Research & reports

Pascale Joassart‐Marcelli, Fernando J. Bosco · · United States (San Diego)

The alternative food movement (farmers' markets, community gardens) in San Diego, United States, was investigated in relation to gentrification. Uneven urban food landscapes were shown to be intimately connected to gentrification processes, shaped by race, class, political decisions, and capital flows. Farmers' markets and community gardens are primarily located in affluent and gentrifying areas, providing evidence of a growing appropriation of alternative food spaces by urban developers and cultural elites.

Pepijn Schreinemachers, Dhruba Raj Bhattarai, Giri Dhari Subedi, Tej P. Acharya, Hsiao-pu Chen, Ray-Yu Yang, Narayan Kaji Kashichhawa, Upendra Dhungana, Gregory C. Luther, Maureen Mecozzi · Journal of Development Effectiveness · Nepal

This study evaluated the combined impact of school gardens and nutrition education on 10- to 15-year-old schoolchildren in Nepal, using a cluster randomized controlled trial with 1275 students (2014) and 785 students (2015). After one year, significant improvements were observed in children's awareness of fruits and vegetables, knowledge of sustainable agriculture, food, nutrition, and health, and stated preferences for eating fruits and vegetables. However, these improvements in intermediary outcomes did not translate into significant improvements in fruit and vegetable consumption or nutritional status.

Devon A. Mihesuah · American Indian Culture and Research Journal · United States

In Oklahoma, tribes have initiated numerous food projects over the past three decades aimed at achieving food sovereignty. However, Oklahoma's complex history, environmental issues, and current politics present challenges such as uneven food quality, poor indigenous health, intratribal factionalism, racism, and a stark dichotomy of affluence and extreme poverty. These factors complicate the creation of self-sufficient food systems and the reconnection of tribal members with traditional foodways.

Abdul Rahman Conteh, Alusaine Edward Samura, E. L. S. Hinckley, Osman Nabay, Mohamed S. Kamara · Journal of Agricultural Science and Practice · Sierra Leone (Freetown)

This study was conducted to identify the risks of heavy metal contamination in urban and peri-urban cropping systems in Sierra Leone. Soil and plant samples were collected from 72 sites in Freetown and Bo and analyzed for Zn, Cu, Cr, Ni, Pb, and Cd. Heavy metals were detected across all sites, and some mild risk of cadmium toxicity was observed in densely populated areas of Freetown, though this was not reflected in plant uptake of cadmium.

Seyedardalan Ashrafzadeh, Niklas J. Lehto, Gareth Oddy, Ron G. McLaren, Ling‐Fen Kang, Nicholas Dickinson, Johannes Welsch, Brett Robinson · Applied Geochemistry · New Zealand (Christchurch)

A study in Christchurch, New Zealand, measured heavy metal (HM) concentrations in suburban garden soils and soils at risk of HM contamination due to former land uses or nearby activities. HM concentrations in suburban garden soils were higher than normal background levels, with 46% of urban garden samples exceeding the residential land use national standard for lead (210 mg kg−1), and the most contaminated soil reaching 2615 mg kg−1. Arsenic and zinc also exceeded national standards in 20% of soils. These findings suggest that soil HM concentrations should be key criteria when determining future land use for former residential areas demolished due to the 2010 and 2011 earthquakes, and that redeveloping these areas as parklands or forests would result in less human HM exposure than agriculture or community gardens where food is produced and bare soil is exposed.

Dorothy Menefee, Ganga M. Hettiarachchi · · United States

Soil contamination with potentially toxic trace elements and anthropogenic organic pollutants is a widespread problem in urban areas worldwide. While urban agriculture increases food security, potential risks exist without knowledge of urban soil contamination. Lead (Pb) contamination is a widespread and common urban soil issue associated with human health risks, with almost half of US EPA Superfund sites having Pb contamination. Cadmium (Cd) is also a widespread urban soil pollutant, largely from industrial activities like plastic manufacturing, battery disposal, and metal ore processing. The bioavailability of soil Pb to humans is unusually low and generally tied to Pb speciation.

