Research & reports

Khalid Mahmud, Tawhid Hossain, Tamanna Haque Mou, Asraf Ali, Monirul Islam · Turkish Journal of Agriculture - Food Science and Technology · Global

This study evaluated the effect of four nitrogen levels (0, 90, 110, 130 kg N ha-1) on chili growth and yield in a rooftop garden using a Randomized Complete Block Design with three replications. The 110 kg N ha-1 dose resulted in the highest plant height, while the 130 kg N ha-1 dose significantly increased fruit length, fruit yield per plant, average fruit yield per plot, individual fruit weight, and average fruit yield. The findings suggest that applying 130 kg N ha-1 enhances chili plant growth and fruit yield in rooftop gardens.

Paul Sherfey · Budkavlen · Global

This study explores human-animal relationships, particularly with insects, in collective gardens through observation and digital research. It demonstrates that in collective gardens, cultivating community is as important as cultivating organic produce, and this community includes not only humans but also animal species like insects. The article analyzes why gardeners show interest in building hotels and cafes, sowing meadows, and arranging festivals for insects, especially bees, and contrasts discourses about bees with the lack of similar discourse about wasps, considering how different cultural heritages affect the value placed on species.

Govinda Prasad Devkota, Sheri Lee Bastien, Petter D. Jenssen, Manoj K. Pandey, Bhimsen Devkota, Shyam Krishna Maharjan · International Education Studies · Nepal

This Participatory Action Research study in Nepal investigated five teachers' perceptions of using urine diversion dry toilets (UDDTs) and human urine as fertilizer in school gardens. Few teachers accepted human urine as fertilizer, considering it impure and expressing unwillingness to use it on crops. Teachers disliked UDDTs due to perceived bad odor and uncomfortable sitting positions, especially for females, and felt urine as fertilizer was unnecessary.

Theresa W. Ong, Gordon Fitch · · Global

This chapter provides an overview of natural science research methods for new researchers in urban agriculture. It discusses applying classic ecological theory to urban agriculture's unique conditions, identifies open questions, and outlines methodological advancements and pressing issues for future urban agroecological research.

Zornitsa Stoyanova · Economic Alternatives · Bulgaria

This paper aims to determine the possibilities of urban agriculture for improving life quality in Bulgaria, based on an assessment of its ecological impact. It analyzes respondents' opinions on the environmental benefits, customer profiles, product types, and production methods of urban agriculture. Conclusions relate to urban agriculture's potential for food security, resource optimization, green practices, and local employment.

Baptiste Grard, Nastaran Manouchehri, Christine Aubry, Nathalie Frascaria‐Lacoste, Claire Chenu · International Journal of Environmental Research and Public Health · Global

A five-year experimental trial quantified the food production potential, soil fertility, and potential contamination of Technosols created from urban wastes for rooftop edible production. The cropping system showed promising results for food production and maintained high fertility. However, a concern was identified regarding the trace metal content of certain edible crops, specifically zinc (Zn) and copper (Cu), although most trace metal levels were below existing norms.

Alak Barman, Swarna Shome · International Journal of Biosciences (IJB) · Bangladesh

An experiment in Gazipur during 2018-19 investigated the effect of six different ratios of soil and organic materials on strawberry and marigold growth and yield for rooftop gardens. Marigold performed best with 1 kg vermicompost for 1 kg soil (T5), while strawberry showed best performance in most parameters under the same treatment. The lowest yield was recorded from 1 kg cowdung for 2 kg soil (T4).

Joycelyn K. Quansah, Cesar L. Escalante, Angela Parry‐Hanson Kunadu, Firibu Kwesi Saalia, Jinru Chen · Agriculture · Ghana (Accra)

A survey was conducted among 102 urban leafy green vegetable farmers from 12 farming areas in Accra, Ghana, to determine agricultural practices and their association with microbial safety of vegetables produced. It was observed that 70% of farmers used water from waste drains for irrigation, 99% used incompletely composted manure, 96% harvested with bare hands, and over 60% disagreed that polluted irrigation water can contaminate vegetables or make consumers sick. Vegetables cultivated by farmers with no formal education, less food safety knowledge, and those who disagreed about contaminated water causing illness were associated with higher fecal coliform and Enterococcus sp. counts.

Nicolás Caicedo Sarralde · · Colombia (Bogotá)

This investigation used life cycle assessment to determine how urban agroecology in Chapinero, Bogotá, could reduce CO2 equivalent emissions from food production and consumption without affecting nutritional needs. Based on secondary data and a comparison of current and increased agroecology scenarios, the study found that potatoes have high potential in urban agroecology for emission reduction. It also concluded that farm and transport stages have the highest emissions in urban agriculture food cycles, and efficient urban agroecology in Chapinero could reduce CO2 equivalent emissions by 38.99% in nutritionally balanced diets.

