Research & reports

Joan Casanelles-Abella, Monika Egerer · Frontiers in Sustainable Cities · Global

A perspective article discusses biodiversity conservation in cities as often afflicted by "suboptimal" situations where human needs and nature's needs are imbalanced or in conflict. In human-dominated landscapes, land use intensification often replaces large habitat patches critical for metapopulation stability with smaller, isolated patches, a pattern Island Biogeography Theory predicts will reduce biodiversity; this may be most extreme in cities experiencing rapid population growth and infrastructure densification, where small urban green spaces, balconies, home and allotment gardens, small forest patches and green walls, become the primary compensatory interventions for retaining habitat. However, under certain conservation frameworks (land-sparing vs. land-sharing, the SLOSS debate), such small, scattered urban green spaces may be predicted to produce suboptimal or even detrimental biodiversity outcomes if their size and isolation prevent them from sustaining viable population sizes. The article notes this "ecology of suboptimals" framing risks a futile perspective on nature conservation in densifying cities, while also considering how rethinking urban environments in light of this situation might be approached.

Julija Bakunowitsch · Urban Planning · Germany

This qualitative study examines a publicly funded urban gardening project in Dortmund, Germany, implemented as a labor-market activation measure on temporarily available land targeting employable welfare recipients. Drawing on interviews, participant observation, and document analysis, it combines the concept of "food justice" with valuation studies to analyze how labor, land, and exchange are valued in everyday practice. The findings reveal tensions between empowerment and dependency, care and control, and social recognition and material precarity: while participants experienced gardening as meaningful work and a source of social participation and belonging, these valuations remained bounded by welfare regulations, temporary land tenure, and charity-based food distribution. The study concludes that such temporary urban gardening projects function as sites of plural, negotiated valuation where justice is enacted only provisionally, through everyday practice, within the limits of welfare governance.

Rabia Admin, Malka Shahzadi, Malika Shahzadi, Muhammed Faisal Rasheed · Social Sciences Spectrum · Pakistan

This study examines women's involvement and empowerment in agricultural activities in Lahore Cantonment, Punjab, Pakistan, based on data from 118 women engaged in agriculture, analyzed using mixed methods including descriptive statistics, chi-square tests, correlation, and multiple regression. The results show that while participation rates among women are high, women are not yet empowered, owing to existing socio-cultural and resource-based obstacles. Significant associations were found between land ownership and women's decision-making, between education and participation, and between access to credit and extension services and involvement in agricultural activities; the correlation matrix showed positive relationships among key variables, and regression analysis identified land ownership, education, and access to credit as significant predictors of women's empowerment. The paper states that changes to law, access to resources, and social support are needed to improve women's agency in peri-urban agriculture, and proposes policy measures including land rights reform, targeted educational initiatives, and improved access to resources.

Nwanaforo E., Obasi C. N., Akande I. O., Nduka J. K., Offor C. C., Abdulai P. M., Udom G. J., Orisakwe O. E. · Biological Trace Element Research · ナイジェリア（オウェリ・アバ・ポートハーコート）

A study of lead, cadmium and copper in urban agricultural systems in three industrial-area Nigerian cities (Owerri, Aba and Port Harcourt), assessing spatial distribution, bioaccumulation and health risks using both deterministic and stochastic (Monte Carlo) approaches. Atomic absorption spectrophotometry found soil concentrations following Pb > Cu > Cd in Owerri and Port Harcourt but Pb > Cd > Cu in Aba, while fish and vegetables followed Pb > Cd > Cu at all three sites. The deterministic assessment found cadmium's incremental lifetime cancer risk exceeded the US EPA acceptable threshold of 1×10⁻⁶ at every site for every sample examined, identifying cadmium as the metal of greatest concern.

