Research & reports

Joimel S., Grard B., Chenu C., Auclerc A., Bernard M., Mondy S., Dewulf L., Lelièvre M., El Mekdad F., Vieublé Gonod L. · European Journal of Soil Science · France (Paris)

Study of 12 urban microfarm plots in the Paris region found high intra- and inter-site variability in soil biological properties, with microfarm soils hosting lower bacterial diversity than forests or cultivated soils. Both ground-level and rooftop microfarms were surveyed.

Manal Emhemed Mu Chalgham, Halil Semih Eryıldız · Al-Farooq Journal of Sciences · Turkey (Istanbul)

This case study focuses on Okan University's Tuzla Campus in Istanbul, which already has sustainable features. The research proposes ecological retrofitting measures like edible landscaping, rainwater harvesting, and waste management to improve environmental performance and create an interactive learning environment. Analysis revealed major weaknesses in underutilized green spaces, inefficient natural ventilation, and lacking water/waste management systems, which the proposed retrofits aim to address.

María Roo, Cecilia Herbón, Juan Pedro Martín‐Sanz, María Teresa Barral, Remigio Paradelo Núñez · Journal of Soils and Sediments · Spain (Santiago de Compostela)

This study analyzed the chemical extractability and bioaccessibility of five trace metals (Pb, Cu, Zn, Ni, Cr) in 55 urban soils from Santiago de Compostela, Spain, across various land uses. The availability of trace metals in these soils was found to be very low. Plant-available and bioaccessible Cu and Zn were higher in urban garden soils compared to other uses, supporting hypotheses that Cu, Pb, and Zn originate from anthropogenic pollution.

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).

Anna C. Catania, Carmen Trischitta · Design Studies · Italy

This paper examined the role of design as a catalyst in experiential food education through the Curortò project, a therapeutic garden established within the G. Di Cristina Children's Hospital. Employing a participatory action research methodology, the project involved hospitalized children, healthcare professionals, educators, and local community actors in a collaborative design process. Detailed observation, field diaries, and qualitative interviews provided evidence of significant improvements in children's understanding of seasonal food cycles, resource management, and circular economy principles, accompanied by reduced stress levels and increased operational autonomy.

Lucy C. Michaels, María Puig de la Bellacasa · Environmental Humanities · United Kingdom

This article explores how soil care practices in urban gardening contribute to a sense of ecological belonging, focusing on diverse communities of urban growers from uprooted and migrant backgrounds in a city of the British East Midlands. Based on interviews and fieldwork, it shows how material, affective, and ethical relations in soil care may offer a distinct opening to more-than-human relations of belonging to/with land. Growers repair and nourish soil, connect to pasts and futures of urban land, and navigate affective and ethical ambivalences, reconfiguring place, identity, and more-than-human community.

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.

Florio Furno M, Tramontini M, Gaggero E, Rigoletto M, Fabbri D, Malandrino M, Calza P, Varese GC, Spina F · Applied Microbiology and Biotechnology · Europe

Polycyclic aromatic hydrocarbons (PAHs) persist in soil and resist common recovery strategies, which matters for urban agriculture because such sites are highly exposed to varied pollution sources — and because that exposure shapes how urban growing is perceived. This study examined the fungi already present in polluted soil intended for urban agriculture, aiming to build an active microbial consortium able to transform the pollutants and lower site toxicity. The mycobiota was dominated by Ascomycota; among 28 isolated taxa across 16 genera, Aspergillus, Scedosporium, Trichoderma and Fusarium were the most abundant. Isolates differed markedly, between and within species, in their ability to grow in the presence of low- and high-molecular-weight PAHs, and some produced biosurfactants. Combining this with the ability to grow on carriers, six fungi were selected for in situ soil remediation, and biostimulation was compared with bioaugmentation using strains in co-culture. The best results came from a consortium that also showed high tolerance to high-molecular-weight PAHs. Chronic ecotoxicity testing showed no effect on Eisenia fetida except under biostimulation, which produced a 44 per cent decrease in toxicity. A mix of millet and canary seeds worked as an efficient fungal carrier.

