Research & reports

Julian Cribb · Cambridge University Press eBooks · Global

This paper points out that none of the world's megacities can feed themselves, and food chain risks pose an imminent threat of starvation. It presents concepts such as climate-proof food supplies, novel urban food production systems, the importance of urban permaculture, rewilding, and developing wise consumers as solutions to urban food risk. However, it does not explicitly state that these solutions fully resolve the issue of urban food self-sufficiency.

Neal Chalofsky · Advances in Developing Human Resources · Global

This paper reflects on the 35-year growth experience of the TPSS Food Cooperative, examining challenges faced by social entrepreneurship. It notes that individuals with vision often lack social movement learning (SML) and human resource development/organization development (HRD/OD) skills to grow and direct organizations, leading to their demise or a shift towards business over social aspects. The paper argues that lessons from the 1970s food cooperative movement can benefit contemporary social entrepreneurships.

Lucy Rose Wright, Ross Fraser Young · Manchester University Press eBooks · Global

This chapter introduces the concept of political gardening, contextualizing its rise within neoliberal processes and academic interest in urban gardening. It conflates political gardening with injustice, drawing on Rawls' theory of social justice. The chapter uses case study examples to define political gardening as a six-stage iterative process that participants undergo to address injustices and become engaged, democratized citizens.

A. Hegazy · Scientific Journal of Flowers and Ornamental Plants /Scientific Journal of Flowers and Ornamental Plants · Egypt

This landscaping study, conducted from 2017-2018, investigated eight school gardens in Mansoura City and Talkha District, Dakahlia Governorate, Egypt. The study revealed that most school gardens contained toxic plants like weeds and cacti, and that utilized areas were not correctly used with poor maintenance. Roof gardens and improved irrigation systems were suggested.

Baby Shaharoona, Said Al‐Ismaily, Ahmed Al‐Mayahi, Nadhira Al-Harrasi, Ruqaiya Al-Kindi, Abdullah Al-Sulaimi, Hamad Al-Busaidi, Mohammed Al‐Abri · Heliyon · Global

A study in A'Seeb city, Oman, combined a sociological questionnaire survey of residents' perceptions with sampling of pathogenic bacteria, water-soluble metals, basic cations, salinity and texture in soil and groundwater near urban gardens and municipal waste disposal sites. Most surveyed residents were not paying attention to the negative consequences of their activities on soil and the environment. Heavy metal concentrations were significant at some contaminated sites though still below international standards, while fecal contaminants were reported in some garden, waste-site and groundwater samples, identifying human pathogens in risk group 2 including Klebsiella pneumoniae, Shigella spp. and E. coli.

Ioannis Manikas, George Malindretos, Konstadinos Abeliotis · Journal of International Food & Agribusiness Marketing · Global

An essay that states urban food production is exposed to high levels of urban-generated contaminants, and argues that urban floriculture - an intensive form of agriculture with income per unit area far higher than other agricultural branches - can offer a more sustainable and socially acceptable alternative to urban food production. It states floriculture may also reduce the carbon footprint of cut-flower transport and provide higher-quality seasonal product, and examines urban floriculture as an approach for mitigating the negative impacts of global floriculture supply chains.

Lucy Rose Wright, Ross Fraser Young · Manchester University Press eBooks · Global

A chapter introducing the concept of political gardening. It begins by situating the re-evaluation of "everyday space" within neoliberal processes of privatization, devolution and entrepreneurialism, then connects the rise of academic interest in urban gardening with the movement's political dimension. Drawing on Rawls' theory of social justice, it conflates political gardening with injustice, uses case studies to unpack that process of addressing injustice across six iterative stages, and arrives at a definition of political gardening as both a term and a process through which participants become "democratized" citizens.

