Research & reports

Minjae Kong, Kwang-Lai Park, Jin-Kwan Son, Ji-Hoon Shin · Journal of the Korea Society of Environmental Restoration Technology · South Korea (Seoul)

This study investigated the characteristics of rooftop gardens (farms) in 40 areas in Seoul, Korea. Cabbage, lettuce, pepper, and mini-tomatoes were the most preferred vegetables and fruits. Problems observed in rooftop gardens during cultivation included drainage systems, soil management, the cost or quality of planting mats, and diseases and insects.

Sarah Leonard · Dissent · United States

This article explores the perilous state of food and food politics in America and a wide range of responses on the Left. It describes how the existing farm bill led to a policy disaster, the relationship between Reagan-era deregulation and the obesity epidemic, and the labor exploitation endemic to the elite dining experience. The study reveals challenges in governance within the American food system and its socioeconomic impacts.

Jodi L. Sangster, Andrew Nelson, Shannon L. Bartelt‐Hunt · International Journal for Service Learning in Engineering Humanitarian Engineering and Social Entrepreneurship · United States (Omaha)

Soil and vegetable samples were collected from a community garden in Omaha, Nebraska, which had known soil lead contamination. Total lead content was evaluated using atomic absorption spectroscopy, revealing lead concentrations in soil ranging from 4 to 574 ppm, with an average of 128.4 ppm in growing beds and 31.5 ppm in OmaGro compost. Lead was also present in vegetable samples at or below 16.25 ppm.

Adam J Long · Scholarship @ Claremont (The Claremont Colleges) · United States (Washington, DC)

This study investigated heavy metal soil contaminants in 13 urban community gardens in Washington, DC, analyzing 45 soil samples using X-ray fluorescence (XRF). While most samples fell below US EPA action levels for common contaminants, high concentrations of lead (above the US EPA action level of 400 ppm) were found in the native soil of three garden sites, meriting concern due to potential health problems in children.

Sjsu ScholarWorks, Gabriel R. Valle · · United States

This paper explores the self-valorization of work in community gardens as a path to environmental justice, arguing that community gardens disrupt capital's system by removing food as a commodity and revaluing time outside market-driven speed. The Chicano community, being susceptible to workplace inequalities, has a particular stake in this self-valorization, as these inequalities are reflected in unhealthy communities, economies, and environments. The study suggests that self-valorization through work creates natural wealth, reconstructing time, oppression, and communities.

Josh Beniston · The Knowledge Bank (The Ohio State University) · United States (Ohio)

An experiment on assessing and managing soil quality for urban agriculture was conducted during the 2011 and 2012 growing seasons on demolished vacant urban lots in Youngstown, Ohio. Soil compaction was identified as a primary constraint, with high bulk density values of 1.79 g cm⁻³ for in-ground plots and 1.55 g cm⁻³ for raised beds. Crop yield data from 2011 showed that both compost-amended and compost + biochar-amended plots had significantly greater crop yields than control plots, with compost + biochar plots achieving the highest harvest index values.

Y. Niang, S. Niang, Saliou Niassy, Y Dieng, Mohamed Gaye, K. Diarra · International Journal of Biological and Chemical Sciences · Senegal

This study assessed the effect of wastewater on the agronomical performance and hygienic quality of tomato and lettuce in Senegal, comparing it to tap water, irrigation modes, and fertilizers. While tomato showed no pathogenic germs with wastewater, lettuce watered with wastewater via aspersion contained significantly more pathogenic germs than those watered in draining mode. Significant differences in yield and fruit size were observed between lettuce treated with tap water and wastewater.

Nancy Karanja, Mary Njenga, G.K. Mutua, Carl Johan Lagerkvist, E. Kutto, JJ Okello · Journal of Agriculture Food Systems and Community Development · Kenya (Nairobi)

A study in three peri-urban sites in Nairobi, Kenya, assessed heavy metal, nitrate, and pesticide residue levels in wastewater-irrigated kale. Elevated levels of boron, cobalt, chromium, copper, lead, zinc, and nickel were found in vegetables at two sites, with high soil loadings of nickel, arsenic, lead, chromium, copper, and zinc attributed to chicken manure. Pesticide residues of diazinon, cypermethrin, biternol, and profenofos exceeded permissible limits in kale at one site, suggesting consumers may ingest significant amounts of contaminants.

Sebastian U. Ugbaje, John O. Agbenin · International Journal of Environmental Studies · Nigeria

A pot experiment in Zaria, northern Nigeria, evaluated the chemical forms and phytoavailability of Cr, Ni, and Pb in savannah soil amended with two urban wastes and planted with sorghum. While urban waste application increased total metal concentrations in the soil, only Pb uptake by sorghum increased, with no corresponding increases for Cr and Ni. A single application of urban wastes significantly increased Pb uptake by sorghum, raising concerns about the long-term consequences of such applications in urban and peri-urban agriculture, especially regarding children's exposure to Pb.

