Research & reports

Peter Sanjo Adewale, Sunday Clement Olubunmi Makinde, V. Kusemiju, Olawole O. Obembe · Journal of sustainability and environmental management · Nigeria

This study measured and compared lead (Pb), cadmium (Cd) and manganese (Mn) concentrations in soil and leafy vegetables (Amaranthus hybridus, Celosia argentea, Corchorus olitorius) using atomic absorption spectrophotometry at Urban Expressway Farms (UEF) and Peri-urban Road Farms (PRF) in Lagos State, Nigeria. It found the highest Pb concentration (0.93+/-0.06) in Celosia argentea at UEF, and the highest Cd (0.51+/-0.11) and Mn (0.98+/-0.02) concentrations in Amaranthus hybridus at UEF, with Pb in Celosia argentea 5 m from the expressway and Cd in Amaranthus hybridus 10 m from the expressway exceeding WHO/FAO permissible levels; heavy metal residue levels were driven more by farm location than by vegetable type, and the study calls for regular monitoring to prevent consumption of contaminated leafy vegetables and recommends farmers cultivate fields farther from expressways.

Abdelkarim Hamrita, Daniel Ferrer Jiménez, Hichem Rejeb · Frontiers in Sustainable Cities · Africa

A 2022 study analyzed the peri-urban agrifood system of the Sousse urban agglomeration, one of the most important in Tunisia, from a landscape perspective. It finds that clearly deficient regulations combined with uncontrolled urban development, together with intersecting political, environmental and economic factors, are threatening the survival of a traditional, largely family-based agricultural model built on mixed or polyculture production with predominant olive groves — a model the study describes as vital to the economic maintenance of many families and to food security. Using the Landscape Character Assessment methodology, the study proposes a landscape-project tool to strengthen the resilience and sustainability of peri-urban agriculture and prevent the loss of landscape heritage. It also points to the importance of integrating green infrastructure into land-use planning and to the need to promote Agricultural Parks, a protected status already recognized in Spain and other countries, putting forward specific proposals for the Sousse peri-urban agricultural landscape while insisting on the need to reform current forms of governance.

Pu Xu, Shanwei Li, Xiaona Yang, Yufeng Li · Journal of Environmental and Public Health · China

Agricultural statistical data from Shanghai for 1998-2019 were analyzed using an Environmental Kuznets Curve and a VAR model to examine the relationship between urban agricultural nonpoint source pollution (UANSP) and rural residents' income growth. An inverted "N"-shaped curve linked plastic film application intensity to per capita disposable income, while fertilizer and pesticide application intensity showed a linear negative relationship with income. Nonpoint source pollution emissions declined as income rose, and while reducing this pollution supported short-term income gains for rural residents, it had a negative effect on their long-term income growth.

Ferdi Gultom, Sugeng P. Harianto · Jurnal Analisa Sosiologi · Indonesia

Using dependency theory, this literature study analyzes the decline of the agricultural sector in urban Indonesia, arguing that the government's focus on industrial-sector development, mediated through a central state-satellite relationship, has drawn in the modern sector at agriculture's expense, manifested in widespread conversion of urban agricultural land. Drawing on news sources and journals and analyzing data with the Miles and Huberman model, the study finds that the urban agricultural sector is fading as farmland is increasingly converted to industry, infrastructure and settlements, and that farmer regeneration has declined due to reduced interest in becoming a farmer.

Rahmad Hendra, Firdaus Firdaus, Samariadi Samariadi · UNIFIKASI Jurnal Ilmu Hukum · Indonesia

A descriptive qualitative study of land disputes between oil palm plantation companies and Indigenous communities in Bencah Kelubi and Subarak villages, Kampar Regency, Indonesia. In Subarak, the plantation investor applied the Free, Prior and Informed Consent principle (locally PADIATAPA) before investing and built a garden for the Indigenous community. By contrast, the other company covered in the study failed to honor its commitment to build community gardens and disregarded the PADIATAPA principle. The study concludes that applying PADIATAPA at the outset could substantially reduce conflict between plantation companies and Indigenous people.