Gabin Korbéogo · Environment and Urbanization · Burkina Faso (Ouagadougou)

This article explores how land tenure, water flows, and water quality are legally, politically, and socially framed in urban agriculture in Ouagadougou, Burkina Faso. Urban agriculture serves as a revenue source and a socio-political arena involving state representatives, experts, and farmers. Public authorities monitor legal standards for water use and hygiene, while farmers strive for efficient resource use, sometimes challenging official norms. These competing interests lead to conflicts over resource use or rule legitimacy, which are negotiated through institutional or informal bargaining.

Georgia Pollard, Philip Roetman, James Ward · Kobra (Universitätsbibliothek Kassel) · Australia (South Australia)

While urban agriculture is seen as a sustainable approach to improving food security, there is a significant knowledge gap regarding the financial accessibility of urban food production for all households. If urban agriculture remains primarily a middle-class discretionary activity, its role in city-wide food security improvement will be limited. This paper demonstrates that citizen science offers an effective approach to investigate the inputs (labor, costs, water use) and outputs (produce yields, value) of urban food gardens, using the Edible Gardens project in South Australia as an example.

Jason Byrne · · Global

Research on urban greenspace, including parks, gardens, and green infrastructure, consistently demonstrates that marginalized and vulnerable communities have less access to these areas. This chapter overviews environmental injustice research on urban greenspace, examining debates and challenges for researchers and policymakers, and highlighting issues like climate injustice and food insecurity related to environmental inequality.

Sertaç Güngör · Journal of Agricultural Faculty of Gaziosmanpasa University · Turkey (Konya)

This study investigated the current state of gardens in 7 nursery schools in Selçuklu district, Konya city, Turkey, regarding landscape design and space usage. The findings revealed that the nursery school gardens were not used effectively, lacked sufficient green space in their landscape design, and were not properly designed to contribute to children's mental and physical development.

Zane Vincēviča–Gaile, Dāvis Varakājs · · Latvia

This study aimed to determine the concentration of potentially toxic elements (Cd, Cr, Cu, Fe, Ni, Pb, Zn) in berries grown in allotment gardens in Rīga city, Latvia. Samples of raspberries, strawberries, red currants, black currants, gooseberries, and cherries were analyzed using atomic absorption spectroscopy. The results showed significant variability of element concentration among the berry species, with mean concentrations for Ni at 0.54 mg/kg, Pb at 0.20 mg/kg, Cr at 0.10 mg/kg, and Cd at 0.03 mg/kg.

Bethany B. Cutts, Jonathan London, Shaina Meiners, Kirsten Schwarz, Mary L. Cadenasso · Local Environment · Global

This paper applies a dynamic spatial politics framework to interpret a 30-year conflict over an urban garden in Sacramento, California. It examines how urban gardens, often idealized, are also sites of conflict due to competing visions of "soil" versus "dirt." The study highlights that contaminants like lead in the soil contribute to this instability, reframing fertile soil as dangerous dirt, and influencing the garden's transformation from a countercultural space to a gentrified amenity.

Eileen Bogweh Nchanji, Imogen Bellwood‐Howard, Nikolaus Schareika, Takemore Chagomoka, Johannes Schlesinger, D. Rodríguez Torres Axel, Glaser Rüdiger · International Journal of Agricultural Sustainability · Ghana (Tamale)

An ethnographic study in Tamale, Northern Ghana, assessed the sustainability of urban vegetable production between 2008 and 2014. While urbanization increased cultivation of profitable vegetables like cabbage, the practice involved irrigation with grey and wastewater and high pesticide use, posing health and environmental hazards. Industrial growth reduced open space urban agriculture by 8.7%, leading farmers to use interstitial spaces and peri-urban fringes, indicating a dynamic but not yet sustainable production system.

Sydney Giacalone · Journal for Undergraduate Ethnography · United States (Boston)

This ethnographic study, conducted in Boston and Somerville in the summer of 2016, investigated how urban chicken keeping might transform keepers’ thinking about food systems and animal relationships. The research revealed the unexpected discovery of lead contamination in urban chicken flocks in the Boston area, which unsettled the imagined simplicity of urban agriculture and exposed a "metabolic rift." This finding prompted keepers to engage more deeply with the history of the soil and opened new ways of thinking about collective metabolism, multispecies living, and food politics.

