Research & reports

Juan Camilo Ochoa Céspedes · Entorno Geográfico · Colombia (Medellín)

This paper critically analyzes peri-urban and peri-urban agriculture, addressing problems of territorial tension resulting from the accelerated expansion of real estate into peri-urban areas due to low urban land availability. The discussion questions the economic, environmental, and social risks of this expansion, highlighting tensions and resistance. The paper illustrates these issues with examples from the peri-urban area of Medellín and its metropolitan area.

CHRISTINA FELIX KIFUNDA · Asian Journal of Agriculture · Tanzania

Combining 30 years of temperature and rainfall data from the Tanzania Meteorological Agency with a questionnaire survey of 386 urban-agriculture households across five wards of Kinondoni City (Bunju 118, Kunduchi 42, Mabwepande 102, Mzimuni 28, Wazo 96), plus focus group discussions, key informant interviews and direct observation, this study examined climate change's effects on urban crop production and farmers' adaptation strategies. More than 70% of surveyed smallholder farmers were aware of climate change indicators, consistent with the meteorological data, citing rising temperature (76%) and declining rainfall (73%); pests and diseases were ranked highest (88%) among significant climate-change effects. Land scarcity was also identified as a significant challenge for urban agriculture, and pesticide and fertilizer use was the most commonly cited adaptation strategy (65%).

Luiza Vigne Bennedetti, Paulo Antônio de Almeida Sinisgalli, Maurí­cio Lamano Ferreira, Fabiano Lemes de Oliveira · International Journal of Environmental Research and Public Health · Global

Following the PRISMA protocol, a 2023 systematic review evaluated 26 studies on the interplay between urban agriculture (UA) and sustainability surveyed on Web of Science. While UA is increasingly recognized as an action to promote urban sustainability and inform public health policy for urban populations, the review confirms that its implementation still presents challenges in countries across both the Global North and Global South. The review identified numerous key challenges to UA adoption, including air and soil contamination, availability of green areas, layout of urban infrastructure, and food distribution, among others. Given the many socio-economic and environmental contextual factors involved — especially when comparing Global North and Global South realities — the review concludes there is a need to develop a model adaptable to these different contexts. It further concludes that the concept of sustainability lacks a universal understanding, and that one of the most important remaining gaps is addressing social issues in relation to environmental ones.

Mahir Yazar, Ece Baykal Fide, İrem Daloğlu Çetinkaya · Journal of Environmental Policy & Planning · Turkey

A 2023 study of climate policies in nine cities in Turkey examined how vulnerable groups and individuals are identified and how land-use policy is developed to address the identified vulnerabilities and climate justice concerns, using policy content analysis and expert interviews. The analysis found critical relationships between identified vulnerable groups, responsive land-use policy and climate justice. While social-aid municipalism-related vulnerabilities dominated districts' climate policies, nature-based solutions (NBS) — especially green infrastructure and urban agriculture — emerged as the dominant climate adaptation approach. However, the way urban vulnerabilities are prioritized in the climate and sustainability plans places less emphasis on intersectionality and infrastructure-related vulnerabilities, and tokenism of justice occurs in the policy documents: the plans do not incorporate vulnerable communities into land-use planning. The study concludes that the complexity of responsive land-use policy requires greater awareness of how to practically support vulnerable communities.

Cole Rosengren · Waste Dive · United States

California's Little Hoover Commission recommended pausing SB 1383, the state's organics recycling law, citing concern the state will miss its 2025 targets, but CalRecycle, industry and environmental advocates strongly opposed the pause, noting roughly $500 million already invested. 445 of 614 jurisdictions now have residential food-waste collection programs, and waste costs rose 20% for residential and 30% for commercial customers.

Li Jiacheng · Eco-Business / Dialogue Earth · China

China's mandatory waste-sorting policy, launched in Shanghai in 2019, improved diversion and recycling but created a new problem: overbuilt waste-to-energy incineration capacity. Shanghai diverted 54% of its waste (6.46 million tonnes) in 2021, up from 21% in 2018, while the number of national incinerators grew from 130 in 2011 to 927 by 2023, pushing 2022 national overcapacity to 100.99%.

Joshua Newell, Alec Foster, Mariel Borgman, Sara Meerow · Cities · United States (Detroit)

A study in Detroit's Lower Eastside (~15 sq. miles) examined the spatial extent, characteristics, and residents' perceptions of urban gardens using spatial analysis and interviews. Gardens covered less than 1% of vacant land and were often ephemeral. Primary obstacles to scaling up urban agriculture in Detroit include uncertainty over land tenure, environmental pollutants, potential ecosystem disservices, and a lack of government support and capital investment.

Andrea Fantini · Agroecology and Sustainable Food Systems · Global

This paper analyzes the functions of urban and peri-urban agriculture (UPA) as a strategy for sustainable and resilient urban food systems and for coping with global emergencies. It identifies various functions of UPA and how they connect, but also discusses obstacles to its large-scale implementation. The paper highlights that despite its potential, significant barriers hinder UPA's widespread adoption.