Quinton J, Nesbitt L, Connolly JJT, Wyly E · Urban Studies · カナダ（バンクーバー・カルガリー）

Green gentrification describes how greening a neighbourhood — with parks, community gardens and the like — can draw in higher-income households and displace or exclude marginalised residents; the authors note this has rarely been tested empirically, and that the literature has focused almost exclusively on urban neighbourhoods even though the desire for green space is often cited as a reason households move to suburbs. Surveying 104 households in gentrified downtown Vancouver and suburban Calgary new-build neighbourhoods, the study finds green factors were of similar importance to non-green factors such as safety, scenic views and ambience (and, in Vancouver, proximity to entertainment and transit). Proximity to green space mattered more than overall neighbourhood greenness, and private green space mattered more in the suburbs. Greening, in other words, is not the sole driver, and green-gentrification research needs to widen its geography beyond dense city environments.

Birhanu MW, Negussie ZT · The Scientific World Journal · エチオピア

A PRISMA-based review synthesising peer-reviewed articles published between 2015 and 2025 on the status, challenges and opportunities of home and urban vegetable gardening in Ethiopia. It frames urban and home-based gardening as a practical response to food insecurity, malnutrition and environmental degradation in rapidly urbanising areas where the search for better opportunities has driven rising unemployment and limited access to nutritious, affordable food. The barriers it identifies — limited access to land and clean water, gendered barriers to women, limited technical knowledge, inadequate extension services and weak institutional support — all hinder production and sustainability. It further notes that widespread irrigation with untreated wastewater poses significant health and environmental risks through heavy-metal contamination and soil-transmitted infectious disease. Opportunities such as using vacant urban lots, promoting vertical gardening and supporting local seed production remain untapped; government support for urban gardening has grown recently but its implementation remains inconsistent. The review also identifies a significant geographical gap within the existing literature.

Liz Ignowski, John Luis Lagdameo, Liel Gonzalez, Arma Bertuso, Pepijn Schreinemachers · Urban Agriculture & Regional Food Systems 11(1) · Philippines (Quezon City, Metro Manila)

A quantitative survey of 300 urban food producers in Quezon City, one of the 17 cities of Metro Manila, examining who practises urban agriculture, the methods and technologies used, the challenges met and the benefits gained. Production is mainly small-scale and subsistence-oriented, with commercialisation limited except among those with access to agricultural land. Self-produced food does increase access to fruit and vegetables, but participation reflects economic vulnerability rather than food sufficiency, and both scale and commercialisation depend strongly on land access — a structural barrier in dense cities. The authors conclude that urban agriculture in Quezon City acts as a safety net rather than an income source, while also providing enjoyment and stress relief, and that urban food-security policy should be realistic about the limited role of urban food production.

Paul Emile Tchinda, Thi-Thanh-Hiên Pham · Canadian Geographies / Géographies canadiennes 70(3) · Cameroon (one large and one medium-sized city)

Urban agriculture appears in many sustainability agendas yet has been ignored in the public policies of many African countries. Combining multi-scale mapping (city and neighbourhood) with semi-structured interviews in one large and one medium-sized Cameroonian city, this study tests how well those techniques characterise urban agriculture for local decision-making. Mapping from 5-metre SPOT satellite imagery gives a general grasp of the spatial distribution of practices, but crop types, emerging entrepreneurial practices and the temporality of crops are invisible to it and surface only through field mapping and interviews. Echoing critical remote-sensing scholarship, the authors propose a methodological framework for profiling urban agriculture and argue that the choice of research method shapes our understanding of it, so it should be made with each city's specific characteristics in mind.

