Research & reports

Stepan Svintsov, Prajal Pradhan, Taylor Smith, Diego Rybski · Sustainable Cities and Society · Europe

A systematic evaluation in 2018 assessed the potential for low-tech, open-air, soil-based urban vegetable production across 840 cities in 30 European countries. The study used geospatial, demographic, and climate data under three land-use intensity scenarios. It estimated that 4551–7586 km² of urban land could yield 11.8–19.8 million tons of vegetables annually, roughly one-third of reported production, revealing substantial opportunities but also structural limits due to spatial variation.

Pierre Chopin, Anton Parisi, Paola Clerino, Agnès Fargue‐Lelièvre, Carnel Megbleto, Lia van Wesenbeeck, Anna Kirstgen, Paris Pencharz, Charlotte Liborio-Cornet, Marta Sylla, Tomasz Kowalczyk, Gati András, Nadira Berbić, Iva Bedenko, Michele D'Ostuni, Penny Zafiraki, Odysseas Sekkas, Tina Katika, C. Kennard · Zenodo (CERN European Organization for Nuclear Research) · Europe

This presentation compiles insights, case studies, and strategic models from the "City Soils, City Souls: Urban Agriculture Contribution" workshop, an official New European Bauhaus satellite event. It merges findings from the Horizon Europe FOODCITYBOOST project and other EU initiatives to outline data-driven, community-led strategies for combating urban sprawl, revitalizing peri-urban land, and building circular food systems in European cities.

Angelica Mendoza Beltrán, Susana Toboso‐Chavero, Juan David Arosemena Polo, Adriana Lucia Romero Lestido, gara villalba · npj Urban Sustainability · Spain (Barcelona)

This study investigates the spatial and temporal effects of nutrient circularity strategies in peri-urban agriculture (peri-UA) using a regionalized life cycle assessment tool, focusing on the Metropolitan Area of Barcelona. It examines how nutrient recovery from municipal waste impacts climate change, eutrophication, resource depletion, and water consumption. The research finds that applying compost with current waste management infrastructure can reduce the carbon footprint of peri-UA areas by up to 85%.

Yun Gao, Nwakaego Onyenokporo, Manas; id_orcid 0000-0003-4791-8583 Murthy, Tamiris; id_orcid 0000-0002-4563-2429 Capellaro Ferreira · Huddersfield Research Portal (University of Huddersfield) · United Kingdom

This paper examines how integrated design supports the effective reuse of waste materials from a modular building factory through the design of a community garden pavilion. Using Whole Lifecycle Assessment, the carbon impacts of three scenarios were evaluated. Results showed that the scenario reusing waste materials (Case 3) achieved an 81% reduction in whole-life carbon emissions, totaling 3,044.99 kgCO₂e, compared to the baseline scenario using new materials (Case 1).

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.

Agnieszka Klucznik-Tӧrő · Economics and Environment · Europe

This research investigated whether vertical gardens can effectively reduce urban air pollution, using Cracow as an example. Field experimentation, biochemical and laboratory studies, statistical analysis, and quantitative techniques were applied using plant species such as fennel spike, lemon balm, thyme, chives, dill, and common ivy. The analysis proved that a significant level of phytoremediation of air pollutants can be achieved with vertical gardens.

Abdullah Ahmadi, Daniele Codato, Francesca Peroni, Massimo De Marchi · Urban Climate · Italy (Padua)

The Rooftops for Equity and Sustainability (RT4ES) model, a GIS-based multi-criteria decision analysis, was applied to Padua, Italy, to map suitable urban rooftops for green roofs and photovoltaic systems. The model identified 11.67 km² of suitable rooftops across 29,493 buildings, with rooftop greening offering 10.94 km² of additional vegetated surfaces and rooftop PVs potentially generating 302% of municipal household electricity. RT4ES prioritizes underserved neighborhoods by integrating social and environmental vulnerability.

Lorenzo Federico, Valeria Tatangelo, Francesca Pittino, Claudia Russo, Emanuele Vegini, Sandra Citterio, Andrea Franzetti, Sara Villa · Urban Ecosystems · Europe

This pilot study investigated the use of behavioral bioassays as screening indicators for invertebrate and bacterial biodiversity in three urban soils in Europe. While model organisms' behavioral responses consistently aligned with reductions in invertebrate biodiversity, these changes did not emerge from microbial analysis. The findings support behavioral bioassays combined with faunal diversity assessments as a first-tier screening tool for urban soil health, but suggest further investigation is needed for links with microbial diversity.