Norbert Becker, Stefanie Schön, Alexandra‐Maria Klein, Ina Ferstl, Ali Kizgin, Egbert Tannich, Carola Kuhn, Björn Pluskota, Artur Jöst · Parasitology Research · Germany

The first mass development of Aedes albopictus, likely introduced by trucks from Italy, was confirmed in an allotment garden area in Freiburg, Southwest Germany, in 2015. Surveillance confirmed a high infestation, with the container index exceeding 30% in August 2015. Control measures, including citizen awareness, environmental management, and Bacillus thuringiensis israelensis (Bti) tablets, successfully reduced the Aedes albopictus population, with the number of gardens without containers increasing from 17% to 35% by September 2015.

Ojuolape F. Akande, S. A. Ajayi · International Journal of Environment Agriculture and Biotechnology · Nigeria

This study measured heavy metals (As, Cd, Cu, Pb, Zn) in soil and in amaranth (Amaranthus hybridus) and jute mallow (Corchorus olitorius) vegetables from selected peri-urban farms around Osun State, Nigeria, to assess human health risk. Soil concentrations fell within FAO/WHO (2002) and EU (2006) agricultural background ranges, but vegetable samples showed appreciable metal levels; arsenic was below detection in all samples, amaranth showed higher retention than jute mallow for all metals except copper, the transfer-factor order was Cd > Zn > Pb > Cu, amaranth contributed the highest estimated daily intake for Cd, Cu, Pb and Zn, the health risk index was high for Cd and Pb but low for Cu and Zn, and the hazard index results indicate that vegetables grown on the selected peri-urban farms are not safe for consumption.

Elizabeth A. Miernicki · Illinois Digital Environment for Access to Learning and Scholarship (University of Illinois at Urbana-Champaign) · United States

A study from the University of Illinois at Urbana-Champaign, USA, that identifies soil contamination as a universal concern in urban agriculture and notes that the long-term benefits of alternative soil management systems such as raised beds have not been explored in the scientific literature. Its stated objective is to determine the effects of six soil management options - direct soil with synthetic fertilizer (DSF), direct soil with organic amendments (DSO), raised-bed mixture with synthetic fertilizer (RBMF), raised-bed mixture with organic amendments (RBMO), raised-bed compost-only with synthetic fertilizer (RBCF), and raised-bed compost-only with organic amendments (RBCO) - on yield of kale, garlic, pepper, cilantro and radish, on soil biological, chemical and physical properties, and on ecosystem services such as water and nutrient retention. Data collected include marketable versus cull yield, soil nutrients and organic matter, soil moisture, weed emergence, infiltration rate and bulk density, but this abstract does not report the comparative results themselves.

Katyelle Rafael, Ariella Andrade Marchioro, Cristiane Maria Colli, Bruna Tiaki Tiyo, Fernanda Ferreira Evangelista, Renata Coltro Bezagio, Ana Lúcia Falavigna-Guilherme · Transactions of the Royal Society of Tropical Medicine and Hygiene · Brazil

This study genotyped Giardia duodenalis in raw-eaten vegetables (crisp lettuce, regular lettuce, kale, chicory, and rocket) sampled from street markets and community vegetable gardens in an urban area of southern Brazil. Researchers analyzed 130 samples from street markets and 130 from community gardens (260 total), washing them in Tween 80 solution, filtering through a cellulose acetate membrane, amplifying the GDH gene by semi-nested PCR, and genotyping positive samples by PCR-RFLP. 7.3% (19/260) of samples tested positive for G. duodenalis, from both street markets (10/130) and community gardens (9/130), including both organic and non-organic products. Assemblage AI predominated, but assemblages B and E, which carry zoonotic potential, were also found. The study concludes this points to a need for investigating commercially sold raw vegetables and establishing stricter quality control.

Richard Blaustein · BioScience · United States

Against a backdrop of heightened concern about lead exposure following the lead-contaminated water supply in Flint, Michigan, a review examines prior research on whether sunflowers (Helianthus annuus) can remove lead from urban garden soil through phytoextraction, in which plants draw contaminant metals up into their shoots. Some preliminary studies suggested sunflowers could phytoextract lead, but more extensive research has been disappointing; adding the chelating agent EDTA raises lead's solubility and plant uptake but is expensive and only meaningful combined with other practices such as compost application. Retired USDA scientist Rufus Chaney states that, unlike successful cases such as alpine pennycress extracting cadmium or canola extracting radioactive cesium, no serious study supports significant lead phytoextraction.