Hae Jong Yang, Tae‐Woo Kang, Byungwoong Choi, Soon Hong Hwang, Dongseok Shin, Won-Pyo Park · Sustainability · South Korea

This study verified heavy-metal pollution levels in sediments of an urban-agricultural watershed in the Yeongsan River basin, South Korea, through evaluation of Sediment Quality Guidelines (SQGs), a pollution load index (PLI), and a potential ecological risk index (PERI), and analyzed statistical relationships between pollution levels, land use, and potential pollution sources. Pb, Zn, Cu, Cd, and Hg concentrations were highest at mid-upstream sites, while As, Cr, and Ni concentrations were similar across most sites. Sites showing potential toxicity to benthic organisms relative to SQGs were most frequently observed at mid-upstream, and PLI and PERI evaluations likewise confirmed high anthropogenic pollution and ecological risk there. Mid-upstream sites with high heavy-metal pollution correlated strongly with urban land use — the largest land-use category — indicating links to population density and industrial complexes; statistical analysis confirmed this relationship. The findings indicate that urban areas are highly likely to cause anthropogenic heavy-metal pollution of sediments via point and non-point sources such as domestic sewage and industrial wastewater.

Per-Anders Langendahl, Maria Tunberg, Suvi Kokko · · Europe

Smart urban agriculture — food produced in closed, controlled and digitally augmented environments such as vertical farms, plant factories and aquaponics systems — is found in cities worldwide and is said to produce fresh food year-round using fewer chemicals and fewer food miles. However, critiques of smart urban agriculture note it is a marginal activity that often produces food with low nutritional value and requires energy-intensive artificial lighting. Using qualitative research methods, this report examines the development of smart urban agriculture in Sweden, identifying experimental and entrepreneurial initiatives and analyzing them in relation to high-level policy agendas such as food policy, smart cities and digitalisation. The findings show Swedish smart urban agriculture broadly consists of technology-oriented entrepreneurial start-ups and experimental initiatives split into production-oriented (mainly herbs and leafy greens), community-oriented (prioritizing social benefits), and technology-oriented (developing and supplying digital solutions and services) types. However, product output was limited to a small variety of financially high-margin crops sold at premium prices. In relation to high-level strategic agendas, smart (urban) agriculture is recognized for environmental and social benefits such as mitigating flooding.

Michael Hardman, Andrew Clark, Graeme Sherriff · Agronomy · United Kingdom

Using a qualitative approach across the UK's largest urban farm and a range of other urban agriculture (UA) sites, this study examined the barriers to upscaling city farming. Evidence pointed to urban soil contamination and hesitation about growing crops in cities as a core issue preventing UA from scaling up, alongside public hesitancy and financial barriers, despite the practice's potential social, environmental and economic value through job creation, biodiversity enhancement and shorter food supply chains. The paper concludes that public hesitation, financial barriers and soil quality prevent development, and calls for a more pragmatic approach to these barriers.

Sandra Boatemaa Kushitor, Shawn Alimohammadi, Paul Currie · PLOS Sustainability and Transformation · South Africa

An ethnographic study using in-depth interviews and participant observation, conducted April to November 2020 with thematic analysis, examined the role of the informal food sector in food flows in Cape Town, South Africa, during the COVID-19 lockdown. The informal food sector has historically been subject to exclusionary urban policies, and lockdown regulations caused food flows through the sector to cease, resulting in job loss and increased food insecurity. The sector subsequently reshaped food flows through urban agriculture, food aid programmes and community change, though it can also hinder urban modernisation. The study concludes regulatory frameworks need to be more inclusive of the sector.

Felix Chari, Bethuel Sibongiseni Ngcamu · Climate · Africa

In Masvingo City, Zimbabwe, a structured questionnaire administered to urban livestock farmers, triangulated with in-depth interviews with livestock stakeholders, examined how climate change-related hazards affect the urban livestock industry. Heatwaves, floods and droughts were found to significantly harm the industry: farmers lose livestock to disease, poor pastures and extreme weather, while the hazards also damage storage and distribution of livestock products, labour supply and productivity, and the profitability of livestock enterprises. The study calls for further research on location-specific adaptation strategies.

