Research & reports

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.

R. E. Molenaar, Marcel Pleijte · · Netherlands

A Wageningen University Science Shop report examines measures to improve water management for the "duinlandjes", centuries-old allotment gardens in the dunes near Egmond aan Zee, Netherlands, that form part of the Zeesdorpenlandschap cultural heritage. Commissioned by the Duinlandjesvereniging de Noord association, it investigated sustainable solutions from sociocultural, hydrological and ecological perspectives. The duinlandjes are currently experiencing flooding that makes cultivation very challenging. A stakeholder analysis found that while collaboration between the association and drinking water company PWN has advanced, interactions among stakeholders remain fragmented, and it calls for the province of Noord-Holland to take an active coordinating role. The hydrological analysis identifies winter precipitation surplus as the main driver of rising groundwater, projecting that climate change will bring wetter winters and drier summers with greater groundwater fluctuation, though long-term groundwater trends remain uncertain while winter/spring water excess will probably continue. The ecological risk assessment highlights the vulnerability of surrounding dune habitats, noting that draining and diverting excess rainwater can cause habitat degradation and increased drought stress.

Klara Muranyi, Ina Säumel, Donoso José, Edi Emilov Ivanov, Elena Heim, Sophia Kipp, Stephanie Ligan, Marisa Pettit, Thomas Wachtel, Anneli S. Karlsson, Bettina Schneider, Stephanie Degenhardt, Hilde Marie Herrebrøden, Inken Schmütz, Tina Hilbert, Sergio Torres Gimenez, Blanka Suler, Mollenhauer Mollenhauer, Vic Borrill, Ruth Smart, Antonia Torres, Martin Regelsberger, Latifa Bousselmı, Lamia Bouziri, Kai Gildhorn, Erwin Nolde, Katrin Bohn, Primož Banovec, Atanasova Natasa, Max Manderscheid, Milena Klimek, Lucia Alexandra Popartan, Kristin Reichborn‐Kjennerud, Sarah Noémie Plassnig, Joaquim Comas, Sebastian Eiter, Wendy Fjellstad, Nevelina Pachova, Aeden Ratcliffe, Zhifang Wang, Paula Firmbach, Hanna Burckhardt, Laura Martinez, Helen Gallis, Rutger Henneman, Nienke Bouwhuis, Caroline Zeevat, Paul de Graaf, Noel Arozarena Daza · Zenodo (CERN European Organization for Nuclear Research) · Europe

Deliverable D7.6, "Final ECS Curricula, Training Modules and Materials," published on Zenodo, is part of the EU Horizon 2020-funded EdiCitNet project (Edible Cities Network, 2018-2024). It compiles the curriculum for a free Massive Open Online Course, "Making Cities Edible: Cultivating Sustainable Urban Environment," covering Edible City Solutions (ECS) — an approach going beyond vertical gardens, rooftop farms, community kitchens and urban aquaponics to include biodiversity conservation, waste reduction, water recycling, social engagement and co-creation. The underlying ECS Knowledge Base was built through a co-creation process involving communities of knowledge and practice, and course content is organized into four fields: I) ECS Governance, II) Economic value of ECS, III) ECS as Ecological Systems, and IV) Socio-cultural impact of ECS. It targets initiatives, urban developers, small and medium-sized businesses and interested individuals, with the course led by a team of instructors with expertise in urban agriculture, sustainability and community development.

Katalin Horotán, Jana Táborská · Repository of the Academy's Library (Library of the Hungarian Academy of Sciences) · Europe

Against the background of children's gradually weakening connection to nature amid spreading urban lifestyles and digitalization, this paper presents the concept of "accessible nature," which places direct, local experience of nature at the center of environmental education. The described program, "The World of Our Garden" (Kertünk világa), uses urban gardens as learning environments and offers modular activities grounded in experiential and inquiry-based learning. Through observation and hands-on activities, students gain insight into natural processes while developing scientific thinking, an emotional connection to nature, and cooperative skills. Using examples, the paper shows how a schoolyard or community garden in an urban setting can become a complex, motivating learning space for sustainability education.