Nicolás Carrasco-Astudillo, Juan José Medina-Musellas, Kàtia Gaspar, Marta Gangolells, Miquel Casals · Building and Environment · Spain (Catalonia)

This paper evaluates rooftop agrivoltaic systems integrating urban agriculture, photovoltaic generation, and rainwater collection for building resilience and water-energy-food synergies. Tested via EnergyPlus simulations in a reference residential building across nine climate zones in Catalonia, Spain, the strategy showed climate-dependent benefits. The most consistent performance was in the Csa climate (Barcelona), demonstrating robust reductions in energy demand, emissions, and discomfort hours under current and future climate scenarios.

Ayhan Horuz, Güney Akınoğlu · · Turkey

A Turkish book chapter arguing that agriculture-derived air pollution, compounded by growing industrial and urban pollutant loads, is threatening food production, product quality, and food security by directly and indirectly impairing plant growth and development. It notes that population growth, energy production, transportation, waste management, and biomass burning have substantially increased atmospheric organic and inorganic pollutants, pushing air quality beyond acceptable limits in many regions. The first part evaluates the effects on agroecosystems of tropospheric (ground-level) ozone, PM2.5 and PM10, nitrogen oxides (NOx), sulfur dioxide (SO2), agricultural ammonia (NH3), and volatile organic compounds (VOCs), detailing how tropospheric ozone suppresses photosynthesis causing yield losses in staple crops such as wheat and soybean, and how particulate matter directly and indirectly affects soil and plant health, alongside the effects of acid rain and nitrogen deposition on soil fertility, water quality, and ecosystem balance, assessed against the four pillars of food security—availability, access, utilization, and stability. The second part discusses integrated policy approaches, industrial emission control technologies, and low-emission transport systems at the macro level, alongside agricultural strategies such as precision farming, improved fertilizer management, and innovative production techniques, and the role of green infrastructure in urban planning.

Paul Miner · Journal of urban regeneration and renewal · United Kingdom

This paper evaluates the evolving role of Green Belt policy in England, arguing that both the designation and the land it protects are increasingly critical to addressing environmental, climate and public health challenges. It defines the extent and characteristics of Green Belt and other "countryside around towns" land, showing that these areas prevent urban sprawl, support nature recovery, provide public access to green space and sustain cultural landscapes, while highlighting mounting pressures including housing demand, weakened planning controls, losses in farming capacity and newly introduced "grey belt" policy reforms, and recommending measures such as reinstating strategic planning through Spatial Development Strategies, adopting a brownfield-first approach, prioritising environmental land management, and considering new Green Belt designations or expanded National Landscape protections.

V. Costanzo, M. Detommaso, G. Evola, F. Nocera, M. Mistretta, S. Longo · Energy and Buildings · Italy

A study introduces and validates a novel Deep Water Culture hydroponic roof system as a building-integrated solution for enhancing indoor thermal conditions and energy efficiency in Mediterranean climates. Unlike conventional green roofs, the system removes the soil layer and uses a water-based nutrient solution that simultaneously supports plant growth and acts as a thermal energy buffer; a full-scale prototype was experimentally tested on an existing office building in Catania, Italy, and transient thermal modelling with TRNSYS then simulated different roof configurations using the experimental data. Results show the hydroponic roof reduces indoor peak temperatures by up to 2.8°C in summer, increases them by 2.4°C in winter, and shifts heat flux peaks by up to 16 hours, with annual simulations indicating energy savings of 47% for space cooling and 51% for space heating.

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.

· Wikipedia (German) · Germany

This article on green roofs in Germany explains that some major cities subsidize up to 50% of installation costs, and reduced stormwater fees (averaging €0.46/m2/year, up to €1.12/m2/year in Cologne) are also used to encourage adoption. Green roofs can be mandated in municipal development plans and used as ecological compensation measures, with about 8 million m2 newly greened annually nationwide, over 80% of it extensive systems.

· Wikipedia · Europe

Le Corbusier's 'Five Points of a New Architecture,' presented in 1927 and revised in 1929, comprise pilotis, the roof garden, the free plan, the horizontal (ribbon) window, and the free façade. The roof garden was framed as opening the roof to 'systematic domestic use,' and was realized in buildings such as Villa Savoye (completed 1931).

