Research & reports

Sumit Vij, Vishal Narain · Wiley Interdisciplinary Reviews Water · Global

This review addresses a knowledge gap on how peri-urban residents in Asia and Africa adapt to the impacts of urbanization and climate change on water security. As rural-urban boundaries rapidly blur in the global South, peri-urban spaces are characterized by weakening access to water resources, depleting common property institutions and poor civic engagement, and the review presents the persistent marginalization of peri-urban residents from a water security perspective, while also showing that they do develop adaptation measures. Existing literature is found to focus primarily on (1) increased vulnerability of peri-urban agriculture and allied sectors, (2) barriers and enablers to water-security-related adaptation planning, and (3) justice in peri-urban areas, and the review calls for further study of emerging cooperation and collective action that could reduce conflicts between peri-urban and urban inhabitants and improve water security.

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.

Abdul-Salam Ibrahim, Marney E. Isaac, Thembela Kepe · Land Use Policy · Ghana

Focusing on Ghana, where floods driven by urbanization and climate change are destabilizing urban systems in which land tenure is integral, this study drew on political ecology and land-tenure-security frameworks to examine how floods affect the land tenure security of flood victims. Based on semi-structured interviews with flood victims and planning officials, it found that flood-induced rezoning and new planning schemes, tenant insecurity, relocation, loss of land documents, and threats to urban agriculture all affect flood victims' land tenure security; possessing land documents was found to be important for tenure security but not an absolute condition for victims' perceived security. Post-flood land-use planning for flood risk management was found to have dual potential — it can enhance tenure security and bolster community resilience, but when carried out in an exclusionary way that overlooks the urban poor, it can instead perpetuate inequality and tenure insecurity. The study recommends tenure-responsive land-use planning that embeds contextual, procedural, and distributive equity principles into planning responses to urban floods.

Kelsey Ryan-Simkins · Local Environment · United States (Ohio)

This study used multilevel negative binomial regression to examine the relationship between urban agriculture site locations and sociodemographic and neighbourhood environmental characteristics at the census tract level in Ohio, USA. Findings challenge the idea that urban agriculture is placed in areas with low food access, raising questions about the food-access rhetoric used to promote urban agriculture, a movement critiqued for often being led by upper-class, urban elites, and contribute to debates about the roles of race and gentrification in urban agriculture.

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.

Fetty Dwi Rahmayanti, Andi Gunawan, Anas Miftah Fauzi, Edi Santosa · Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) · Indonesia (Jakarta)

A mixed-methods study assessing biodiversity risk from urban agriculture activities in East Jakarta, Indonesia, combining a literature review with a field survey of questionnaires on respondents' perceptions of biodiversity risk to flora and fauna. The results showed the p-value exceeded the alpha level (0.05), indicating that urban agriculture in East Jakarta does not significantly affect biodiversity risks to flora and fauna.

Johanna Bock, Márcio Zamboni Neske, Martin Krauß, Andrea Dombrowski, Jörg Oehlmann · Environmental Sciences Europe · Europe

Focusing on small water bodies in private urban gardens, this study examined whether chemical pollution limits insect diversity, given that gardens make up a significant share of urban green area and can serve as important habitats and stepping stones for insects, while pesticides, fertilizers and chemical run-off from building materials can strongly affect habitat quality and insect biodiversity. Garden pond toxicity was assessed using in vitro and in vivo methods and chemical screening. Of 17 ponds examined, only one water sample and one sediment sample were found non-toxic in a bioluminescence assay with Aliivibrio fischeri. Enhanced dioxin-like activity was measured in seven water and ten sediment samples using a reporter gene assay with Saccharomyces cerevisiae, and most water extracts showed mutagenic potential in the Ames fluctuation assay (Salmonella typhimurium strains YG1041 and YG1042), while most sediment extracts were not mutagenic. Increased larval mortality of Chironomus riparius occurred in five water-sediment systems built from pond samples, correlating positively with in vitro water toxicity and with concentrations of benzothiazole derivatives measured by LC-HRMS, likely originating from EPDM rubber pond liners. Substance composition differed significantly between house and allotment gardens, with higher concentrations measured in allotment ponds. The study concludes that chemical pollution in private urban gardens may have been underestimated to date, and that pond toxicity can severely affect insect populations, warranting further study.

Finn Williams, Ruby Johnston, Aiden Campbell · International Journal of Horticulture and Food Science · Germany

At the Christchurch College of Food Technology in New Zealand, researchers compared five growing systems -- rooftop container, raised bed, peri-urban orchard, rural orchard (reference), and heated greenhouse -- for avocado (Persea americana) cv. 'Hass' under simulated Bavarian Plateau conditions, using a randomized complete block design with four replications over three years (2020-2022). The rural orchard yielded highest at 22.3 kg per tree, peri-urban raised beds achieved 18.7 kg per tree using 56% less land, and rooftop containers (200 L pots) produced only 6.8 kg per tree, confirming that container culture is viable but yield-limited; rooftop systems had the lowest weed pressure, peri-urban orchards supported the richest arthropod biodiversity, and ISSR molecular markers confirmed genetic uniformity among grafted plants across systems, ruling out somaclonal variation as a source of the yield differences.

