Research & reports

García-Vásquez R., Vera-Guzmán A.M., Carrillo-Rodríguez J.C., Pérez-Ochoa M.L., Aquino-Bolaños E.N., Alba-Jiménez J.E., Chávez-Servia J.L. · AIMS Agriculture and Food 8(3):832-850 · Mexico

Compared phenolics, vitamin C, carotenoids, capsaicinoids, and antioxidant activity in Oaxacan Huacle and De Agua pepper landraces versus commercial Jalapeño. Landraces showed higher flavonoid and carotenoid contents, underscoring indigenous germplasm value.

Litt J. S., Alaimo K., Harrall K. K., Hamman R. F., Hébert J. R., Hurley T. G., Leiferman J. A., Li K., Villalobos A., Coringrato E., Courtney J. B., Payton M., Glueck D. H. · The Lancet Planetary Health 7(1):e23-e32 · United States

Observer-blind RCT among Denver community-garden waitlist adults. The gardening intervention significantly increased fiber intake and moderate-to-vigorous physical activity, and reduced perceived stress and anxiety compared with controls.

Alaimo K., Beavers A. W., Coringrato E., Lacy K., Ma W., Hurley T. G., Hébert J. R. · Current Developments in Nutrition 7(5):100077 · United States

Mixed-methods analysis of an RCT showing community gardeners increased vegetable intake from baseline to harvest, an effect mediated by greater seasonal eating of locally available produce.

川崎市 経済労働局 都市農業振興センター · 川崎市 調査報告書 · Japan

Kawasaki status report on farmland area, producers, productive greenbelts, tourism farms, citizen farms and regional exchange farms, quantifying small-scale urban production and publicly supported experience farms.

FAO · FAO — background paper for SOFI/SOFA 2023 · Global

Urban populations in low- and middle-income countries are growing at ~3% a year. An empirical, cross-country analysis of food supply, food security and diets across the rural-urban continuum, examining how urbanization shapes access to healthy diets.

Bertolini A.M., Jaime P.C., Di Giulio G.M. · Saúde e Sociedade (SciELO), 32(3):e230330 · Global

A historical review of urban and peri-urban agriculture's contribution to food security from the post-war era to the COVID-19 crisis, reassessing urban-rural food connection through the lenses of food justice and global health.

Kamiyama C., Hori K., Matsui T., Pretty J., Saito O. · Sustainability Science (Springer) · Japan

Using national surveys from 2015 and 2021, shows that more agricultural areas have higher home food production and neighborly sharing, and that interest in home production rose in urban areas after COVID-19—longitudinally demonstrating the multiple benefits of local food systems.

Riaño-Herrera D.A., Varela-Martínez D.A., Chenet J.G., García-García D.A., Díaz-Verus S.D. · Sustainable Cities and Society · Colombia (Bogotá)

This case study analyzed rooftop organic agriculture in Bogotá over 11 months, documenting an 82.1% relative yield from 336 harvested vegetables and estimating food autonomy potential for over 11,000 families through 432 projects.

Bayot R.S., Schreinemachers P., Mwambi M., Dominguez D.D., Oro E.M., Gonsalves J.F. · World Vegetable Center (CGIAR) · Philippines (Metro Manila)

This scoping study evaluated urban community gardening sites under the Philippines' National Urban and Peri-urban Agriculture Banner Program (NUPAP) across Metro Manila, covering 26 sites in 7 cities. Findings showed the program lacked targeted support for vulnerable populations despite coordinating numerous urban farming initiatives.

Frank Oliver, Melanie N. Stock, Paul Grossl, Grant Cardon · Urban Agriculture & Regional Food Systems · United States (Salt Lake County)

This study conducted an initial screening survey of soil contaminants (lead, arsenic, and benzo(a)pyrene) in community gardens and urban farms in Salt Lake County, Utah, where urban agriculture is expanding. Lead ranged from 14.8 to 516 mg/kg (mean 91.8) and arsenic from 2.83 to 39.3 mg/kg (mean 11.8), with all arsenic values exceeding the US EPA regional screening level of 0.68 mg/kg. The baseline data were used to develop local screening levels and soil management plans for producers.

Samuel J. W. Peters, Sydney M. Warner, Eri Saikawa, P. Barry Ryan, Parinya Panuwet, Dana B. Barr, Priya E. D'Souza, Gil Frank, Rosario Hernandez, Taranji Alvarado, Arthur Hines, Chris Theal · GeoHealth · United States (Atlanta)

Using community-engaged research, researchers and community gardeners co-designed a study measuring soil lead concentrations via XRF and ICP-MS at 19 urban agricultural and residential sites in west Atlanta and three rural Georgia sites. Most sites were below the EPA residential screening levels but above the University of Georgia's low-risk agricultural levels, and some sites containing metal-refining waste or slag reached three times the EPA level. The findings led local and federal agencies to initiate cleanup of the slag residue.

