Research & reports

Abigail Benson, NICHOLAS O EHISIENMHEN, EUNICE T ADEWALE, R ANIMASAHUN-OLADIMEJI, TOBA R ARIBILOLA, RAZAQ A AFIZ, Augustine Okeke, Oliver P. John, Idris Ahmad Isa, BADRAT O IMRAN, KELVIN D DIRISU, OMOTOYE O OMISORE · Greener Journal of Agricultural Sciences · Nigeria (Ondo State)

This study assessed the impact of urbanization on agricultural land in Akure South Local Government Area, Ondo State, Nigeria, using populated figures and land use data from satellite images for 2002, 2012, and 2022. GIS analysis revealed an increase in settlement and a decrease in agricultural land from 2002 to 2022. Urbanization significantly decreased agricultural land, farming activities, and farm size, driven by increasing settlement and built-up areas.

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%).

Arun Kafle, James Hopeward, Baden Myers · Sustainability · Global

An integrated modelling framework using proxy measures for economic benefit (net margin), social benefit (full-time farmer employment equivalent per consumer) and environmental benefit (CO2 emission reduction) was applied to two contrasting development settings, Adelaide, Australia, and the Kathmandu Valley, Nepal, to examine the characteristics of urban agriculture (UA). Using two-stage optimisation across three mechanisation levels (non-mechanised, garden tiller, garden cultivator), two purposes (gardening or commercial), two crop-value categories and two market mechanisms, the model found that no single UA form maximises economic, environmental and social (employment) objectives simultaneously: commercial UA, in which both land and labour are costed, was favoured for maximising profit or reducing CO2 emissions, while gardening-form UA was favoured for maximising employment participation. In Adelaide the model favoured commercial UA for best-case profit and carbon emissions but gardening UA for employment maximisation, while in the Kathmandu Valley the model selected gardening UA under the given assumptions.

Veronica Sebald, Julia M. Schmack, Monika Egerer · Renewable Agriculture and Food Systems · Germany

This study surveyed the occurrence of poisonous plant species in 30 urban community gardens across two German cities, Berlin and Munich, and examined concerns around poisonous and highly poisonous plants in urban garden settings. It found that plants producing substances toxic to humans occur in these gardens while also potentially holding ecosystem-functioning and biodiversity-conservation value, creating a trade-off with the ecosystem service of human health promotion, and concludes that poisonous plants should be carefully monitored and managed—depending on garden participants and the goals of the garden organization—to mitigate health risks while still supporting biodiversity conservation.

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%.

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.

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.

Imen Bendjemila, Salah Chaouche · DOAJ (DOAJ: Directory of Open Access Journals) · Algeria

Urban sprawl in N'Gaous, Algeria, expanded its land area by over ten times (from 33.7 to 379.7 hectares) and its population by over six times (from 4,887 to 33,515 persons) over 60 years. This rapid growth creates significant issues, particularly for peri-urban orchards, which are the primary economic activity. The study used an analytical approach with Geographic Information Systems to assess the agronomic potential of soils and quantify agricultural land consumed by construction, aiming to achieve an optimal agri-urban balance rather than merely avoiding urban expansion.

Joan Casanelles‐Abella, Simone Fontana, Bertrand Fournier, David Frey, Marco Moretti · Ecological Applications · Switzerland (Zurich)

This study in 23 urban gardens in Zurich, Switzerland, examined feeding niche partitioning between wild bees and honeybees. Researchers found that feeding niche partitioning increased with wild bee species richness and in sites with lower landscape-scale resource availability, which also had lower honeybee abundances. However, beekeeping intensity at local and landscape scales did not directly influence community feeding niche partitioning or wild bee species richness, suggesting direct competition for resources was not a main driver for the wild bee community.

