Research & reports

Kinga Kimic, Magdalena Błaszczyk · Sustainability · Poland (Warsaw)

This study identified and assessed vegetable cultivation projects submitted to the Warsaw Participatory Budget (WPB) between 2015 and 2023. The research classified projects into six types and evaluated them across social, functional, ecological, and economic dimensions. The results showed that vegetable-related projects in the WPB were decidedly niche, with only 101 initiatives submitted and 31 implemented, primarily focusing on education for children rather than direct food access.

Marta Melon, Tomasz Dzieduszyński, Piotr Sikorski, Beata Joanna Gawryszewska, Maciej Lasocki, Arkadiusz Przybysz · Sustainability · Poland (Warsaw)

The capacity of Family Allotment Gardens (FAGs) in Warsaw, Poland, to provide air-pollution filtration and microclimate regulation was quantified. Particulate matter, air temperature, and relative humidity were measured inside and outside three allotment complexes in autumn 2023. Results showed a moderate reduction in PM concentrations inside gardens (by about 2 µg/m³) and slightly higher humidity (2.1%). However, the cooling effect was weak (less than 0.3 °C), indicating a limited spatial range under autumn conditions.

Evangelista et al. · Agronomy for Sustainable Development · Europe

This 8-year case study tracked tomato cultivation in a rooftop greenhouse. Peak yield reached 49 g plant−1 day−1 in the 2023 cycle, but overall yield declined by 31.2% across the 8 years. Best water use efficiency reached 36.8 g/L under reduced irrigation. Solar transmittance dropped from 50.9% in 2015 to 46.4% in 2023 due to polycarbonate degradation, and life-cycle global warming impact rose from a minimum of 0.54 kg CO2eq to 0.94 kg CO2eq in 2023.

Juliane Forßmann, Simon Goebel · Zeitschrift für Flüchtlingsforschung · Germany

An urban gardening project in a residential facility for up to 230 refugees in Germany aims to counteract precarious living conditions. While the garden offers a low-threshold space for knowledge exchange on resource-saving cultivation, biodiversity, and health promotion, this paper also reflects on the project's limits.

Sergi Ventura, J.R. Armengol Miró, David Camacho-Caballero, Enric Casellas, Ricard Segura-Barrero, Alberto Martilli, gara villalba · Urban Climate · Spain (Barcelona)

This study used the Pseudo Global Warming method and WRF model to assess urban heat adaptation strategies in the Metropolitan Area of Barcelona. Three strategies were evaluated: increasing rooftop albedo, implementing irrigated sedum green roofs, and increasing peri-urban agriculture and urban parks. While increasing rooftop albedo provided the greatest daytime cooling (−1.75 °C), and green roofs and peri-urban agriculture showed moderate regulation, none of the strategies fully counterbalanced the projected 6 °C temperature increase by 2100, indicating a limited capacity of these adaptations under severe warming scenarios.

Holger Braun, Dorothee Apfel, Benedikt Rilling, Carsten Herbes · Cleaner and Responsible Consumption · Germany

A study with 44 hobby gardeners in Germany found that substrates are not a major part of gardeners' social interactions, and price is the dominant purchase criterion for substrates, with sustainability not playing an important role. Although basic knowledge about peat is widespread, purchasing substrates is a utility-driven process with mostly passive information behavior.

Jaume Vilasís Pamos, Pablo Aránguiz, Stefhania Lozano, Guillermo Palau Salvador · Revista Lecciones Vitales · Spain (Valencia)

This study examines urban agriculture initiatives in Valencia, Spain, which adopt an agroecological approach to promote sustainable practices like composting. While these collective strategies aim for sustainable agricultural models and contribute to food sovereignty, they face significant challenges, particularly regarding access to water. The initiatives also engage in political action and promote equitable organizational models.

Silvio Caputo, Victoria Schoen, Chris Blythe · Land · United Kingdom (London)

Data was collected from seven community gardens and one community farm in London, UK, during the 2019 and 2020 growing seasons using a citizen science approach, investigating crop yield, resource inputs, and social benefits. Results showed very mixed levels of crop and social productivity depending on organizational structure and agenda, with no clear pattern emerging. This study suggests that citywide productivity evaluations based on small data samples may not be reliable.

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).

Fabio Amato, Lucia Simonetti · Journal of urban regeneration and renewal · Italy (Naples)

This paper focuses on the social urban garden in the Ponticelli neighborhood on the eastern outskirts of Naples, Italy, an area facing significant social and cultural problems including high unemployment and crime rates. The urban garden demonstrates how social cohesion can be built through urban agriculture and contribute to sustainability. However, the initiative risks remaining isolated and providing limited benefit to regional environmental sustainability efforts if not framed within an overall metropolitan strategy.

Susana Toboso‐Chavero, Cristina Madrid‐López, Xavier Gabarrell, Gara Villalba · Environmental Research Communications · Spain (Barcelona)

Implementation strategies for food-energy-water production systems on urban rooftops were evaluated in a typical housing estate in the Metropolitan Area of Barcelona, comprising 201 buildings and 13,466 inhabitants. Residents tended to choose strategies providing energy and water over the food production potential of rooftops. However, environmental assessment indicated that vegetable production alternatives were the least impactful, meeting 42-56% of residents' fresh produce demand and reducing environmental impacts by 24-37 kg CO2 eq m-2 per rooftop per year. This suggests residents were primarily concerned with energy expenses rather than food insecurity or social cohesion.

Martí Rufí-Salís, Felipe Parada, Verónica Arcas‐Pilz, Anna Petit‐Boix, Gara Villalba, Xavier Gabarrell · Frontiers in Plant Science · Spain (Barcelona)

This study investigated a closed-loop crop cascade system in a Barcelona rooftop greenhouse, using tomato leachates to irrigate five successive lettuce cycles. The results showed that low yields (below 130 g per lettuce plant) were obtained when the cascade system was used during the early stage of the donor crop, as the nutrient amount, especially nitrogen, was insufficient for the receiving lettuce crop. Additionally, electrical conductivity values became too high (near 3 dS/m) at the end of the donor crop cycle, indicating limitations in maintaining optimal conditions throughout.

Barbara Maćkiewicz, Raúl Puente Asuero, Antonio Garrido Almonacid · Quaestiones Geographicae · Spain

This study investigated how urban allotment gardens in Baeza, Andalusia, Spain, affect the city’s sustainable development. The research showed that allotment gardens in Baeza endorsed all three pillars of sustainable city development: ecological, economic, and social. However, it was found that developing broader community relations on the city scale, reviving the declining local grocery market, and disseminating environmental initiatives that allotment gardens could promote and facilitate were missing.

Andy Lockhart, Simon Marvin · Antipode · United Kingdom (Sheffield)

This article explored the phenomenon of automated environmental control, using three sites in Sheffield, UK: a botanical glasshouse, a luxury hotel, and a university plant growth research lab. The study identified technical and ecological tensions and limits of indoor environmental control at each site, which restrict the scope of automation. It also showed that maintaining desired conditions required considerable hidden labor and energy.