Hadaro Hando Filmon, Alemu Legesse Mitke · African Journal of Agricultural Research · Africa

In Addis Ababa, Ethiopia, a household survey, interviews and case analysis of beneficiary women, using 10 indicators of women's empowerment in agriculture, assessed the effect of a program-based sustainable urban agriculture intervention. 80% of beneficiary women were empowered (to a score of 0.93), while the remaining 20% were not; disaggregating the "empowered" group by intersectional differences revealed further unintended negative impacts. While urban agriculture contributed to women's empowerment, the study found that a lack of tailored support and a uniform program approach excluded segments of women beneficiaries, and it calls for a rights-based approach and feminist gender analysis to address these intersectional barriers.

Danielle Purkiss, Ayşe Lisa Allison, Fabiana Lorencatto, Susan Michie, Mark Miodownik · Frontiers in Sustainability · United Kingdom

A citizen-science study invited 9,701 UK residents to test how biodegradable and compostable plastics actually degrade in home composting. Many items, including certified products, failed to fully break down; 60% of TUV OK Compost Home-certified items were still clearly visible afterward. The authors conclude home composting is not an effective or environmentally beneficial disposal method for these materials in the UK.

Bárbara Corneli Colombatto · enREDando · Argentina

Built around interviews with huerteros (urban gardeners), this piece presents both the achievements and the limits of Rosario's urban agriculture: 7 Park Gardens and 6 group gardens involving over 250 people, 25 hectares producing 2,500 tonnes a year, and a $250,000 international prize won in 2021. It also documents organizational fragmentation among gardeners, a lack of secure land-loan agreements (comodatos), the absence of sustained public investment matching the programme's international recognition, and unresolved conflicts with neighbors that the municipality does not intervene in. It cites a regional statistic that only 18% of farms in Latin America and the Caribbean are run by women.

Helen Toxopeus, Friedemann Polzin · Journal of Environmental Management · Global

A systematic review of academic literature identified key barriers and strategies for financing urban nature-based solutions (NBS), including urban agriculture. Two overarching barriers were found: a lack of coordination between private and public financiers, and difficulties in integrating NBS benefits into valuation and accounting methods. The review concluded that an integrated accounting and valuation framework for NBS is currently lacking, and strategies often focus on encouraging co-financing from private beneficiaries.

Barbara Sowińska-Świerkosz, Malwina Michalik-Śnieżek, Alicja Bieske-Matejak · Sustainability · Poland

This study analyzed the potential of allotment gardens (AGs) in Poland to be considered nature-based solutions (NBS), examining their use of green/blue infrastructure, problem-solving capabilities, benefits, and economic efficiency. The study identified institutional barriers, irregular distribution of benefits, and deficiencies in economic efficiency as significant obstacles. It concluded that AGs, while a type of unsophisticated NBS, have limited effectiveness.

Dominika Dymek, Agnieszka Wilkaniec, Leszek Bednorz, Magdalena Szczepańska · Sustainability · Poland

This study in Poznań, Poland, examined the significance of allotment gardens in the urban green space system and developed a classification method for urban planning. While over 30% of allotment gardens were found to be of high significance, urban planning documentation indicates plans to reduce their area. Even highly significant gardens are slated for liquidation, highlighting a conflict between their ecological value and current urban development plans.

Thulani Dube, Saziso Sibanda, Phibion Chiwara · Cogent Social Sciences · Zimbabwe (Bulawayo)

This study investigated farmers' perceived effects of climate change on peri-urban agriculture in Bulawayo, Zimbabwe, and their adaptation methods. Using a sample of thirty peri-urban plots, findings revealed that farmers perceived significant climatic changes negatively impacting their farming activities, including reduced precipitation, increased atmospheric temperature, and diminishing borehole yields. Adaptation methods included repeated planting, watering plants at night, renting animal space in other farms with more water sources, and purchasing supplementary feed for livestock.

