia

Treated wastewater from the plant serving Bole Lemi Industrial Park (BLIP) in Addis Ababa, Ethiopia was sampled at the treatment plant's influent and effluent and analyzed using a treated wastewater quality index (TWWQI) to assess suitability for urban irrigation agriculture. The aggregate TWWQI classified the water as 'very poor' for urban irrigation agriculture, with heavy metals contributing 85% of that grade, nutrient load 4%, salinity 8%, and miscellaneous contaminants 4%. Discrete indices varied: heavy metals scored 'very polluted', nutrients 'excellent', salinity 'poor', and miscellaneous contaminants 'good'. Contaminant removal efficiency ranged from 30% to 100% (58% in aggregate), and some contaminants showed higher concentrations in the effluent than the influent, indicating the treatment plant failed to remove them. Cr3+, Cl− and TDS contributed most to the poor rating, and the plant was found to need upgrading to increase removal efficiency.

Arcadius Martinien Agassin Ahogle, Sammy Letema, Gertrud Schaab, Veronica Ngure, Abraham R. Mwesigye, Nicholas Kibet Korir · Frontiers in Soil Science · Kenya (Nairobi)

This study assessed heavy metal and trace element contamination risks in peri-urban farmlands in Nairobi city catchment, Kenya, by analyzing 60 soil samples from ten vegetable farming zones. Results showed elevated concentrations of elements including As, Cd, Mn, Pb, and Zn, with some exceeding permissible agricultural thresholds. As, Cd, Hg, and Pb exhibited high ecological risks, with Cd contributing 46-66% of the overall risk.

Tinashe P. Kanosvamhira · Urban Forum · South Africa

This narrative literature review analyzed 62 peer-reviewed articles on urban agriculture in South Africa from 1993 to 2022. The findings indicate several knowledge gaps, including an under-representation of secondary cities and a general productivist focus in most studies, which limit understanding of urban agriculture for sustainable cities.