Ionat; id_orcid 0000-0001-9080-2282 Zurr, Oron; id_orcid 0000-0002-2893-5364 Catts · UWA Profiles and Research Repository (University of Western Australia) · Australia

The "Sunlight, Soil & Shit (De)Cycle" project, presented by SymbioticA in February 2022, is a performative experiment exploring agricultural technology (AgTech) and its aim to remove natural elements like sunlight, soil, and organic waste from food production. This project considers whether the precursor to sustainable food systems will be the creation of a metabolic rift, where the means of production grow ever distant from nature. It highlights a critical environmental tradeoff by questioning the separation of humans from nature in technological farming.

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.

Muhammad Sarjan, M. Taufik Fauzi, Ruth Stella P. Thei · Unram Journal of Community Service · Indonesia (Mataram City)

This action research in Mataram City during the COVID-19 pandemic introduced Integrated Pest Management (IPM) practices to urban farming groups. Group discussions revealed that while participants were interested in developing fresh vegetables and fruits and found benefits in meeting family food needs, most members were unfamiliar with environmentally friendly cultivation techniques, particularly IPM.

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.

Imen Bendjemila, Salah Chaouche · Prostor : znanstveni časopis za arhitekturu i urbanizam · Algeria

This study investigated urban growth and urbanization in N'Gaous, Algeria, over the last 60 years, using an analytical approach and Geographic Information Systems to assess the agronomic potential of soils. It found that N'Gaous experienced significant urban sprawl, with its land area expanding over ten times and population increasing more than six times, leading to serious issues for peri-urban orchards. The study quantified and monitored the agricultural potential consumed by construction, highlighting the negative impact of urban expansion on agricultural land.

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.

Kinanti Safitri, Oekan S. Abdoellah, Budhi Gunawan, Parikesit Parikesit, Yusep Suparman, Akhmad Mubarak, Margareth Pardede · The Qualitative Report · Indonesia (Bandung)

This mixed-method study, involving 107 export-scale urban farmers in the Bandung metropolitan area, Indonesia, investigated their adaptation during the COVID-19 pandemic. Farmers prioritized commercial agriculture and adapted through market access, agricultural management, and financial resource strengthening. However, some adaptation methods were not environmentally friendly, as farmers increased reliance on synthetic inputs and used cold storage on open land, leading to intensive, non-environmentally friendly agricultural practices.

Lady L. S Gundim, Renata Priore Lima · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · Brazil (São Paulo)

This article investigates the benefits of vertical farms as a sustainable food production model in cities, using a literature review and a case study of Pink Farms in São Paulo/SP, Brazil. Results indicate benefits such as energy and land use optimization, but also highlight ecological, social, and landscape limitations.

Laís Caroline Marianno de Olivera, Gislaine Costa de Mendonça, Renata Cristina Araújo Costa, Regina Aparecida Leite de Camargo, Luís Filipe Sanches Fernandes, Fernando António Leal Pacheco, Teresa Cristina Tarlé Pissarra · Land Use Policy · Brazil

This study investigated the impacts of 35 years of urban expansion in Brazil's Administrative Region of Ribeirão Preto, linking it to agricultural land loss and environmental consequences. Using Landsat images and GIS, the research found rural area losses exceeding 350 km2, with equivalent production and economic losses of approximately 1.1 Mton/year and 230 MR$/year. Significant environmental impacts included the destruction of over 9100 km of natural watercourses, nearly 630 km2 of Permanent Preservation Areas, and the occupation of Guarani Aquifer recharge areas with impermeable surfaces, affecting approximately 7000 headwaters.

Anne-Louise Fritz, Ramia Jannoura, René Beuschel, Christoph Steiner, Andreas Buerkert, Rainer Georg Joergensen · Chemical and Biological Technologies in Agriculture · Africa

This 2-year study in semi-arid Ouagadougou and sub-humid Tamale, West Africa, measured the effects of biochar and N fertilization on soil microbial biomass carbon, fungal ergosterol, and functional diversity. Sole biochar addition did not affect soil chemical or biological properties, but biochar with N fertilization increased microbial respiratory response. N fertilization decreased soil pH by 1.1 units in both cities, and a pH of 4.7 led to reduced microbial biomass carbon and ergosterol contents in Tamale. An N fertilizer-induced decline in soil pH below 5 should be avoided, as it decreased microbial biomass carbon and microbial functional diversity.