· Wikipedia · United Kingdom

This Wikipedia article covers Robert Hart (1913-2000), a British horticulturist credited as the pioneer of temperate-climate forest gardening. He converted a 0.12-acre (500 sqm) orchard at his Shropshire home into a model forest garden structured in seven layers (canopy, low-tree, shrub, herbaceous, ground-cover, rhizosphere, and vertical/climber). The article also notes he followed a roughly 90% raw vegan diet, citing the Hippocratic maxim to 'let food be thy medicine.'

European Commission · European Commission (single-market-economy.ec.europa.eu) · Europe

This is the European Commission's official Critical Raw Materials (CRM) page. It confirms that both 'Phosphorus' and 'Phosphate Rock' appear as separate entries on the EU's 2023 fifth CRM list. The page illustrates supply-concentration risk with examples for other materials (China supplying 100% of heavy rare earth elements, Turkey 99% of boron, South Africa over 71% of platinum group metals), but does not itself state a specific EU import-dependency figure for phosphorus or phosphate rock.

· 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.

· Frontiers in Sustainable Food Systems · Spain (Barcelona)

A study analysing both the agronomic and the organisational dimensions of Barcelona's community gardens, examining empirically how citizen-led urban gardens are managed and run.

Wilkens J., Mombo S., Dumat C. · Urban Science · France (Toulouse)

Examines 11 years of collective urban gardens in the Toulouse region through the lens of global health—encompassing human well-being, soil health, and interspecies interactions—as a driver of agroecological transitions among gardeners.

Irigoyen I., López M., Orden L., Moral R., Nogués I., Bustamante M.Á. · Agronomy · Europe (urban agriculture focus)

June 2025 study examining how decentralized and community composting are emerging as novel scenarios favoring localized management and valorization of organic waste streams. Supports organic waste reduction at community level and nutrient cycling for urban agriculture fertilization, offering alternatives to centralized composting.

· Sustainability · Barcelona, Spain

A systematic review integrating circular economy principles with urban agriculture to build resilient, low-emission urban food systems, using metropolitan Barcelona as a case, discussing zero-waste strategies including redistribution of surplus food.

Trenkner M., Kiesel A., Bauerle A., Lewandowski I. · Biofuels, Bioproducts and Biorefining · Stuttgart, Germany

Analyses the technical potential of urban biorefinery concepts for recycling plant nutrients from waste streams and wastewater in a German metropolitan region to close the urban-rural nutrient loop.

Medina Veliu, Hugo López-Romano, Giuseppe Picca, Marco Panettieri, Eduardo Moreno‐Jiménez, Denis Courtier‐Murias, Liliane Jean‐Soro, Johnny Gaspéri, Laura L. de Sosa · Ecotoxicology and Environmental Safety · Spain (Madrid)

This study investigated the impact of biochar-amended composts on trace element and nutrient dynamics in rooftop farming systems by cultivating tomatoes, lettuce, and Swiss chard for three years on a Madrid rooftop. Six substrates derived from spent coffee grounds, coffee silverskin, and seaweeds, with and without biochar, were used. Results showed that biochar reduced plant uptake and leaching of trace elements, lowering arsenic uptake by up to 40% in seaweed-based composts. Biochar also improved nutrient retention, reducing phosphorus and nitrogen losses by 40% and 25% respectively.

Jasna Grabić, Milica Vranešević, Pavel Benka, Srđan Šeremešić, M. Meseldzija · Sustainability · Europe

In Vojvodina Province, northern Serbia — a rural region where 70% of the territory has been converted to arable land — researchers used QGIS to map areas suitable for implementing Nature-based Solutions (NbS), drawing on CORINE Land Cover, OpenStreetMap, data from the Institute for Nature Conservation of Vojvodina Province, and the EUNIS platform. The area suitable for NbS totaled 1,183,228 ha, or 55.74% of the province, with organic and regenerative agriculture projected to increase by up to 5%. Grazing was identified and mapped as a desirable grassland management option, potentially practicable on nearly 10% of the territory.