Mahbubur Meenar, Brandon Hoover · Journal of Agriculture Food Systems and Community Development · United States (Philadelphia)

This paper examines urban agriculture (UA) projects' role in addressing food insecurity in lower-income neighborhoods of post-industrial U.S. cities, using Philadelphia as a case study. While UA projects are vital, findings indicate concerns regarding their geographic, economic, and informational accessibility, social exclusion, and spatial mismatch between participants and neighborhood demographics. Challenges also exist in distributing fresh produce to impoverished populations and UA's economic contributions in underprivileged areas.

Iwona Makuch · Soil Science Annual · Global

This study investigated the influence of intensive horticulture on lead content and its fractions in soil profiles from house gardens, allotment gardens, and arable fields. It was not determined that the manner of usage had any influence on total lead content or its distribution in soil profiles. However, the usage manner did influence the content and distribution of lead fraction III, which is connected with organic matter, with humus horizons of garden soils showing the highest content.

Mirelys Rodríguez Alfaro, Olegário Muñiz Ugarte, Bernardo Calero Martín, A. Álvarez, Francisco Martínez Rodríguez, Teudys Limeres Jiménez, Mercedes Orphee Montoya, Adriana M. de Aguilar Accioly · DOAJ (DOAJ: Directory of Open Access Journals) · Cuba

This study evaluated the heavy metal content of Cadmium, Lead, and Nickel in organic fertilizers (composts from urban solid waste) and substrates, and their effect on vegetables grown in organoponics in Havana and Guantánamo, Cuba. Composts obtained from unsorted urban solid waste and the substrates prepared from them were found to contain heavy metals, especially Cadmium and Lead, above maximum permissible limits. It was concluded that these products should not be used for food production, as these metals translocate to the edible parts of the cultivated vegetables.

Catherine Rwamba Githuku · Abstracts of postgraduate thesis · Kenya (Nairobi)

This study investigated soil and crop pollution levels resulting from untreated wastewater reuse for irrigation in Kibera and Mailisaba wastewater irrigation farms in Nairobi, Kenya. Analysis of irrigation water, soil, and crop samples (maize, kales, black nightshade, arrowroots) revealed that the Electrical Conductivity (EC) of irrigation water at Mailisaba exceeded recommended levels. Farmers reported adverse effects on crops due to wastewater quality, and despite awareness of health risks, many farmers confessed to not using protective clothing.

Anna‐Katarina Schilling, Helmut Hotzel, Ulrich Methner, Lisa D. Sprague, Gernot Schmoock, Hosny El‐Adawy, Ralf Ehricht, Anna-Caroline Wöhr, Michael Erhard, Lutz Geue · Applied and Environmental Microbiology · Germany

This study investigated the presence of zoonotic agents in small ruminants kept on city farms in southern Germany, sampling feces and nasal liquid from 48 animals (28 goats, 20 sheep) across 7 city farms and one activity playground. Findings revealed that 100% of sampled sheep and 89.3% of goats carried Shiga toxin-producing Escherichia coli (STEC). Staphylococcus spp. were detected in 75% of both sheep and goats, and Campylobacter spp. in 25% of sheep and 14.3% of goats. Neither Salmonella spp. nor Coxiella burnetii was found.

John Jacob, Samuel E. Kakulu · American Journal of Chemistry · Nigeria

Soil and vegetable samples (spinach, jute mallow, and tomato) were collected from farms and gardens across 20 zones within Kaduna, Nigeria, plus two rural control villages about 30 km from the city, and analyzed for heavy metals by Flame Atomic Absorption Spectrophotometer. Pollution Load Index results showed soils in the city farms were moderately enriched with cadmium and chromium and strongly enriched with lead and nickel from anthropogenic sources. Mean soil concentrations of lead and cadmium exceeded WHO/FAO permissive limits for agricultural soil (nickel and chromium did not), while vegetable metal concentrations exceeded the permissive limits for every metal except nickel — a finding flagged as concerning given the toxicity of lead and cadmium in particular, which have no known biological use.

Chinedu Agbakoba, Funmilayo Olayiwala · Zenodo (CERN European Organization for Nuclear Research) · Nigeria

A paper framed as addressing a research gap on eco-friendly pesticide use strategies among urban farmers in Lagos State, Nigeria, health impacts, and environmental protection (2012) states that it conducted a structured literature review with thematic synthesis of key findings. However, the abstract's actual content is limited to generic mathematical-formalism language — establishing "bounded error under perturbation," a "convergent estimation process under stated assumptions," a "stable link between the proposed metric and observed outcomes," and an empirical specification described as a linear regression form (Y expressed as a linear function of X plus an error term) — and does not report specific data or results on actual pesticide practices, measured health impacts, or environmental protection outcomes among Lagos urban farmers. It closes by calling on stakeholders to prioritize inclusive, locally grounded strategies and improve data transparency.

