Research & reports

Álvaro Luis José Reyes Córdova · Horizontes Amazónicos · Ecuador

A bibliographic review of research on water quality in the Puyo River and its tributaries in Pastaza, Ecuador, compiled studies from scientific databases and institutional repositories reporting physicochemical, microbiological, and heavy metal parameters. The main sources of contamination were found to be wastewater discharges, fecal coliforms, and accumulation of heavy metals such as lead and mercury linked to urban, agricultural, and mining activities, with community perception aligning with technical findings as most of the population rated the water poor quality and associated it with health problems. Over the past twenty years, a progressive deterioration in water quality parameters has been documented, with increases in turbidity and pathogenic microorganisms despite some isolated recovery efforts, and the review concludes that lack of attention from the municipality and prefecture, together with the absence of continuous monitoring, is worsening the water crisis and demands comprehensive, participatory governance.

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.

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.

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.

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.

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.

Edwin Javier Ortega Zúñiga · Ediciones Comunicación Científica eBooks · Colombia

A study of Palmira, Colombia — a city with a long tradition as the country's agricultural capital — finds that it nonetheless faces significant food insecurity. Prior research reviewed in the study attributes this to an aging rural population and young people's declining interest in farming (which has shrunk the available labor force and limited adoption of new technology), gender inequality that restricts women's access to agricultural resources and decisions, climate change impacts such as droughts and floods on production, and accelerated urbanization that has reduced cropland and fragmented the agricultural landscape. As a potential response, the study describes a pilot project at four sites in the city that installed small-space vegetable production systems, which it reports functioned as a viable source of fresh food in dense urban settings. The authors call for a multidisciplinary approach combining social, economic and environmental factors to address food insecurity in Palmira.

Parisi A., Walthall B., Clerino P., Firmbach P., Onyszkiewicz M., Vicente Vicente J. L. · Environmental Evidence · Global

A protocol for a systematic map of the scholarly literature on the relationship between urban agriculture (UA) and gentrification. The authors note that existing accounts variously present gentrification as a possible outcome of UA activities, as a risk that UA initiatives themselves face, and as other kinds of relationship, and argue that these divergent accounts are partly explained by different theoretical engagements with gentrification and by the breadth of activities gathered under 'urban agriculture'. It sets out the search and review strategy and aims to expose gaps in dominant academic discourses. Being a protocol, it reports no findings yet.

Ylva Wallinder · Local Environment · Europe

A study of Gothenburg, Sweden, examines the city council's shift over the past decade from associational (collective) urban gardening toward entrepreneurial gardening on municipal land, promoted through a scheme called "from garden box to hectare" that draws residents into entrepreneurial training while taking municipal gardening classes. Analyzing the consequences of this commodification of urban sustainability projects, the study finds that socio-economic resources and social relations both limit and strengthen entrepreneurial gardening practices and participants' quality of life, and that perceived competition among gardeners has turned urban gardening into a lonely, precarious, and individualized activity compared with the formalized associational gardening the municipality previously promoted. The finding points to a mismatch between the local government's sustainability visions and gardeners' actual experience.

Jennifer Newell, Siobhan Cox, Rory Doherty · Urban Agriculture & Regional Food Systems · Global

A systematic review synthesized literature on the oral bioaccessible fraction (BAF) of arsenic, cadmium, chromium, nickel, and lead in vegetables grown on contaminated soils, drawing values from multiple online databases across potentially toxic elements (PTEs), in vitro test methods, and vegetable types. The review starts from the premise that many urban and peri-urban brownfield sites carry a legacy of soil metal and metalloid contamination, so crops grown there may pose human health risks. Median PTE BAFs ranked Cd > Ni > Cr > As > Pb; among in vitro methods, the unified BARGE method (UBM) produced the highest median BAFs (63.0% gastric, 59.6% gastrointestinal); and by crop type, BAFs ranked non-vegetables (e.g., rice, fungi) > legumes > root vegetables > bulb vegetables > leafy vegetables.

Javier Bayo, Joaquín López-Castellanos, Marta Doval-Miñarro, Sonia Olmos · Scientific Reports · Spain

An ATR-FTIR analysis of 11 commercial compost products found microplastics in every sample, averaging 137.65 ± 6.01 items/kg dry weight and up to 631.14 mg/kg. Eco-labeled composts had significantly lower microplastic abundance, size, and concentration than non-eco products. Microplastic concentration correlated negatively with pH and nitrogen content and positively with organic matter content.

Jacob Wallace · Waste Dive · United States

NYC's Department of Sanitation began enforcing mandatory curbside organics separation on April 1, 2025, issuing nearly 2,000 summonses in the first week, but Mayor Adams paused broad enforcement through 2025 on April 18, limiting fines to persistent violators. The city had distributed about 190,000 free bins and sold 63,000 more, and organics diversion had risen 65% from FY2022 to FY2024.