Angelica Mendoza Beltrán, Kelzy Jepsen, Martí Rufí-Salís, Sergi Ventura, Cristina Madrid‐López, Gara Villalba · The Science of The Total Environment · Spain (Barcelona)

This study mapped N2O emissions from peri-urban agriculture in the Metropolitan Area of Barcelona (AMB), Spain. Researchers spatially distributed factors like crop type, fertilizer use, and irrigation, creating N2O emission maps using crop-specific and Tier 1 IPCC emission factors (EFs). The study found that Tier 1 IPCC EFs estimated 15% more emissions (7718 kg N2O-N year−1) than crop-specific EFs (6533 kg N2O-N year−1) for the entire AMB, indicating higher emissions for rainfed crops with Tier 1 EFs and for irrigated horticultural crops with crop-specific EFs. The mapping helps evaluate spatial variability of key factors but carries uncertainties due to downscaling regional data.

Grace Ning Yuan, Gian Powell B. Marquez, Haoran Deng, Anastasiia Iu, Melisa Fabella, Reginald B. Salonga, Fitrio Ashardiono, Joyce A. Cartagena · Heliyon · Global

This review examined urban agriculture (UA) across technology, socio-economy, and policy, noting that supporting UA expansion in cities is challenging due to its poor economic profitability. The study highlighted UA's value beyond profitability, including social, health and well-being, disaster risk reduction, and environmental benefits. It also presented advancements in UA technologies and plant biotechnology as potential solutions for increasing the future profitability of commercial UA.

Fa Likitswat, Alisa Sahavacharin · Journal of Architectural/Planning Research and Studies (JARS) · Thailand (Bangkok)

This research analyzed landscape transformations, specifically agricultural landscape structures and functions, in eight selected sites in the urban fringe of Bangkok from 1952 to 2018. The study found that the significant loss of agricultural landscape in Bangkok's peri-urban areas resulted in the loss of seasonal water retention areas, productive landscapes, and urban wildlife habitats. It concludes there is a research gap regarding the lack of policies and practices to promote ecosystem services linked to preserving peri-urban agriculture in Bangkok.

Elizabeth Regier, Walter McDonald · Journal of Sustainable Water in the Built Environment · United States (Milwaukee)

This study monitored two bioswales treating runoff from an urban farm in Milwaukee, WI, United States, to assess their hydrologic and water quality performance. The bioswales effectively reduced runoff volume, peak flows, total phosphorus, and high concentrations of total suspended solids (TSS >25 mg/L), achieving a median 98% load reduction across all pollutants. However, they showed mixed results in reducing total nitrogen concentrations and TSS at low influent concentrations (≤25 mg/L).

Bethuel Sibongiseni Ngcamu · Environmental & Socio-economic Studies · Africa

This literature review explored the effects of urbanization on food security in Africa by reviewing eleven empirical journal articles. Findings indicate that rapid, unplanned urbanization has led to increased food insecurity, environmental degradation, and unsustainable food security, exacerbated by ill-prepared and incompetent governments. Key issues identified include poor government interventions, inadequate land-use planning, and high incompetency among urban planners.

Angelica Mendoza Beltrán, Roc Padró, María José La Rota-Aguilera, Joan Marull, Matthew J. Eckelman, Jacob Cirera, Annalisa Giocoli, Gara Villalba · The Science of The Total Environment · Spain (Barcelona)

This study implemented an attributional, regionalized, cradle-to-gate life cycle assessment (LCA) to assess 14 environmental impacts of peri-urban agriculture (peri-UA) in the Metropolitan Area of Barcelona (AMB). It found that vegetables and greenhouses, the prevalent peri-UA land uses, had the largest assessed impacts among all peri-UA land uses. European NPK mineral fertilizer production to cover nitrogen demand for these crops drives all impacts. For fruit crops, on-site nitrogen emissions drive marine eutrophication impacts, and for irrigated herbaceous crops, phosphate runoff drives freshwater eutrophication impacts.

Stella Kabiri, Molly Allen, Judith Tomma Okuonzia, Beatrice Akello, Rebecca Ssabaganzi, Drake N. Mubiru · Open Research Africa · Uganda

This study investigated the extent of wetland loss and encroachment by urban agriculture in Wakiso and Kampala, Uganda, over 30 years from 1986 to 2016. Using field surveys, Landsat, and MODIS NDVI data, the analysis found that 72,828 ha (73%) of Wakiso-Kampala wetlands were lost, while agricultural areas doubled. Of this, 16,488 ha (23%) were converted from wetlands, with all cultivated agriculture in Kampala occurring in wetlands and 73% in Wakiso.

Zihao Chen, Lin Guo, Zilong Zhang · Highlights in Science Engineering and Technology · China (Shenzhen)

As urbanization accelerates in China, urban green space is becoming increasingly insufficient. This study analyzed Shenzhen's current three-dimensional greening policies and compared them with those of advanced foreign cities. The findings revealed three problems in Shenzhen's policies: a small scope of application, a lack of planning elements, and a low degree of compulsion. The paper proposes improvement solutions and optimization suggestions based on the governance experiences of other cities to address these shortcomings.