Jennifer Jettner · Journal of Social Work and Social Welfare Policy · United States

A qualitative study (Journal of Social Work and Social Welfare Policy, 2025) interviewed ten garden leaders representing nine urban and rural community gardens in Alabama, USA, analyzing themes through a racial capitalism and black geographies framework. It found that health-focused garden efforts were white-led while justice-focused efforts were BIPOC-led, and that all of the gardens struggled to engage a racially diverse membership reflective of their surrounding neighborhood. For white-led efforts, the main impediment was found to be importing racial diversity rather than centering and celebrating BIPOC leadership and knowledge. BIPOC-led efforts held differing interpretations of the impact of historical trauma, possibly linked to a "rural imaginary." All gardens studied struggled to engage youth and expressed fear of losing food and growing knowledge across generations.

Ramadha Subhani Aden, Luki Anjardiani · Frontier Agribisnis · Indonesia

Focused on "Merko Hidroponik," a Merck Family Foundation-funded hydroponic (NFT) lettuce enterprise in Banjarbaru City, Indonesia, adopted as urban farming to address declining agricultural land, this study (2025) used descriptive methods to calculate total costs, revenue, profit, and business feasibility (R/C ratio) for the period March 2023 to July 2024, during which 11 planting cycles were completed from seeding through nursery, growth management, harvest, and post-harvest processing. Total costs were Rp7,906,424, total revenue Rp9,920,000, and profit Rp2,013,576, yielding a feasibility ratio of 1.254, concluded to make the business "feasible" to run. However, the study also identifies that the enterprise currently faces problems of root rot disease, managerial inefficiency, and challenges maintaining production continuity.

Talitha Ummiyah Hana, Sulistyodewi Nur Wiyono, Mahra Arari Heryanto, Ahmad Choibar Tridakusumah · MIMBAR AGRIBISNIS Jurnal Pemikiran Masyarakat Ilmiah Berwawasan Agribisnis · Indonesia (Bandung)

A case study of Greenhouse X, an urban farming enterprise in Bandung, Indonesia, found that its hydroponic water spinach (kangkung) supply has not been able to optimally meet market demand, and that its supplier-farmer partners are often inconsistent in meeting supply targets. Using a qualitative case-study method analyzed descriptively, the study identified 19 production risk events. The highest-severity risks (Si=9) were plant death during growth and root rot; harvest delays and unmet product quantity were rated as extreme-impact risks (Si=8).

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.

Pierre‐Alexandre Deyris, Franck Pélissier, Claire M. Grison, Claude Grison · Journal of Hazardous Materials Advances · Global

Herbicide use worldwide has doubled over the past 30 years, and diuron contamination of tropical aquatic ecosystems — affecting food crops such as pineapple — has been reported across Southeast Asia, the Pacific, and Africa. This perspective article examines taro (Colocasia esculenta), a widely cultivated crop whose tubers are consumed locally, as a nature-based means of mitigating diuron impact on tropical aquatic ecosystems through rhizofiltration, i.e., phytoaccumulation of the herbicide by the roots. Analysis of treated tubers found that diuron levels in the tuber core were below recommended European standards, indicating the tubers could remain edible for the local population and confirming compatibility with existing food uses.

Ristina Siti Sundari, Depy Muhamad Pauzy, Hary Firmansyah, Arif Arif, Jhon Hardy Purba · Agro Bali Agricultural Journal · Indonesia

Against the backdrop of urban farming as a strategic response to land scarcity and food security challenges in metropolitan areas, this study examined the financial performance and internal marketing value of shallot (Allium cepa var. aggregatum) agribusiness grown hydroponically using Nutrient Film Technique (NFT) and Deep Flow Technique (DFT) systems across two planting cycles. As a case study at P4S Galih Jaya, Indonesia, the quantitative descriptive research combined direct observation, financial documentation review and structured stakeholder interviews, calculating standard agribusiness financial metrics — production output, net income, Benefit-Cost (B/C) ratio and Break-Even Point (BEP) — while internal marketing indicators (employee understanding, decision alignment and motivation) were assessed via pre- and post-cycle surveys. The DFT system in cycle 2 yielded the highest net income (IDR 2,036,725) and B/C ratio (3.6), while the NFT system in cycle 1 incurred a financial loss of IDR 10,155 with a B/C ratio of only 0.9, indicating it was unprofitable. Internal marketing indicators showed clear improvement between periods, and the study concludes that the choice of hydroponic system affects not only profitability but also internal stakeholder engagement.

Sarah Corcoran, Rachael Condley, Rachel A Liebe, Tuba Khan, Jillian Joyce, Deana Hildebrand, Ashlea Braun · Journal of Hunger & Environmental Nutrition · United States (California)

At a hybrid food and resource center with an attached community garden in California, USA, a longitudinal, sequential explanatory mixed-methods study of 30 patrons (mean age 45.9, 73.3% women) combined quantitative measures (survey and skin carotenoids) with qualitative semi-structured interviews to examine barriers to and facilitators of fruit and vegetable intake. Skin carotenoid levels, a biomarker of fruit and vegetable intake, were largely unchanged before and after (P = .51); among the 26 participants interviewed, facilitators cited included perceptions of quality and alignment with health goals, while barriers included mental health and competing priorities, leading to the conclusion that programs aiming to improve fruit and vegetable intake should prioritize non-diet determinants.