Asnath Alberto Malekela · · Tanzania

In Dar es Salaam, Tanzania, a study of climate change impacts on urban and peri-urban agriculture (UPA) drew on secondary literature plus primary data from structured and in-depth interviews, observations, and focus group discussions with 201 UPA practitioners. 84% of respondents engaged in UPA for food and income, and UPA made a positive contribution to food security. However, UPA was found to be severely affected by climate change: effects included drying of crops (41%), crop pests and diseases (28%), decreased crop yields (13%), loss of soil fertility (8%), animal diseases (43%), drying of pasture lands (41%), and livestock deaths (16%). The study states plainly that urban and peri-urban agriculture in Dar es Salaam is severely affected by climate change, and recommends adopting farming systems such as vertical farming that use limited water resources.

Michael Martin, Elvira Molin · Sustainability · Sweden

This study assessed the environmental impacts of urban vertical hydroponic farming through a life-cycle perspective, applied to a case-study vertical hydroponic farm in Stockholm, Sweden, comparing current performance with potential improvement scenarios. Results showed that growing medium, pots, electricity demand, and transportation of raw materials and product deliveries were the important contributors to environmental impact in this system. Replacing plastic pots with paper pots was found capable of producing large reductions in GHG emissions, acidification impacts, and abiotic resource depletion, and replacing conventional gardening soil with coir as the growing medium also led to large impact reductions. However, the study states that further reducing the system's impacts will require more resource-efficient steps specifically to address impacts from electricity demand, an issue not resolved by the pot and growing-medium substitutions, and identifies potential for more symbiotic exchanges using urban wastes and by-products.

Abdallah Zacharia, Wajihu Ahmada, Anne H. Outwater, Billy Ngasala, Rob Van Deun · The Scientific World JOURNAL · Tanzania

This cross-sectional study, conducted from February to August 2018, evaluated three waste stabilization ponds (WSPs) in the Morogoro, Mwanza and Iringa regions of Tanzania, where treated effluent is used for urban agricultural activities despite the disease-transmission risks posed by untreated or partially treated wastewater. Using APHA physicochemical methods, the modified Bailenger method and Ziehl-Neelsen staining for parasites, and membrane filtration for fecal coliforms (FC), analyzed with SPSS version 20, the study found helminth egg removal ranging from 80.8% to 100% and protozoan (oo)cyst removal from 98.8% to 99.9%, with the Mwanza WSP showing the highest FC reduction (3.8 log units per 100 mL). Both parasites and FCs in the effluents of the assessed WSPs were found at concentrations exceeding World Health Organization and Tanzania Bureau of Standards limits, except for helminths in the Morogoro WSP and FCs in the Mwanza WSP. FC counts correlated significantly with protozoa (p<0.01) and predicted protozoa occurrence well (p=0.011), with correlations also found among physicochemical parameters, parasites and FC bacteria. The study attributes the systems' inadequate performance to a lack of regular maintenance and/or operation beyond capacity, and concludes that FC indicators are a reasonable proxy for monitoring protozoa but not for helminths, which should be surveyed independently.

Dan Li, Chun Hong Wong, Mei Fang Seet, Nicole Kuan · Frontiers in Microbiology · Singapore

This study conducted, for the first time to the authors' knowledge, an investigation of Stenotrophomonas maltophilia -- an emerging opportunistic pathogen capable of causing high-mortality nosocomial infections in immunocompromised patients while also being ubiquitous in the environment -- on leafy green vegetables and in a hydroponic farming facility in Singapore. Eleven isolates were recovered from three vegetable types (sweet basil, kale, parsley) and the nutrient solution, with high population levels reached in vegetables under abused storage temperatures (over 8-log CFU/ml in basil juice after six days at 20°C) and on hydroponic facilities through biofilm formation (8 to 9-log CFU/well), and UV treatment (over 4-log reduction at 250 mJ/cm²) was identified as an effective measure to reduce contamination in nutrient solutions and facilities.