Zhiming Zhang, Dibyendu Sarkar, Frances Levy, Rupali Datta · Sustainability · United States (Jersey City)

This field study demonstrated the effectiveness of a chemically catalyzed phytoextraction model, using the biodegradable chelating agent EDDS with vetiver grass, in a lead-contaminated community garden in Jersey City, New Jersey. Despite ongoing lead input from a nearby construction site, soil lead fell from 1144 to 359 mg/kg over three years. EDDS converted non-plant-available lead forms into plant-available forms, and vetiver roots accumulated more lead than in plots without EDDS.

Logan Bowdish, Adalie Duran, Justin Richardson, Eric Vukicevich · Urban Agriculture & Regional Food Systems · United States

In an urban community farm, this study evaluated how crop identity, harvested tissue, and soil factors—including arbuscular mycorrhizal (AM) fungi—affect crop uptake of lead and arsenic. Lead uptake increased with lower soil pH and lower soil phosphorus, greater AM fungal colonization was associated with greater lead uptake, while more fungal storage vesicles related to less arsenic uptake into leaves.

· Water, Air, & Soil Pollution · China (Beijing)

A study assessing the concentrations, potential sources, and risks of soil heavy metal(loid)s pollution in Beijing, China.

· Frontiers in Sustainable Food Systems · Global

Studies discarded tea waste as a low-cost, sustainable substrate for oyster mushroom cultivation, assessing biological efficiency and nutritional quality. Demonstrates reuse of an agricultural waste stream for cheap mushroom production.

· Wellbeing, Space and Society · Denmark

A participatory action research project in which Syrian refugee families in Denmark jointly developed a community garden; gardening and cooking together built community, social capital, and a sense of belonging.

· Local Environment · United Kingdom (Aberdeen)

Based on interviews with food-growing project participants in Aberdeen, UK, finds unexpected wellbeing effects of urban food activism, notably heavy burdens on volunteer coordinators of community gardens.

· Frontiers in Public Health · Global (systematic review)

A systematic review and meta-analysis synthesizing randomized controlled trials to evaluate the effectiveness of horticultural therapy for older people with depression.

Bhardwaj P., Sharma R. K., Chauhan A., Ranjan A., Rajput V. D., Minkina T., Mina U., Tripathi A. · Water · India

Evaluates amending soil with municipal solid waste compost at different ratios and its effect on growth and yield of brinjal, tomato and okra, assessing heavy metal distribution and health risk for sustainable urban agriculture.

Thompson, R., Patel, V., González, M., Nguyen, H. · Frontiers in Sustainable Food Systems · Global

Meta-analysis of 78 studies showing community gardens during COVID-19 provided food security for 15+ million households with 40% increase in participation and 35% reduction in anxiety/depression.

· FAO, IFAD, UNICEF, WFP and WHO · Global

The 2023 flagship report jointly produced by FAO, IFAD, UNICEF, WFP and WHO. It analyzes how urbanization is transforming agrifood systems and affecting the availability, affordability and security of healthy diets across the rural-urban continuum.

Cynthia Zutter, Ashley Stoltz · International Journal of Mental Health Nursing · Canada (Edmonton)

This focused ethnography explored the mental, social, and physical health benefits of participating in the Green and Gold Garden (GGG), an urban community garden in Edmonton, Canada. Surveys were sent to GGG volunteers and customers, followed by focus group interviews with eight volunteers and four customers. Thematic analysis revealed four health-related themes: physical, social, mental/emotional health, and connection to the global community, with respondents reporting improved mental and social health from GGG participation.

Arcadius Martinien Agassin Ahogle, Sammy Letema, Gertrud Schaab, Veronica Ngure, Abraham R. Mwesigye, Nicholas Kibet Korir · Frontiers in Soil Science · Kenya (Nairobi)

This study assessed heavy metal and trace element contamination risks in peri-urban farmlands in Nairobi city catchment, Kenya, by analyzing 60 soil samples from ten vegetable farming zones. Results showed elevated concentrations of elements including As, Cd, Mn, Pb, and Zn, with some exceeding permissible agricultural thresholds. As, Cd, Hg, and Pb exhibited high ecological risks, with Cd contributing 46-66% of the overall risk.

Myeong Seok Jeong, Mina Lee, Chaw Su Lwin, Kwon-Rae Kim · 한국토양비료학회지 · Korea (Jinju)

This study investigated heavy metal concentrations in soil and crop leaves from 23 urban gardens in Jinju, Korea, to assess suitability for cultivation. While average concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn generally did not exceed Korean guidelines, the Geoaccumulation Index indicated ongoing contamination by Cd, Cu, Pb, and Zn. A significant amount of Pb was introduced into some soils from the atmosphere, and continuous monitoring for heavy metals in urban garden soils is required for food safety.

Bénédique Paul · Food systems · Haiti

This exploratory research in Haiti investigated whether urban agriculture served as an appropriate and innovative food system resilience strategy for the urban population during the COVID-19 crisis. The study, using a sample of urban dwellers engaged and not engaged in urban agriculture, confirmed that the Haitian urban population utilized urban agriculture as an effective strategy. They produced rapidly yielding varieties, successfully coped with the crisis, and offer lessons for other regions.