Paulien C. H. van de Vlasakker, Karin Tonderski, Geneviève S. Metson · Frontiers in Sustainable Food Systems · Global

A review of empirical peer-reviewed studies (2000-2021) on nutrient losses to water from soil- and ground-based urban agriculture. Of 241 publications screened for a stated concern with nutrient losses to water, 20 were retained, but only seven had actually measured losses to water. Of four experimental studies, three measured leachate losses under different garden management practices; of 16 real-world studies, only four quantified losses to water as leachate, with measured average losses ranging from 0.005 to 6.5 kg/ha for phosphorus and 0.05 to 140 kg/ha for nitrogen. Thirteen of the 16 non-experimental studies provided input and harvested-crop data allowing nutrient balances to be calculated; despite wide value ranges, most studied gardens showed nutrient surpluses (inputs exceeding crop harvest) for nitrogen and phosphorus but not potassium, identified as a risk factor for losses to water, though large surpluses were not always linked to higher leachate losses. The review concludes that more field studies measuring actual losses to water, and documenting contextual factors, are needed to determine whether urban agriculture can contribute to a circular economy without causing nutrient-related water quality impairment.

Jaime Pizarro‐Araya, Fermín M. Alfaro, Francisco Gómez, Roberto Villablanca · Anthropocene Coasts · Chile

A 2022 study characterized the taxonomic richness and abundance of terrestrial arthropod fauna at the Aguada de La Chimba urban coastal wetland in the Antofagasta Region, Chile, using multiple survey methods. From a total of 1,874 specimens, it identified 109 terrestrial arthropod species, with Insecta the most represented taxon (85 species, 47 families, 15 orders); by origin, communities included 24% native, 22% naturalized, and a smaller proportion of endemic species. The study reports that urban coastal wetlands are fragile ecosystems subject to serious disturbance in structure, function, and diversity from advancing urban, agricultural, foraging, and drainage activities, including displacement of endemic species by invasive ones, and discusses the major threats to this wetland alongside the importance of public-private partnerships with the local community for biodiversity conservation.

Pu Xu, Shanwei Li, Xiaona Yang, Yufeng Li · Journal of Environmental and Public Health · China

Agricultural statistical data from Shanghai for 1998-2019 were analyzed using an Environmental Kuznets Curve and a VAR model to examine the relationship between urban agricultural nonpoint source pollution (UANSP) and rural residents' income growth. An inverted "N"-shaped curve linked plastic film application intensity to per capita disposable income, while fertilizer and pesticide application intensity showed a linear negative relationship with income. Nonpoint source pollution emissions declined as income rose, and while reducing this pollution supported short-term income gains for rural residents, it had a negative effect on their long-term income growth.

Thulani Dube, Saziso Sibanda, Phibion Chiwara · Cogent Social Sciences · Zimbabwe (Bulawayo)

This study investigated farmers' perceived effects of climate change on peri-urban agriculture in Bulawayo, Zimbabwe, and their adaptation methods. Using a sample of thirty peri-urban plots, findings revealed that farmers perceived significant climatic changes negatively impacting their farming activities, including reduced precipitation, increased atmospheric temperature, and diminishing borehole yields. Adaptation methods included repeated planting, watering plants at night, renting animal space in other farms with more water sources, and purchasing supplementary feed for livestock.

Carlos Tapia, Linda Randall, Shinan Wang, Luciane Aguiar Borges · Sustainable Cities and Society · Denmark (Aarhus)

This study presents a novel indicator-based evaluation framework for urban agriculture, tested in Fællesgartneriet Brabrand, a community garden in Aarhus, Denmark. The framework aims to capture the contribution of gardening practices to urban sustainability, acknowledging that urban agriculture may also have social and environmental externalities depending on prevalent farming practices.