Sandeep Kumar, Lal Chand Malav, ICAR- National Bureau of Soil Survey & Land Use Planning, Nagpur, 440033, Maharashtra, Shiv Prasad, Sunita Yadav, Amrita Daripa, ICAR- National Bureau of Soil Survey & Land Use Planning, Nagpur, 440033, Maharashtra · Agropedology · Global

This review argues that rapid industrialization and mechanization are driving heavy metal pollution worldwide, with both anthropogenic and natural sources of heavy metals reaching soil, water bodies and plants and ultimately entering the human body through the food chain. Heavy metals accumulate in plants and living organisms after uptake from soil and cause harm, and they are also toxic to soil biological activity by disrupting key microbial processes. The review states that, due to industrial development in urban areas, heavy metal contamination — from metals such as zinc, copper, lead and cadmium — has become a serious threat to the peri-urban agriculture that supplies vegetable production, and it surveys sources of contamination and remediation techniques, with a particular focus on phytoremediation.

S. Alan Walters, Karen Stoelzle Midden · Agriculture · Global

Vegetable production on green roofs faces multiple challenges, resulting in minimal current activity despite its potential for urban agricultural sustainability. While intensive green roof systems are considered suitable for vegetable production, extensive systems with shallow-rooted crops like lettuce, kale, and radish show the greatest potential for sustained productivity due to building weight restrictions. Deeper-root crops like tomatoes require constant monitoring of fertility and moisture. Green roofs are not presented as a total solution for urban food provision.

Michelle Tendai. Chihambakwe, Paramu Mafongoya, Obert Jiri · Challenges · Zimbabwe

This review maps the use of food sovereignty principles in urban and peri-urban agriculture (UPA) in Zimbabwe, addressing its potential for food security. Despite UPA being ingrained in urban households' livelihoods, institutional arrangements governing the practice remain ambivalent. The review underscores that the failure to involve all stakeholders undermines UPA, leading to heightened food insecurity and unsustainable practices.

Robert McDougall, Paul Kristiansen, Romina Rader · Proceedings of the National Academy of Sciences · Australia

This study evaluated small-scale urban agriculture systems in Australia using economic and emergy (embodied energy) analyses. While these systems used land efficiently, they were relatively inefficient in their use of material and labor resources. Benefit-to-cost ratios demonstrated that, on average, the gardens ran at a financial loss, and emergy transformity was one to three orders of magnitude greater than many conventional rural farms. Only 14.66% of all inputs were considered "renewable," resulting in a moderate mean environmental loading ratio (ELR) of 5.82.

Suranga Wadduwage · Journal of Land Use Science · Australia (Adelaide)

A multi-criteria spatially-explicit study in the Adelaide metropolitan area, Australia, investigated agricultural land vulnerability to urban sprawl under opposing policy directions. The study showed higher agricultural land vulnerabilities in “Business-As-Usual” and “Accelerated Economic Development” scenarios, extending into rural areas with a leap-frog effect. This confirms the need to sacrifice farmland uses to maintain land supply for urban development under these conditions.

Khadija Benis, Rukaia Gashgari, Adnan Alsaati, Christoph Reinhart · DSpace@MIT (Massachusetts Institute of Technology) · Saudi Arabia (Riyadh)

The Urban Foodprints (UF) methodology was applied to assess the environmental sustainability of high-yield urban agriculture in Riyadh, Saudi Arabia, focusing on tomatoes. While urban production in high-yield greenhouses could reduce Global Warming Potential by 9% and water savings were significant, the energy needs of these greenhouses were considerably higher than the baseline. This indicates a trade-off where environmental benefits are partially offset by increased energy consumption.

Dona Pickard · International Journal of Sociology of Agriculture and Food · Bulgaria (Plovdiv)

This paper analyzes an urban agriculture case in Plovdiv, Bulgaria, where the municipality cleared over 2 hectares of long-tolerated allotments without involving users, despite NGOs promoting urban agriculture as a social innovation. The case exemplifies barriers hindering social innovation, particularly regarding governance, as the eviction occurred without discussion about the future of urban agriculture. This suggests a lack of civic participation and access to resources for deprived groups.

Georgia Pollard, James Ward, Philip Roetman · Sustainability · Australia (South Australia)

This paper explores the economic sustainability of home food gardens in South Australia using new data from the Edible Gardens project online survey. While saving money is a top motivation for many respondents, the study notes that it remains to be seen whether current gardening practices actually support this aspiration. The paper concludes that more work is needed to measure the full costs of different gardens to better predict their financial accessibility and economic sustainability.