Jeong D., Li L., Perez-Quesada G. · Choices Magazine (Agricultural & Applied Economics Association), 2nd Quarter 2026 · United States

An analysis of community garden siting through an environmental cost-benefit framework, organised around two direct costs (land and water) and two externalities (water pollution and gentrification). Cheap vacant parcels can carry remediation and infrastructure costs that exceed those of pricier development-ready sites over a garden's planning horizon, and in arid regions irrigation can be up to 34% of annual maintenance cost. On the externality side, weak nutrient management lets nitrogen and phosphorus accumulate and risk groundwater contamination, and community gardens can raise adjacent property values by 3–4% initially and around 7% within five years, potentially displacing the lower-income residents they are meant to serve. The authors note that the absence of a comprehensive geo-referenced inventory of community gardens — with establishment dates, tenure arrangements and management practices — constrains rigorous cost quantification and causal analysis.

James Comtois · Institutional Investor · Global

Signatories to the UN Principles for Responsible Investment grew from 63 institutions with $6.5 trillion under management in 2006 to 2,450 with $80 trillion in 2019. The article reports a research paper by Demirer and Zhang arguing that institutional ESG investing is largely herding driven by fad, reputational concern and fund flows, and has improved neither corporate ESG engagement nor investment performance. At the time of writing, global ESG fund inflows had fallen 50 per cent over the previous year, with a record $12 billion withdrawn in a single quarter.

Plinth · Plinth · United Kingdom

Published 5 April 2026 and updated 14 June 2026. Full cost recovery means funders covering not only a project's direct costs but its proportional share of overheads — rent, finance, IT, HR and chief-executive time. The article works through an example where two of ten staff (20 per cent of capacity) deliver a project, so £28,000 of £140,000 in annual overheads is added to £85,000 of direct costs for a £113,000 budget, and notes that overhead rates of 15–25 per cent are common sector guidance. It argues that accepting grants below true cost is a structural funding problem rather than a budgeting error, with consequences including staff burnout and governance risk, and notes that charity staff earn roughly 7 per cent less per hour than equivalent roles elsewhere in the economy.

Kremer, Peleg, Borowiak, Craig, Scolio, Madeline · Journal of Agriculture, Food Systems, and Community Development · 米国（ペンシルベニア州フィラデルフィア）

US community gardens embody a conundrum: vital to community well-being and integral to urban social infrastructure, yet profoundly vulnerable through insecure land tenure, fragmented policy support and systemic disinvestment. This reflective essay examines the Philadelphia Garden Data Collaborative (PGDC), a multistakeholder initiative documenting, protecting and advocating for community-managed green space, from the authors' position as participant researchers. It traces the shift from grassroots mapping to coordinated data stewardship, which enabled both emergency interventions (such as preventing sheriff-sale evictions) and long-term preservation strategies, and examines the ethical dilemmas of collecting sensitive community data where bureaucratic neglect has rendered gardens invisible and where visibility can expose them to new risks. It concludes that data can strengthen advocacy and inform policy, but must be coupled with secure tenure mechanisms and sustained public investment.

Rduch Paulina, Hodor Katarzyna, Wilkosz-Mamcarczyk Magdalena · Cities · ポーランド・チェコ

A study of Katowice (Poland) and Brno (Czech Republic) examining how family allotment gardens function as greenery in city centres, together with the legal regulations that govern them. Drawing on statistical and cartographic data, it shows a downward trend in the area of allotment gardens within cities.

Oyewole Michelle T., Pellow David N., Cassels Susie · Environmental Justice · 米国

A study measuring soil lead by X-ray fluorescence at 31 Brooklyn public schools with active garden programmes, sampling both garden beds and adjacent school grounds. Proximity to 306 known environmental hazard sites was mapped geostatistically and combined with demographic data and soil-management surveys. Of the samples, 42% exceeded the US EPA's minimum screening level for child-accessible soils near known lead sources (100 ppm); garden soils showed lower average lead concentrations than adjacent school-ground soils. The authors argue that soil lead in schools, and the disparities in it, have received far less attention than lead in paint and water.

Nkrumah B. · Urban Science · アフリカ（都市部・系統的レビュー）

A systematic review of the irony between abundant arable land and persistent hunger in African cities. It asks why a disproportionate share of urban residents do not produce their own food, even as food insecurity rises with heavy reliance on market-bought food, high poverty and rapid urbanisation, screening peer-reviewed literature via PRISMA and five inclusion benchmarks to clarify the debate on low uptake of urban agriculture.