Silke Cram, Pilar Fernández, Horacio Carranza, M.C. Gómez Hernández, Claudia Ponce de León, Ana M. Noguez Gálvez · Open Journal of Soil Science · Global

This study evaluated metal inputs, transfer, and translocation in lettuce (Lactuca sativa L.) grown in an urban plot during dry and rainy seasons in 2013, using treated wastewater and rainwater respectively. While soil characteristics and metal transfer/translocation factors varied temporally, leading to different metal concentrations in lettuce tissues, the results indicated that the metal concentration in lettuce tissues posed no harm to human health. However, site-specific studies are necessary for urban agriculture management.

Remigio Paradelo, Antía Villada, María Teresa Barral · International Journal of Environmental Research and Public Health · Global

A two-month pot experiment studied heavy metal transference from five metal-rich urban waste composts and a manure vermicompost to lettuce and Italian ryegrass under controlled conditions. Plant concentrations of Zn, Cu, and Cd increased with their concentrations in compost, while no such relation was observed for Pb. The study found that the ratio of element concentration in plant to compost was much higher for Zn, Cd, and Cu than for Pb, indicating lower bioavailability of Pb.

Ada Górna, Krzysztof Górny · Miscellanea Geographica · Cuba

An exploratory, classification-based study combining fieldwork with satellite and aerial imagery analysis characterized urban agriculture across the built-up areas of Havana, Cuba. It found urban gardens distributed unevenly across the city, concentrated in lower-density districts where land was intentionally left between buildings by modernist planners, with organopónico (organoponics) as the most common production technique — but found that the material commonly used to build the bordering walls of these plots is asbestos, posing a significant health threat to both producers and consumers.

Muhammad Asadullah, Shahbaz Nasir Khan, Hafiz M. Safdar, Rana Ammar Aslam, Imran Shaukat · Earth Sciences Pakistan · Global

A review paper on aquaponics, a closed-loop system combining hydroponics and aquaculture, framed as a sustainable-technology response to soil, air and water pollution, global warming, food shortages and droughts. It notes that many studies have focused on small-scale farming for education and indoor decoration rather than commercial urban-scale food production, and highlights how trickling biofilters and plant uptake of aquaculture wastewater improve water and nutrient use efficiency. The paper identifies the central sustainability challenge as balancing optimal organism growth and maximum production output against minimizing effluent discharge to the environment.

A Shumba, N Dunjana, B. Nyamasoka, P. Nyamugafata, Simon Madyiwa, J. Nyamangara · South African Journal of Plant and Soil · Zimbabwe

In Harare, Zimbabwe, an experiment on sandy and red clay soils tested combinations of cattle manure plus mineral nitrogen fertilizer, 0 or 5 t/ha of mulch, and reduced (RT) or conventional (CT) tillage, assessing effects on soil organic carbon (SOC), aggregate stability, bulk density, steady-state infiltration rate (SSIR) and maize yield over two cropping seasons. Reduced tillage improved SOC and aggregate stability by at least 6% over conventional tillage in the 0-5 cm depth (p < 0.01); cattle manure plus mineral fertilizer increased SOC and aggregate stability by at least 13% and SSIR by at least 17% over mineral fertilizer alone, while mulching improved SSIR by at least 8% and reduced tillage improved it by 27% in both soils. Maize yields increased significantly under mineral fertilizer in both soils (at least 3.7-fold, p < 0.05), and principal component analysis showed yield could be predicted from bulk density in sandy soil and from aggregate stability and SSIR in red clay soil.

Dotanhan Yeo, Kouassi Dongo, Adeline Mertenat, Phillipp Lüssenhop, Ina Körner, Christian Zurbrügg · International Journal of Environmental Research and Public Health · Côte d'Ivoire (Tiassalé)

A 2020 assessment of material flows and greenhouse-gas mitigation from decentralized composting, based on primary data from a pilot composting facility in the municipality of Tiassalé, Côte d'Ivoire. Flows were visualised with STAN version 2.6 (Vienna University of Technology) and carbon emission reductions estimated with UNFCCC methods. In 2017 the station processed 59.4 metric tons of organic waste and produced 14.2 metric tons of mature compost — 24% of input mass on a wet-weight basis and 36% on a dry-weight basis. The compost's nutrient content matched published values for sub-Saharan African compost, and heavy metal contamination met both French and German compost standards. Under this composting scenario, 87% of the baseline emissions that would occur under open dumping could be avoided. The study was motivated by the fact that, despite many composting initiatives across sub-Saharan Africa, data on material flows and mitigation contribution were lacking. It rests on one facility and one year of data and does not address long-term operational continuity or markets for the compost produced.

Wielemaker R., Oenema O., Zeeman G., Weijma J. · Science of the Total Environment, 668:1277-1288 · Global

Drawing on a survey of urban agriculture practitioners in industrialised countries, this study characterises how city-derived resources such as compost, food waste and urine are used as fertiliser and how nutrients are managed. It maps the practices and challenges of cycling urban organic waste back to farmland, systematising on-the-ground approaches that link food-waste composting to urban agriculture.