Julija Bakunowitsch · Urban Planning · Germany

This qualitative study examines a publicly funded urban gardening project in Dortmund, Germany, implemented as a labor-market activation measure on temporarily available land targeting employable welfare recipients. Drawing on interviews, participant observation, and document analysis, it combines the concept of "food justice" with valuation studies to analyze how labor, land, and exchange are valued in everyday practice. The findings reveal tensions between empowerment and dependency, care and control, and social recognition and material precarity: while participants experienced gardening as meaningful work and a source of social participation and belonging, these valuations remained bounded by welfare regulations, temporary land tenure, and charity-based food distribution. The study concludes that such temporary urban gardening projects function as sites of plural, negotiated valuation where justice is enacted only provisionally, through everyday practice, within the limits of welfare governance.

Guilherme Raj, Flor Avelino, Marie-Claire Bribois · Cambridge University Press eBooks · Europe

This chapter argues that power dynamics have received limited attention in sustainability-transitions research despite their centrality to lasting societal change, and introduces two frameworks -- "power to, over, and with" and "three relations of power" -- to analyze how power relations shift over time and are constituted. Applying these frameworks to a case study of community-supported agriculture in Portugal, the analysis shows how individual and collective agency, human and non-human interactions, and historical structures of social relationships shape opportunities and barriers for transitions. It concludes that more power-aware research incorporating non-Western and Indigenous epistemologies is needed.

Nicholas Balfour, Johnstone Caitlyn, Emma Bush · Zenodo (CERN European Organization for Nuclear Research) · United Kingdom

A 2025 survey of 31 green spaces in central Edinburgh, UK, including allotments, public gardens, cemeteries and roof gardens, assessed pollinator diversity and resource availability. The pollinator community was a generalist assemblage dominated by bumble bees (45%) and honey bees (26%), while butterflies, moths and beetles were notably scarce. Semi-natural areas, allotments and cemeteries sustained the highest pollinator diversity, linked to native vegetation and rich floral resources. Two-thirds of the plant species recorded were non-native horticultural varieties, yet 87% of recorded plants were visited by pollinators, and the three plant species attracting the widest range of pollinator taxa were all indigenous.

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.

HM Revenue & Customs (GOV.UK) · GOV.UK / HM Revenue & Customs (HMRC) · United Kingdom

The UK's Agricultural Relief lets qualifying agricultural property — farmland, pasture, stud farms, farmhouses and cottages among others — pass free, or partly free, of Inheritance Tax. Owner-occupied land (or occupied by a spouse/civil partner) must be held for 2 years, land let to others for 7 years, to qualify. Relief is 100% where the owner farmed the land themselves or it is let on a tenancy starting after 1 September 1995, and 50% in other qualifying cases. For deaths on or after 6 April 2026, the combined 100% Agricultural Relief and Business Relief allowed against an estate is capped at £2.5 million, with any excess receiving 50% relief instead.

· Wikipedia (English) · Spain

According to English Wikipedia, the Water Tribunal of the Plain of Valencia was founded during the reigns of the Caliphs Abd-ar-Rahman III and Al-Hakam II, in 960 CE, as an institution of justice to settle disputes over irrigation water. It is made up of one representative (síndic) from each of nine Irrigation Communities, one of whom serves a two-year term as president. It meets every Thursday at Casa Vestidor on Plaça de la Mare de Déu in Valencia, and in 2009 was inscribed by UNESCO as intangible cultural heritage alongside the Council of Wise Men of the plain of Murcia.

· Wikipedia (español) · Spain

A Wikipedia article on the Huerta de Valencia, the historic agricultural belt surrounding the city of Valencia. Origins trace to Roman settlement, but the irrigation infrastructure that shaped the current landscape was developed during the Al-Andalus (Islamic) period. Nine major irrigation canals (acequias), including Quart and Mestalla, are governed by the Tribunal de las Aguas de Valencia, inscribed on UNESCO's Intangible Cultural Heritage list.

· Wikipedia (English) · Spain

An English-language Wikipedia article on the Horta of Valencia, the historic agricultural area surrounding metropolitan Valencia, covering 631.9 km2 with a 2019 population of 1,567,118. Its traditional Arab-era irrigation system was designated a FAO Globally Important Agricultural Heritage System (GIAHS) in 2019 as the 'Historical Waterscape of l'Horta de Valencia.'