Rao X., Zahid A., Ye X., Jain D., Duffield N. · Urban Informatics · 国際（論考）

A Perspective arguing that controlled environment agriculture (CEA), driven by venture capital and profit-maximising imperatives, has delivered limited scalability, narrow crop diversity and minimal engagement with spatial equity — the fair distribution of food infrastructure across urban geographies. It calls for repositioning CEA not as a standalone technological fix but as a component of urban infrastructure delivering co-benefits for food justice, public health and environmental resilience.

Hinch J. · Southeastern Geographer · 米国フロリダ州タンパベイ

This study builds an equity-focused, GIS-based multi-criteria decision analysis model integrating socioeconomic, logistical and environmental variables to assess community garden suitability across census tracts in Tampa Bay. High-suitability tracts cluster somewhat in Hillsborough and Pinellas Counties, existing gardens align moderately with modelled suitability, and the paper shows both the utility and the limits of spatial models in equitable urban agriculture planning.

Noxolo B.M., Kanosvamhira T.P. · Urban Agriculture & Regional Food Systems · 南アフリカ・ケープタウン（低所得地区）

Surveys and interviews assess whether hydroponics, of interest because dense settlements leave little space, is actually viable in Cape Town's low-income urban areas — deliberately supplementing a literature skewed towards Global North cities. Farmers perceive benefits in improved yields, water conservation and efficient land use, all valuable in a water-scarce, space-constrained city, but high setup costs and limited government support remain significant obstacles. Drawing on urban political ecology, the paper argues these financial and institutional barriers are rooted in historically produced inequality and ongoing capitalist dynamics of urban development. It concludes that while hydroponics has potential as a sustainable alternative, its high costs hinder broader applicability, and it is not yet a viable large-scale route to food security where resources are unequally distributed; supporting actors must first address financial feasibility and local expertise.

Darrow S., Kathi S., Liebe R., Cline L.L., Moss J.Q. · Urban Agriculture & Regional Food Systems · 米国オクラホマ州（農村・都市・近郊）

Oklahoma's specialty crop sector is in decline — vegetable operations fell from 799 in 2007 to 482 in 2022 — yet regional fruit and vegetable producers remain the primary supply foundation for farmers' markets, food hubs and direct retail serving urban and peri-urban communities, so producer viability is itself an urban food access and public health concern as food deserts expand. Five semi-structured focus groups with 29 experienced producers from rural, urban and peri-urban Oklahoma were analysed by open coding thematic analysis in NVivo, with saturation confirmed iteratively and rigour established through member-checking, peer review of codes and field note triangulation. The 180 initial codes were organised into 10 parent codes and three themes: the countercultural philosophy of production, the lack of accessible resources, and industry barriers preventing development — compounding disadvantages at cultural, institutional and structural levels. The authors call for a statewide local food system plan, a growers' association and dedicated local-food-system extension roles.

Kanosvamhira T.P., Magidi M. · International Journal of Agricultural Sustainability · 南アフリカ・ケープタウン／ジンバブエ・ノートン

A qualitative case study comparing the motivations, operational dynamics, land access challenges and legislative contexts of urban agriculture in two contrasting cities — Cape Town (South Africa) and Norton (Zimbabwe) — through stakeholder interviews and policy analysis, guided by social capital theory. In Cape Town urban agriculture is semi-institutionalised, backed by governmental and civil society actors and framed within wider food justice and community development agendas, yet practitioners face significant constraints from land access, urban policy fragmentation and competition over space. In Norton it is largely informal, a survivalist response to persistent socio-economic hardship with minimal formal support but relatively flexible regulation, where land-tenure insecurity and the threat of eviction are the pressing concerns. The paper argues that context-specific legislative frameworks, secure land rights and inclusive urban planning are the enabling conditions, situating urban agriculture within debates on land governance and urban informality.