Tibu C., Annang T. Y., Solomon N., Yirenya-Tawiah D. · International Journal of Recycling of Organic Waste in Agriculture · Ga West, Ghana

In Ga West Municipality, Ghana, stack-pile composting of market waste with sawdust, rice straw and swine manure was monitored for temperature, pH, N, P, K and heavy metal concentrations through the composting process.

Montserrat Delpino-Chamy, María Arquero de Alarcón, Sandra Calduch Fernández, José R. Soto · International Journal of Design & Nature and Ecodynamics · Chile (Concepción)

This research focused on developing and applying a methodology to identify and assess agroecological practices in the metropolitan area of Concepción, Chile. A methodology based on production forms, sociopolitical organization, and metropolitan sustainability was proposed. Strengths identified include their location in rururban interstices and small scale, contributing to metropolitan sustainability. However, weaknesses include a lack of appropriate planning policies and regulations, threatening their existence under urban development pressures.

Rayim Wendé Alice Nare, Stephania Boua, Rockia Marie Nadege Zerbo, Richard Madege · Research Journal of Science and Technology · Burkina Faso

This study assessed the impact of urban waste application on soil microbial activities in Burkina Faso. Soil amended with urban waste showed significantly higher Soil Induced Respiration (SIR) (0.049 mg C g−1 soil h−1) compared to manure-amended (0.0212 mg C g−1 soil h−1) and control soils (0.0114 mg C g−1 soil h−1). Urban waste amendment also significantly decreased lag time by 50% and maximal response time (Tmax) by 53%, indicating increased microbial biomass and rapid growth of soil microorganisms. The results suggest that adding urban waste to soils is likely to result in carbon sequestration.

Simon Tresch, David Frey, Renée‐Claire Le Bayon, Paul Mäder, Bernhard Stehle, Andreas Fließbach, Marco Moretti · Scientific Reports · Switzerland (Zurich)

A study in 85 urban gardens across Zurich, Switzerland, investigated the impact of gardening on five soil functions and the relationship between plant (600 spp.) and soil fauna (18 earthworm spp., 39 springtail spp.). High plant diversity positively affected soil fauna and multifunctionality, but intense garden management decreased plant diversity. This indicates a trade-off where intensive gardening, while potentially beneficial for some aspects, can negatively impact overall plant diversity.

Gaston E. Small, Sara Osborne, Paliza Shrestha, Adam D. Kay · International Journal of Environmental Research and Public Health ·

This study measured phosphorus (P) concentrations in native soil below four- and six-year-old urban garden plots, collecting soil cores from five plots of each age. It found that inorganic weakly exchangeable P was significantly elevated in native soil below garden plots (>35 cm deep) compared to reference profiles, indicating accumulation of excess P from compost. This suggests that while urban agriculture can recycle P, over-application of compost may contribute to soil and water pollution.

L.C. Obuseng · Botswana Journal of Agriculture and Applied Sciences · Botswana (Gaborone)

This review highlights the potential for heavy metal accumulation in soil and crops from urban and peri-urban agriculture (UPA) around Gaborone, Botswana, due to the intensive use of chemical fertilizers, pesticides, wastewater, sludges, and industrial effluents. A literature review showed that fertilizers contain heavy metals, and the use of treated or untreated sewage water by UPA farmers can lead to heavy metal accumulation in soil and crops, posing a danger to human health. Information on heavy metal accumulation in soils is limited in Botswana, despite high agrochemical use in UPA vegetable production.

Wendy Johanna Murcia Gulumá, Óscar Andrés Pérez Soler, Sindy Rodríguez Rodríguez · · Colombia (Bogotá)

This study provided advisory support to an urban garden in Bogotá, Colombia, named "Guerreros y Guerreras Unidos en Accion," which had been operating empirically since 2005 without formal legal status or strategic planning. The garden, primarily involving individuals over 50 without formal employment, sought to formalize its activities by establishing a foundation. The intervention aimed to guide the garden's members through the legal and administrative steps for formalization.

Theresa Brehm · Iowa State University Digital Repository (Iowa State University) · Uganda

This study, conducted at Naluwoli Primary School garden in Kamuli district, Uganda, tested the decomposition of household items as an inexpensive indicator of soil health. Cotton underwear, green and rooibos teas, and birch wood sticks were buried for 4, 7, 14, and 21 days in hand-tilled and untilled soils. Untilled soils decomposed cotton by 0.68% less and birch wood sticks by 0.86% more per day than hand-tilled soils, while tea data was inconclusive due to outside biological factors.

Rafael Bújanos Muñíz · · Global

This essay explores the intersection of permaculture principles and their potential application in urban agriculture. Permaculture, originating from the work of Bill Mollison, David Holmgren, and Masanobu Fukuoka in the 1970s, is a system for designing and implementing general principles for organic food production in urban settings. It is based on natural ecosystem patterns and ethical principles, including soil, forest, and water conservation, self-care, and equitable distribution of goods with reasonable consumption limits.