Consell de la Generalitat Valenciana · Diari Oficial de la Generalitat Valenciana (DOGV) / BOE · Spain

A decree-law issued by the Consell (Valencian regional government) on 4 February 2025, published 5 February 2025, amending the 2018 Huerta law and its implementing plan (Decreto 219/2018) to simplify administrative procedures for reconstruction following the 29 October 2024 DANA flooding. It abolishes the Huerta Council and chapters on agrarian development planning and farm inventories, and relaxes urban-planning parameters for agricultural buildings.

Ministry of Sustainability and the Environment, Singapore · Ministry of Sustainability and the Environment, Singapore · Singapore

On 26 September 2025, Minister Grace Fu replied to a parliamentary question on progress toward the "30 by 30" goal, stating that less than 10% of Singapore's food consumption is currently produced domestically. She called the goal "aspirational," set before COVID-19 under more favourable conditions, while noting locally produced hen eggs exceed 30% and beansprouts exceed 50% of local consumption, and that the alternative protein industry faces high energy costs and insufficient consumer acceptance.

U.S. Environmental Protection Agency · U.S. Environmental Protection Agency (EPA) · United States

This EPA page (last updated December 22, 2025) explains chromated copper arsenate (CCA), a wood preservative used since the 1940s for utility poles, posts, and other structural lumber. Manufacturers voluntarily ended CCA use for residential wood products in December 2003. EPA notes cancer and non-cancer health risks for workers and environmental risks to aquatic invertebrates and plants, while stating there is no health risk to the general public; removal of existing CCA structures is not mandated, though periodic sealant coating is recommended to reduce leaching.

Bauer W., Titz A. · Nature-Based Solutions · Malawi (Lilongwe)

Urban Nature-based Solutions (NbS) are promoted globally as multifunctional and cost-effective, and municipal interest is growing in cities of the so-called Global South. Yet research remains clearly biased toward the Global North, with particularly few studies on cities in Sub-Saharan Africa — leaving a high risk that maladapted NbS, modelled on examples from elsewhere that do not meet local requirements, get adopted. This article examines the barriers to adopting urban NbS in Malawi's cities and the opportunities for successful implementation, drawing on qualitative data (workshops, narrative expert interviews, group discussions) gathered over five research stays in Lilongwe between 2022 and 2024, and analysing in detail the strategies used by those implementing the Lilongwe Ecological Corridor Initiative (LECI), a large-scale NbS in the capital.

Chmielewski J., Wszelaczyńska E., Pobereżny J., Florek-Łuszczki M., Gworek B. · Sustainability · Poland

The study sampled 112 items — 72 vegetable and 40 fruit — from 16 allotment gardens in Warsaw and measured Fe, Mn, Zn, Cu, Pb and Cd. Vegetables accumulated markedly more heavy metals than fruits, and leafy vegetables grown near high-traffic roads carried the highest Pb, Cd and Zn. Lead exceeded permissible limits by six to twelve times and cadmium by one to thirteen, leading the authors to advise against growing tomatoes in urban settings. Only trace amounts appeared in fruits, and the Hazard Index rated the fruits alone as safe. The paper calls for continuous monitoring of urban garden soils, remediation of contaminated ground and safer growing practices.

Zhe Zhu, Faith Ka Shun Chan, Gang Li, Mengxia Xu, Meili Feng, Yong‐Guan Zhu · Soil & Environmental Health · China

This review examines urban agriculture in China, identifying three forms: small-scale, capital-intensive, and tourism-type, each with benefits and challenges shaped by local context and government policies. Despite benefits like improved community cohesion and environmental sustainability, urban agriculture in China faces significant limitations including land availability, capital shortage, market access, and insufficient governmental support. Strategies and four recommendations are proposed to address these challenges.

Sreejith Aravindakshan, Hage Aku, Michi Tani · · India

This study investigated factors inducing the emergence, sustenance, and sustainability of urban agriculture using primary data from urban farming households in Kerala and Arunachal Pradesh, India. The research indicates that urban agriculture has provided questionable environmental gains and has not significantly improved urban food security, especially among the poorer sections.

José Luis Chaves, Alexandre Boleira Lopo, G. M. OLIVEIRA, J. F. ARAÚJO, Luciano Sérgio Ventin Bomfim, J. A. CASTRO · Editora Científica Digital eBooks · Global

This systematic review investigated the viability of animal production in urban and peri-urban agriculture as a tool for food security, using the PRISMA methodology. The review found that while this practice offers benefits like domestic food security and income generation, it also presents negative aspects such as odors, noise, and the transmission of zoonoses. Public policies are needed to regulate the activity and minimize health risks.