Ioana Florea · · Global

This chapter finds that while collective urban gardening projects represent forms of resistance against market-based food systems, the precarization of urban natures, and real-estate dominance, their everyday practices often fail to deliver on these ideals and intentions, generating incomplete, contradictory, or temporary results. It proposes a heuristic frame linking space, time, and class to review prior urban-gardening research from a political-ecology perspective, tracing how space's materiality, time embedded in plant growth, and class differences conditioning gardeners' access to space and time produce these contradictions.

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.

Jan Grossarth · Discover Cities · Global

This paper critically examines the dominance of quantification—certification scores, KPIs, life-cycle assessment—in sustainability practice for cities and buildings (including urban agriculture), arguing that data-driven metrics strip out the emotional and narrative meaning of sustainability. The authors label the shift from a culturally rich orientation to a purely technical, quantitative practice a "tragedy of sustainability," and argue that narrative-focused interviews and real-life storytelling in architecture and urban planning should not just accompany KPIs and ratings but be prioritized over them. The paper is a conceptual argument, not an empirical study with data or case findings.

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.

Augustin Tshilumba Ilunga, Michel Mbumba Bandi, Albert Tshinyama Ntumba, Damien-Joseph Muteba Kalala · Revue Africaine d’Environnement et d’Agriculture · Democratic Republic of Congo

A study of urban agriculture in Kinshasa, Democratic Republic of Congo—a sector described as vital for food security and employment amid rapid urbanization, food insecurity, and unemployment, where farms face significant challenges including land pressure, restricted access to credit, and lack of institutional support. The study aimed to (i) examine the motivations of agri-entrepreneurs, (ii) assess their impact on farm viability, and (iii) identify the economic and non-economic factors influencing business sustainability, using a qualitative and quantitative survey combining 20 semi-structured interviews across three peripheral zones (via snowball sampling) with documentary analysis. Three categories of entrepreneurs were identified: civil servants farming as a supplementary activity, private-sector employees investing in farming, and traders farming to secure their survival. Non-pecuniary motivations such as social engagement and passion strengthened resilience, but land insecurity, a financing deficit, and lack of training were identified as the major obstacles farms face; observed adaptive strategies included diversification and informal partnerships. The study concludes by calling for integrated strategies to secure land tenure, facilitate access to credit, and professionalize the sector while integrating peri-urban agriculture into urban planning processes.

Md. Rafiqul Islam, Syed Anisur Rahman, Tanvir Ahmed · International Journal of Agriculture and Food Science · Asia

Six heavy metals (lead, cadmium, chromium, nickel, copper, zinc) were measured by atomic absorption spectrophotometry in spinach, amaranth and fenugreek collected from four peri-urban sites around Dhaka, Bangladesh, during January-March 2024, where more than 2,000 hectares of vegetable land are irrigated with untreated industrial and domestic wastewater via canal networks. Lead in amaranth from the industrial-effluent site reached 0.94 mg/kg fresh weight, more than three times the WHO/FAO permissible limit of 0.30 mg/kg, while cadmium, chromium and nickel stayed within permissible limits at all sites and zinc, though highest in absolute terms (8.6-14.7 mg/kg), also remained within safe limits; contamination was highest at the industrial-effluent site and lowest at the borewell-irrigated control site, indicating a localized food-safety risk for consumers of peri-urban leafy greens grown with wastewater irrigation.

Jarosław Chmielewski, Barbara Gworek, Alicja Walosik, Magdalena Florek-Łuszczki · Annals of Agricultural and Environmental Medicine · Poland

Soil (N=196) and root vegetable (N=94) samples from 16 allotment gardens in Warsaw, Poland, were analyzed for manganese, zinc, copper, lead and cadmium and assessed for health risk. Parsley, carrots, beetroots and celery grown in these gardens accumulated elevated levels of all five metals, and the health risk assessment found an increased risk of carcinogenic effects from cadmium and lead in consumers of these root vegetables; the authors conclude consumption of vegetables from the examined gardens should be very limited or eliminated from the diet entirely.

Ikrema Hassan, Innocent Mugudamani, Saheed Adeyinka Oke · Environments · Canada

Top and subsoil samples from Carleton community garden in New Brunswick, Canada, affected by an industrial fire hazard, were analyzed for toxic heavy metals using ICP-OES and ICP-MS, with ecological risk assessed via the ecological risk factor and potential ecological risk index (PERI) and human health risk assessed using a standard approach. Mean concentrations of lead, zinc, copper and tin exceeded permissible limits under Canadian soil quality guidelines and upper continental crust values; nickel posed a high ecological risk across both soil layers while all other metals showed low ecological risk, and overall PERI indicated low ecological threat. In the human health assessment, children faced non-carcinogenic and carcinogenic risk from arsenic exposure while adults did not face risk from any of the metals studied, identifying arsenic as the primary contaminant of concern and children as the most vulnerable population.