Veronika Hansen, Franziska Häfner, Bianca Messmer, Luca Bragazza, Carsten Tilbæk Petersen, Jakob Magid · Agriculture Ecosystems & Environment · Europe

Using a long-term field trial (the CRUCIAL experiment) running for more than 20 years in Denmark, this study compared the long-term effects of bio-based fertilizers (BBFs) — compost, sewage sludge, cattle slurry, and human urine — against conventional mineral NPK fertilizer on soil physical, chemical, and biological properties. Mineral NPK fertilizer supported crop productivity and improved certain soil properties but did not deliver the broader soil health benefits of organic amendments; compost and sewage sludge notably increased soil organic carbon, cation exchange capacity, porosity, water content at field capacity, and microbial activity while reducing bulk density and clay dispersibility. Human urine produced a nitrogen fertilizer effect on crop yield comparable to NPK, but showed a higher sodium adsorption ratio than NPK and a negative trend in bulk density (though values stayed below critical thresholds), indicating a need for complementary organic matter input, and carbon-rich bio-based fertilizers reduced crop production per unit of nitrogen applied.

Christos Ioannides, Alexandra Tsatsou, Daniel Mamais, Simos Malamis, Georgios Tsimiklis, Dimitra Tsiakou, Z. Tsiropoulos, Mariarina Michailidou, Apostolos Tzourtziotis, Christina Karaberi, Orestis Raptis, Constantinos Noutsopoulos · Urban Water Journal · Europe

This study presents the design, implementation, and evaluation of a city-wide pilot of circular urban agriculture across 31 locations in Trikala, Greece. The pilots included rainwater harvesting, precision irrigation, composting, and an online monitoring platform. Assessed through a mixed-methods approach using 20 environmental, economic, and social indicators, the system showed stable technical performance and effectiveness in reducing resource consumption.

ADEME · ADEME Infos · France

One year after France's January 2024 mandate for source-separated food waste, ADEME reports that about 50% of residents (32.1 million people) now have access to municipal sorting services, 56% sort their food waste, and 9 million tonnes of biowaste per year have been diverted from incineration and landfill, backed by €100 million in green-fund investment since 2023.

Anne Lenormand · Banque des Territoires (Localtis) · France

Reporting that France's source-separation infrastructure for biowaste has tripled in three years since the January 2024 legal mandate, giving 32.1 million French residents (about 50%) access to sorting solutions (municipal collection, individual and shared composting). The rollout had a difficult start but is now accelerating, with 20 million more residents expected to gain access.

· PhysOrg (Research Report) · Multi-regional (France, Germany, Poland, UK, USA)

International citizen science study recruiting farmers and gardeners at urban agriculture sites in France, Germany, Poland, UK, and USA. Participants recorded daily diary entries of inputs and harvests. Found that urban farms may have higher carbon footprints due to intensive inputs, suggesting need for optimization of composting and organic waste utilization to reduce environmental impact.

Juan David Arosemena Polo, Susana Toboso‐Chavero, Biraj Adhikari, Gara Villalba · Waste Management · Spain (Barcelona)

This research determined the potential of organic municipal solid waste (OMSW) compost to supply nitrogen-phosphorus-potassium (NPK) demand for urban agriculture (UA) and its environmental benefits in the Metropolitan Area of Barcelona, Spain. Using spatial material flow analysis and life cycle assessment, it was found that the current waste management system could substitute 8% of total NPK demand with compost, reduce impacts by up to 39%, and yield 130% savings in global warming. A 2025 scenario could substitute 21% of NPK demand and reduce environmental impacts by up to 1,049%.