Alba Canet-Martí, Rocío Pineda‐Martos, Ranka Junge, Katrin Bohn, Teresa A. Paço, Cecília Delgado, Gitana Alenčikienė, Siv Lene Gangenes Skar, Gösta F. M. Baganz · Water · Global

This paper examines nature-based solutions (NBS) for urban agriculture (UA) in circular cities, focusing on input/output streams. It identifies that the understanding of I/O streams for different NBS is insufficient to fully leverage their potential for strengthening circularity in UA. The study pinpoints gaps that hinder UA's development as an opportunity within the Circular City framework, emphasizing the need for a broader understanding of food-related urban streams.

Ambrogio Zanzi, Valentina Vaglia, Roberto Spigarolo, Stefano Bocchi · Land · Italy (Milan)

This study assessed the sustainability of eight agri-food start-ups in a peri-urban area of Milan, Italy, using the FAO's Sustainability Assessment of Food and Agriculture systems (SAFA) framework. The application of SAFA indicators revealed positive aspects but also some limitations typical of unstructured enterprises.

Chethika Gunasiri Wadumestrige Dona, Geetha Mohan, Kensuke Fukushi · Sustainability · Global

This systematic literature review analyzed 54 articles on urban agriculture, examining socio-economic context, agriculture models, opportunities, and challenges. The review found that academic literature favors community gardens in developed countries and gives comparatively less attention to identifying challenges, benefit groups, and government support for urban agriculture.

Carlos Tapia, Linda Randall, Shinan Wang, Luciane Aguiar Borges · Sustainable Cities and Society · Denmark (Aarhus)

This study presents a novel indicator-based evaluation framework for urban agriculture, tested in Fællesgartneriet Brabrand, a community garden in Aarhus, Denmark. The framework aims to capture the contribution of gardening practices to urban sustainability, acknowledging that urban agriculture may also have social and environmental externalities depending on prevalent farming practices.

Victoria Schoen, Chris Blythe, Silvio Caputo, Runrid Fox-Kämper, Kathrin Specht, Agnès Fargue‐Lelièvre, Nevin Cohen, Lidia Poniży, Konstancja Fedeńczak · Frontiers in Sustainable Food Systems · Global North

This 2021 paper, based on data collected in summer 2020 from five Global North countries (France, Germany, Poland, UK, USA), examined the effects of COVID-19 on urban farms and gardens. The pandemic presented multiple challenges, including loss of support services, lost income, and reduced output due to labor supply issues. It also created opportunities like new local markets and increased community cohesion, demonstrating how gardens adapted to become more resilient.

Susana Toboso‐Chavero, Cristina Madrid‐López, Gara Villalba, Xavier Gabarrell, Arne Björn Hückstädt, Matthias Finkbeiner, Annekatrin Lehmann · The International Journal of Life Cycle Assessment · Global

A comprehensive environmental and social life cycle assessment of perlite, peat, and coir growing media, imported to Spain from Turkey, Germany, and the Philippines respectively, was conducted for urban rooftop farming. Environmentally, coir had the lowest burden, while perlite had the highest impacts due to mining and transport. Socially, peat performed best, but coir showed the worst scores in community infrastructure and human rights, and perlite performed lowest in health and safety.

Christina Ergas · · Cuba

This chapter examines Cuba's urban agricultural food production, which developed through top-down government initiatives that later decentralized and subsidized local efforts in response to resource scarcity. While Cuban urban farmworkers' cooperatives enable local residents to sell produce at low costs, the program still faces social environmental stumbling blocks despite its successes in achieving high human development with a small ecological footprint.

Bruno do Nascimento Macedo, Fernanda Nogueira Comas, Amarílis Lucia Casteli Figueiredo Gallardo · Journal of Urban Technology and Sustainability · Brazil (São Paulo)

This study discussed the main environmental services and disservices associated with urban and peri-urban agriculture (UPA) in São Paulo, Brazil, using a systematic literature review and spatial analysis. It identified 12 environmental services and 5 disservices, mapping 197 UPA initiatives. The research concluded that UPA has the potential to offer environmental benefits, but can also exert negative pressures on the environment, including in areas that should be protected.