Kissoly L. · Frontiers in Sustainable Food Systems · タンザニア・ダルエスサラーム

An exploratory qualitative case study and policy analysis of urban agriculture's current landscape and possible futures in rapidly urbanizing Dar es Salaam, drawing on targeted literature and document review, a policy and regulatory scan, and 52 key informant interviews with municipal actors, urban farmers and food-system practitioners conducted between April and September 2025. Urban agriculture is valued for household food supplementation, small-scale income and fresh-food provisioning through short-cycle vegetable production close to consumers, but remains shaped by tolerated informality, insecure land access, fragmented regulation, contamination risks, weak institutional coordination and pressure on peri-urban land. Five evidence-informed trajectories are proposed — managed river-corridor cultivation; sacks, buckets and roofs for dense-ward micro-production; institutional land clusters; peri-urban foodshed belts with circular-resource hubs; and small-scale aquaculture with insect-based feed — presented explicitly not as tested feasibility models but as differentiated options requiring further technical, environmental, spatial and economic assessment. The paper argues the future depends not on a single large-scale model but on risk-sensitive, institutionally grounded forms of support.

Leanne Idzerda, Calin Lazarescu, Tricia Corrin, Eric Vallières, Alix Couture, Sara Khan, Lynn McIntyre, Valerie Tarasuk, Alejandra Jaramillo Garcia · Health Promotion and Chronic Disease Prevention in Canada · Canada

A systematic review (PROSPERO CRD42021254450) searching four databases to 19 February 2025, with duplicate independent screening, risk-of-bias assessment and certainty grading, on food-based interventions that could reduce household food insecurity (HFI) in Canada. Exposure to food voucher programmes may reduce HFI, but exposure to food box, community gardening, school food, hunting and fishing, and food charity programmes may have little to no effect on HFI. The authors conclude that because HFI is primarily an economic problem, food-based responses are unlikely to have a major impact on overall HFI and a more comprehensive public policy approach is required. This is direct counter-evidence to framing community gardens as a food-insecurity intervention.

Hang Yu, Mohd Yazid Mohd Yunos, Mohd Nazri Saidon, Mohd Amirul Hussain · Landscape Research · China (Shenyang)

This study critically examined how community-led edible landscapes intersect with tensions of urban redevelopment, memory politics, and governance ambiguity in post-industrial Shenyang, China. Using a qualitative case study approach, including participant observation, semi-structured interviews, and spatial documentation, findings showed that while edible landscapes can revitalize neglected spaces and evoke industrial memory, they also face instability, informal governance, and socio-environmental risks.

Paul Β. Thompson · · Global

This article discusses urban agriculture, noting that the decline of grocery stores in inner cities and projected vulnerabilities in megacities outside the global West suggest distinct moral imperatives. It contrasts urban agriculture with rural resilience and sustainable intensification, highlighting its focus on consumption and present needs. The article describes two urban agriculture archetypes: one embracing high-tech solutions and another emphasizing local solidarities and urban-based control over the food system.

Florien Misago, Isaac Nzayisenga, Henri Jacques Ngirinshuti, Leon De Pere Irakoze, Richard Mind’je · East African Journal of Agriculture and Biotechnology · Rwanda (Kigali)

This study evaluated the potential of rooftop and wall-based urban agriculture to enhance food security in Gasabo District, Kigali, Rwanda. It used GIS and remote sensing to map suitable spaces and assessed 400 household heads using the Household Food Insecurity Access Scale (HFIAS). Findings showed that 41.5% of households experienced moderate to severe food insecurity, and approximately 32% of rooftops and walls were structurally appropriate for urban agriculture. While 57.8% of households expressed willingness to adopt rooftop or wall gardening, 67.4% cited structural and financial constraints.