Qing Tian · · China (Beijing)

Based on Agricultural Location Theory, 23 matched soil-wheat sample sets were collected from Beijing's central city, suburban plain and exurban plain zones to analyze the accumulation, chemical forms and bioavailability of lead under differing intensities of human activity. Urban soil showed lead contamination with an average concentration of 35.59 mg/kg above the limit, likely from traffic and industrial emissions, and suburban agricultural soil also showed localized lead contamination from long-term sewage irrigation, with lead more mobile in urban agricultural soil than in suburban soil and least mobile in exurban agricultural soil. The average bioconcentration factor of lead in wheat seeds was a low 0.0044, but some lead concentrations in wheat seeds grown in urban and suburban agricultural soil exceeded the standard limit, indicating a potential health risk to residents in those areas.

Leigh Whittinghill, D. Bradley Rowe · Renewable Agriculture and Food Systems · Global

Urban agriculture faces limitations including competition for space, lack of formalized land use rights, and health hazards from food contamination. Green roof technology is proposed as a method to alleviate these issues, potentially reducing the use of contaminated land and water at ground level. However, for large-scale implementation, installation costs must be reduced, roof weight limitations assessed, and appropriate management practices developed.

Simon Mariwah, Jan-Olof Drangert · Waste Management & Research The Journal for a Sustainable Circular Economy · Ghana

A study in a peri-urban agricultural community in Ghana explored attitudes towards sanitized human excreta as fertilizer, collecting data from 154 households. It found a general negative attitude towards fresh excreta and its handling. While residents accepted excreta could be used as fertilizer, they were unwilling to use it on their own crops or consume such fertilized crops.

Christophe Antonio‐Nkondjio, Billy Tene‐Fossog, Cyrille Ndo, Benjamin Menze Djantio, Serge Zebaze Togouet, Parfait Awono‐Ambene, Carlo Costantini, Charles S. Wondji, Hilary Ranson · Malaria Journal · Cameroon

This study assessed the influence of urban pollution and agriculture on malaria vector distribution and insecticide susceptibility in Douala and Yaoundé, Cameroon, from October 2009 to December 2010. Researchers sampled 1,546 anopheline larval breeding sites and analyzed water parameters. Findings showed mosquitoes from cultivated urban areas exhibited the highest insecticide resistance levels, with urban agriculture, rather than pollution, suggested as the major factor driving resistance.

Stephen Odede. Shisanya, Sheryl L. Hendriks · Development Southern Africa · South Africa

This study evaluated the contribution of community gardens to alleviating food insecurity for 53 community gardeners in Maphephetheni, KwaZulu-Natal, South Africa. Using the Household Food Insecurity Access Scale, it was found that 89% of these households were anxious about food supplies, consumed insufficient food, and were severely food insecure. Additionally, 72% consumed poor quality food. Community gardens were unable to solve the problem of food insecurity, but their contribution to consumption cannot be entirely ignored.

L Ndiaye M, Y Dieng, S. Niang, Rak H, Mauro Tonolla, Raffaele Peduzzi · African Journal of Microbiology Research · Senegal (Dakar)

A survey in Dakar, Senegal, assessed the effect of irrigation water quality on Salmonella spp. incidence in lettuce. Microbiological analysis revealed that 35% of irrigation water was contaminated by Salmonella spp., with no significant difference between groundwater and wastewater. Lettuce from Dalifort and Grand-Yoff markets showed significantly higher contamination rates than those from Sham and Zinc markets. The study concluded that irrigation water and manure are potential sources of contamination, and lettuce may serve as a vector for pathogen transmission to consumers.

김혁수, 김영남, 김진원, 김계훈 · 한국토양비료학회지 · South Korea (Seoul)

This study investigated the physicochemical properties and heavy metal (Cd, Pb, Cu, Zn) contents in 21 urban agricultural soils in Seoul. The total heavy metal concentrations in these soils were found to be lower than the warning levels specified by the Soil Environmental Conservation Act of Korea for area 1. Phytoavailable concentrations of Cu, Pb, and Zn were also reported.

Marie-Christine Zélem, Zelem, Marie-Christine · AgEcon Search (University of Minnesota, USA) · Senegal (Dakar)

This study identifies numerous constraints hindering the widespread adoption of organic waste utilization in agriculture in the peri-urban area of Dakar, Senegal. These constraints include the nature, availability, and accessibility of organic waste, poorly controlled urbanization, effects of seasonal variation, resistance to changes, and medical risks. The project, which combines agriculture with city waste management, faces these challenges.

Siny Tsang, AM Holt, Eduardo Bessa Azevedo · Chronic diseases and injuries in Canada · Canada (Cobourg, Ontario)

This needs assessment in Cobourg, Ontario, interviewed food program clients to identify barriers to food access. Clients reported lack of transportation, insufficient food quantities, and inconvenient operating hours as barriers to using food programs. They also cited lack of available vegetables and fruit at home and income as barriers to consuming more produce.