Swarna Devi Palanivelu, Nur Amira Zainul Armir, Amalia Zulkifli, Ainul Hafiza Abdul Hair, Kushairi Mohd Salleh, Keith Lindsey, Muhamad Hafiz Che Othman, Sarani Zakaria · Polymers · Global

This review discusses the potentials and limitations of hydrogel in urban agriculture. While hydrogel has been introduced in urban agriculture over the past few decades, its application is still being explored regarding hydrogel types, structure, physical and chemical properties, changes due to external factors, and suitability for different plant species. The study presents the current state of knowledge on hydrogel production methods, characteristics, advantages, and limitations.

Bernardino Bernardo, Elisa Eda Nhambire, Alice Castigo Binda Freia, Octávio Manuel de Jesus, José Júlio Júnior Guambe, Zacarias Alexandre Ombe, Gustavo Sobrinho Dgedge · Cadernos de Geografia · Mozambique (Maputo)

This mixed-method study analyzed the impacts of hailstorms on urban horticulture in northern Maputo City and Matola, Mozambique, following a storm on June 1, 2021. The study found total and partial destruction of ready-to-cut vegetables, including cabbage, lettuce, and onions, across all production areas. This resulted in heavy financial losses for farmers and a significant increase in vegetable prices in local markets.

Axel Prestes Dürrnagel, Matias Siueia Júnior, Simone Prestes Dürrnagel · Boletim GeoÁfrica · Mozambique

In Maputo, Mozambique's capital, urban agriculture is at a critical point, with accelerated urban growth and climate change impacts increasingly compromising agricultural spaces. A qualitative case study focusing on farmer associations in the urban district of KaMavota indicated that horizontal relationships among farmers enable information sharing and social capital creation. Conversely, vertical relationships between farmers and the government primarily promote knowledge exchange and competencies related to agricultural extension and land rights allocation.

Monika Egerer, Brenda B. Lin · CABI Reviews · Global

This review evaluated ecosystem services (ES) within urban agriculture (UA) systems and the trade-offs between these services. Urban agriculture provides many benefits and environmental services such as food provision, social cohesion, and climate regulation. However, it was shown that management decisions can create trade-offs between ecosystem services, where an increase in one service may potentially reduce the system's ability to provide another service at a desired level.

Abdulaziz I. Almulhim, Patrick Brandful Cobbinah · International Journal of Sustainable Development & World Ecology · Saudi Arabia

This article reviews literature on urbanization and its implications for the urban environment in Global South cities, discussing eight implications of the urbanization-environmental conundrum with cases from Saudi Arabian cities. Findings indicate that the sustainable development agenda in Saudi Arabian cities is skewed towards socio-economic development with limited focus on environmental issues. This situation is threatening the sustainability of rapidly urbanizing cities.

Petr Klusáček, Stanislav Martinát, Klára Charvátová, Josef Navrátil · Land · Europe

This study investigated the drivers of de-agrarianization in post-socialist cities, using Brno, Czech Republic, as a case study through qualitative interviews. It found procedural issues in preserving architectural heritage during the redevelopment of a former Cistercian monastery site, often resulting in only fragments being preserved. The research also demonstrated a decline in the use of urban agricultural properties, which are rapidly transformed into new urban environments under intense urbanization pressures.

Elvis Albert Robe Wandscheer, Rosa Maria Vieira Medeiros · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · Brazil

This study investigated the interrelations between urban agriculture and local institutions in Belém-PA and Porto Alegre-RS, Brazil. In both municipalities, actions were observed that were implemented temporarily but lacked continuity. Porto Alegre showed more commercial channels derived from previously established institutional relations, while Belém presented several elements without alternative solutions for problems related to high temperatures and navigation distances.

Denise Arroyo-Lambaer, Luís Zambrano, Miguel Rivas, Diana Laura Vázquez-Mendoza, Fernanda Figueroa, Martha B. Puente-Uribe, Ana Cecilia Espinosa‐García, Marco A. Tapia-Palacios, Marisa Mazari-Hiríart, Daniel A. Revollo-Fernández, Alaíde Jiménez-Serna, Marco Covarrubias, Carlos Sumano · Frontiers in Sustainable Cities · Mexico (Mexico City)

This study investigated the needs and commercialization challenges of chinampa producers in Xochimilco, Mexico City, to assess the potential of a green label. The analysis, based on a literature review and producers' mental model analysis, found that unresolved issues like commercialization problems, consumers' unwillingness to pay fair prices, soil degradation, and poor irrigation water quality persist. These issues make it difficult for most producers to bear certification costs, indicating that implementing a green label would likely fail to deliver its intended benefits.

Arnim Wiek, Stefanie Albrecht · Urban Agriculture & Regional Food Systems · United States (Phoenix)

A multiyear transdisciplinary project in Phoenix, United States, analyzed the development of a sustainable urban food forest enterprise. The project built a coalition of supporters, secured a suitable site, codeveloped a vision and action plan, and fundraised a major start-up donation. However, research findings indicate that despite achieving success factors to some extent, an underdeveloped sustainable entrepreneurial ecosystem jeopardizes long-term success and multiplication efforts.