Stichting DakAkker · Stichting DakAkker (official) · Netherlands

The official site of DakAkker, a rooftop farm on top of the Schieblock building in Rotterdam. It describes itself as a 1,000-square-meter rooftop farm growing vegetables, edible flowers, and fruit and keeping bees, calling itself the largest open-air rooftop farm in the Netherlands and one of the largest in Europe. It is presented as an initiative of ZUS (Zones Urbaines Sensibles) and the Rotterdam Environmental Centre together with Optigrün Benelux and binder daktuinen, framed as part of Rotterdam's first city initiative 'de Luchtsingel.' The roof also hosts 'Slimdak,' a test site for smart rainwater management. 'Dakennie,' its environmental education program for Rotterdam primary schools, is financially supported by Watersensitive Rotterdam, the City of Rotterdam's nature and environmental education division, and the Hoogheemraadschap Schieland en de Krimpenerwaard water authority. The page itself does not state an opening year, which could not be confirmed here.

· Wikipedia · Netherlands

A floating dairy farm in the harbour of Rotterdam, described by its founders Peter and Minke van Wingerden as the world's first. It opened on May 13, 2019 with 32 cows, with plans to grow to 40. It is designed to use residual city products such as park grass and food waste to feed the animals, processes raw dairy into milk and yoghurt onsite for distribution in the city, and returns cow manure as fertilizer for public spaces. All power comes from solar panels, rainwater is collected on the roof, and milking, manure cleanup, and feeding are largely automated.

Plantlife · Plantlife · United Kingdom

An overview of Plantlife's 'No Mow May' campaign, urging people in the UK to stop mowing their lawns during May to let wildflowers grow and support bees and butterflies. The page states that approximately 97% of the UK's flower-rich meadows have been lost since the 1930s, and notes there are around 23 million gardens in the UK, meaning even small patches can add up. It encourages extending the practice beyond May into a year-round 'No Mow Movement' of managing lawns with mixed grass lengths for nature.

Chris Blythe, Silvio Caputo, Michael Hardman, Paul Milbourne, Mina Samangooei, Victoria Schoen · · United Kingdom

This chapter provides a narrative review of how urban food growing in the UK responded to past crises and during the COVID-19 pandemic. It discusses the positive impacts of urban food growing on individual, household, and community resilience, well-being, environment, and local food systems during the pandemic. The chapter suggests that further recognition and support for urban food growing would improve its ability to respond to future crises.

Sandra Mallet, Baptiste Colin, Thomas Zanetti, Marc G. Dumont, Annette, Groux · HAL (Le Centre pour la Communication Scientifique Directe) · France (Bordeaux)

The TransUrba project investigates how different temporalities of action in urban space can be articulated by studying temporary urbanism initiatives. Through an analysis of three areas in France (Bordeaux, Lyon, and Lille metropolitan area), the project aims to understand how temporary urbanism is implemented, its innovative features, its impact on urban space, and how local public action can strengthen transitional urbanism.

Nihat Karakuş · Journal of Agricultural Production · Turkey (Antalya)

This study quantitatively assessed the cooling effect of an urban agricultural area (a citrus orchard) in Antalya, Turkey, using Land Surface Temperature (LST) data from Landsat 8 OLI/TIRS satellite imagery on July 30, 2024. The mean surface temperature of the urban agricultural zone was 42.69 ± 1.26 °C, which was, on average, 1.46 °C colder than adjacent urban districts within a 600 m buffer zone. The cooling impact extended effectively up to 270 meters from its boundary, with effects ranging from 0.06 °C to 1.65 °C, diminishing statistically significantly with distance (p < 0.001; R² = 0.93).

Madeleine Pries, Walther Zeug, Daniela Thrän · Cleaner and Responsible Consumption · Germany (Leipzig)

A Holistic and Integrated Life Cycle Sustainability Assessment (HILCSA) was applied to a Community Supported Agriculture (CSA) initiative in Leipzig, Germany, supplying seven fruits and vegetables to schools, comparing it to a conventional food market. Based on 82 indicators, the CSA showed 63% fewer sustainability risks and a positive contribution to SDGs, with replacing conventional supply for 200 pupils avoiding 1 ton of CO2 equivalents annually. However, the CSA had significantly lower yields than conventional production, despite similar water, land, and energy uses per hectare, and spent mushroom substrate caused the highest upstream impacts.

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.

Marco Focacci, Isabella De Meo, Alessandro Paletto, Fabio Salbitano · Agroforestry Systems · Italy

A study analyzed urban plans, national laws, and regional legislation in Italy, along with interviews with decision-makers, to examine the occurrence of Urban and Peri-urban Agroforestry (UPAF). Findings showed that 4 out of 140 Italian cities intentionally included agroforestry in voluntary green plans, and 12 cities had incidental UPAF elements in compulsory documents. This indicates agroforestry is present but not widely incorporated, with grass-root organizations and knowledge hubs being crucial for its promotion.