Percy Toriro · · Zimbabwe (Harare)

This chapter explores the governance of urban food production in Harare, Zimbabwe, from 1890 to the present. Evidence indicates that while the practice has gained general acceptance through shifting positions over the years, the status of producers remains uncertain. This uncertainty stems from the lack of full incorporation of urban food production into city plans by planning officials, whose values are out of sync with Harare's lived reality.

Joseph Chabi, Miracle C. Eziefule, Rebecca Pwalia, Joannitta Joannides, Dorothy Obuobi, Godwin Amlalo, Charlotte Addae, Alidu Iddrisu, Dominic Acquah-Baidoo, Samuel Akporh, Sampson Gbagba, Kwadwo K. Frempong, Melinda P. Hadi, Helen Pates Jamet, Samuel Dadzie · Advances in Entomology · Ghana

This study in Accra Metropolis, Ghana, compared Anopheles gambiae s.l. species composition and insecticide resistance between two vegetable-growing and two non-vegetable growing areas. All A. gambiae s.l. populations tested were resistant to five insecticides, with lower mortalities observed in vegetable-growing areas (e.g., 2.6% and 12.5% for deltamethrin) compared to non-vegetable areas (36.2% and 38.9%). Anopheles gambiae s.s. and Anopheles coluzzii were dominant in vegetable-growing areas. The findings indicate that urban agriculture contributes to the development of insecticide resistance, which needs consideration in vector control strategies.

Gaston E. Small, Paliza Shrestha, Adam D. Kay · International Journal of Design & Nature and Ecodynamics · Global

Dissolved phosphorus (PO4 3-) and nitrogen (NO3- & NH4+) losses in leachate from experimental raised-bed garden plots were measured. Plots receiving cow manure compost showed high PO4 3- concentrations (5-11 mg/L), while municipal organics compost plots had concentrations an order of magnitude lower (0.5-1.2 mg/L), and no-compost plots had 0.3 mg/L. Phosphorus lost through leachate and harvest accounted for only 1-10% of total applied phosphorus, indicating soil build-up was the dominant fate. This study illustrates a potential trade-off in urban agriculture between crop production and efficient phosphorus recycling from urban food waste.

Annie Svensson · · Sweden

This research investigated the economic sustainability of 14 Community Supported Agriculture (CSA) farms in Sweden through interviews. The study found that Swedish CSA farms had difficulties covering labor costs and suffered from inefficiency, indicating weak economic sustainability. The study did not identify specific approaches or business models that were more conducive to higher profitability.

Mohamad Assad, Michel Chalot, Fabienne Tatin‐Froux, Valérie Bert, Julien Parelle · Journal of Environmental Quality · Global

This study investigated element transfer in edible crops (cucumber, pepper, cabbage, lettuce) and poplar (Skado cultivar) grown on soils contaminated with sediments dredged from water canals in the 1960s, aiming to develop a biomonitor. The results showed accumulation of cadmium (Cd) and zinc (Zn) in the edible parts of crops, particularly leafy vegetables, indicating that Cd could be ingested in amounts reaching the tolerable daily intake (TDI) in this context. No accumulation of lead (Pb) was detected.

P.S. Bouda, Edmond Hien, A. Dioma, Hyacinthe Kambiré, Yacouba Maïga, Der Adolphe Somé, Sylvie Nazaret, A.S. Ouattara · DOAJ (DOAJ: Directory of Open Access Journals) · Burkina Faso

A study in Ouagadougou sub-urban agricultural fields, Burkina Faso, assessed the impact of using untreated Solid Urban Wastes (SUW) as agricultural fertilizers on soil properties and crop production. SUW amendment significantly increased pH, total C, N, P, and available P, and maize height and biomass yield were 124% and 164% higher in amended plots, respectively. However, trace metal elements (Cu, Zn, Pb, Ni, Cr) concentrations were higher in amended fields, indicating that urban waste carries contaminants posing public health risks.