Gideon Aghaindum Ajeagah, Chumtchoua Armel Landry, Mbouombouo Mama, Foto Menbohan Samuel, Thomas Njiné · Journal of Applied Biosciences · Cameroon

In lowland areas of Yaoundé, Cameroon, where wastewater is used for market gardening, water samples were collected from November 2013 to April 2014, with identification and bio-statistical analysis conducted in 2015-2016. Flagellated protozoan cysts, identified via Lugol staining after zinc-sulfate flotation concentration, were found at average densities of 101±70 cysts/L for Giardia intestinalis, 34±20 cysts/L for Chilomastix mesnili, 3±6 cysts/L for Retortamonas intestinalis, and 1±3 cysts/L for Enteromonas hominis, with the highest densities recorded during the short rainy season (172±108 cysts/L). Cyst density was significantly correlated (P≤0.05) with physico-chemical parameters including suspended solids, oxidizability, and turbidity. The study concludes that vegetables grown with this wastewater must be well washed, disinfected, and thoroughly cooked before consumption to reduce health risks.

Oscar Díaz Rizo Susana Olivares Rieumont · Anales de la Academia de Ciencias de Cuba · Cuba

This study in Cuba used X-ray Fluorescence and Low-Background Gamma Spectrometry to analyze heavy metal and radioactive element concentrations in marine/fluvial sediments and urban soils. It found heavy metal contamination in coastal sediments of Guacanayabo Gulf, mercury bioaccumulation in oysters from Sagua River estuary, and possible selenium contamination in catfish tissue. The study also reported, for the first time, heavy metal concentrations in urban soils of Havana, Moa, Las Tunas, and Cienfuegos, including in urban agricultural farms, evaluating their quality for urban farming and potential health impacts.

Catharine Ward Thompson, Peter J. Aspinall, Jenny Roe, Lynette Robertson, David Miller · International Journal of Environmental Research and Public Health · United Kingdom

A cross-sectional survey of 406 adults in four deprived urban communities in Scotland, UK, investigated the relationship between green space access and health outcomes. While the amount of neighborhood green space and access to a garden or allotment were significant predictors of stress, social isolation and place belonging were found to be the strongest predictors of stress in three communities and of poor general health in the least healthy community. Physical activity, winter green space visits, and home views also predicted general health.

E.J. Veen, Petra Derkzen, B.B. Bock, A.J. de Visser, J.S.C. Wiskerke · Sociologie · Netherlands

This case study of a community garden in the Netherlands, used by three different groups, found that communities formed in such gardens are complex and multiple, not singular. While the garden served as a meeting space for two groups, strengthening internal cohesion, both groups categorized people as 'us' and 'them' based on residence. This strengthened their social identities and led to struggles over garden ownership, demonstrating that shared presence does not necessarily bridge social distances.

Florence Chimbwanda · Journals & Books Hosting (International Knowledge Sharing Platform) · Zimbabwe (Masvingo)

This study investigated participants' attitudes and perceptions toward urban gardening in Mucheke town, Masvingo, Zimbabwe, using questionnaires, focus group discussions, and field observations with a sample of 40 participants. It found that urban gardening is important for the community and income generation, with participants reporting benefits like additional income, family consumption, and socialization. However, participants identified challenges including theft, dilapidated canals, a single water point, and limited market access.

Mónica M. Gerber, Jennifer L. Callahan, Danielle N. Moyer, Melissa L. Connally, Pamela M. Holtz, Beth M. Janis · International Perspectives in Psychology · United States

This exploratory mixed-methods study investigated the perspectives on community gardening among Nepali Bhutanese refugees (N=50; 62% female) in the United States, comparing gardeners (n=22) and non-gardeners (n=28). Quantitative results showed no significant differences between groups regarding symptoms of depression, anxiety, somatic complaints, or adjustment to life in the US. However, community gardening was significantly positively associated with social support, a finding further supported by qualitative data.