Ajuntament de Barcelona · Ajuntament de Barcelona / Institut Municipal de Parcs i Jardins · Spain

The official page of Barcelona's municipal allotment network, offering 15 allotment sites across the city's ten districts, with plots of 20-40 m2 leased to residents aged 65+ and non-profit organizations. The program formally launched in 1997 with the Can Mestres allotments, though the very first allotment, Hort de l'Avi in Gràcia, dates to 1986 following a resident petition. Plots for individuals are allocated by lottery and for organizations by competition, with stated goals of environmental education and intergenerational coexistence.

· Wikipedia (italiano) · Italy

An Italian Wikipedia article on Parco Agricolo Sud Milano, established on 23 April 1990 under Lombardy regional law (LR 24), covering 46,300 hectares across roughly 60 municipalities. More than 1,400 farms operate within the park, with cereals accounting for 43% of cultivation, rice 22%, and forage 16%. Forty-one traditional irrigated meadows (marcite) are protected within the park, alongside native mammals, birds, reptiles, amphibians and fish, plus reported invasive species such as nutria.

· Wikipedia (italiano) · Italy

An Italian Wikipedia article on the cascine (traditional farmsteads) of Milan, of which about a hundred survive today, 59 of them municipally owned. Eighteen are derelict, while the rest are used as libraries, recreation centres, facilities for the elderly and disabled, or housing; thirteen remain active farms engaged in rice cultivation, dairy farming, or horse breeding. The oldest, Cascina Chiesa Rossa, dates to the 10th century, with other major cascine built between the 11th and 15th centuries.

· Viquipèdia (Catalan Wikipedia) · Spain

The Parc Agrari del Baix Llobregat is a protected agricultural area (about 3,473 ha, with 2,938 ha designated as farmland) in the Llobregat river delta within the Barcelona metropolitan region, managed by a consortium established in 1998. Vegetables account for 63% of crops, with fruit trees making up most of the rest. Spanning 14 municipalities, it functions as an institutional framework preserving agricultural landscape and wetland ecosystems amid urban expansion.

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).

· Wikipedia · United Kingdom

Kensington Roof Gardens is a roughly 6,000 sq m garden atop the former Derry & Toms department store building, designed and built between 1936 and 1938 by landscape architect Ralph Hancock, comprising three themed gardens: a Spanish garden, a Tudor-style garden, and an English woodland garden with a stream and pond. The trees received a tree preservation order in 1976, the garden was Grade II listed in 1998, but public access ended in 2018; after a 2021 acquisition, it reopened in 2024 as a private members' club.

· Wikipedia · United Kingdom

According to the English Wikipedia article 'Manor Garden Allotments', the Manor Garden Allotments in London was a 4.5-acre (18,000 m2), 80-plot allotment site established in 1924 by Major Arthur Villiers. It was cleared in October 2007 to make way for landscaping of the London 2012 Olympic Park, and tenants were moved to a temporary site two kilometres away. Restoration on the original site and a 2.1-hectare provision of replacement plots were promised, but the successor Pudding Mill Lane allotments did not open until roughly four years after the Games ended.

· Wikipedia (ドイツ語) · Germany

This German Wikipedia article on the Edible City movement traces its origin to 2008 in Todmorden, England, where Pamela Warhurst and Mary Clear founded 'Incredible Edible'; by 2017 the UK Incredible Edible Network linked more than 100 groups. In Germany, the association 'Essbare Stadt' was founded in Kassel in May 2009 based on permaculture principles, while Andernach's municipal project began in 2009 and gained nationwide attention after being presented at Berlin's International Green Week in 2014. By 2017 over 140 such initiatives calling themselves 'edible' were found online. Since 2008, Toronto has promoted a comprehensive municipal program including community gardens, education, and food-waste initiatives.

· Wikipedia · United Kingdom

This Wikipedia article covers Incredible Edible, an urban gardening movement started in 2007 in Todmorden, UK by Pamela Warhurst, Mary Clear and others, run on a 'three spinning plates' model of community (public-space growing anyone can pick from), business (supporting local food firms), and learning (food education). As of 2018 there were 120 official UK groups and over 700 worldwide; UK groups reported a 37% year-on-year rise in produce, 9,763 sqm of growing land, 4,861 participants, and 207 events. The project received a £500,000 grant from the Big Lottery Fund.

· 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.