Research & reports

GOMGNIMBOU Alain P. K., COULIBALY Kalifa, SANON Abdramane, BACYE Bernard, Hassan NM, Sedogo P. Michel · Zenodo (CERN European Organization for Nuclear Research) · Burkina Faso

This study aimed to chemically characterize organic fertilizers used in urban agriculture in Bobo-Dioulasso, Burkina Faso. For this purpose, seven animal-based fertilizers were analyzed.

Blake Baldwin, Kathleen Koenig, Andries Van der Bent · The Science Teacher · United States

This article describes a partnership between an urban, Midwestern STEM high school, a local university's Engineers Without Borders (EWB) chapter, and a nonprofit organization. In spring 2014, an engineering design unit was developed for high school juniors in a Principles of Engineering course to update compost bins for a community garden. The unit integrated science content with engineering practices, aiming to help students understand conservation, learn the science behind composting, and design effective compost bins to meet the client's needs.

William Kort · UWM Digital Commons (University of Wisconsin–Milwaukee) · United States

This study developed a framework for life cycle environmental assessment of urban organic waste utilization in urban agriculture, specifically fruit and vegetable production. Results suggest that a full "urban nutrient cycle" offers significant environmental benefits, including meeting up to 70% of vegetable and 17% of fruit consumption needs in Northern and Eastern U.S. cities, with potential water savings of 10-17% of annual domestic use. Optimizing resource recovery through source separation leads to 1-2% lower wastewater generation and up to 44% greater phosphorus recovery, while overall energy and emissions benefits are 1-2% of a city's annual totals.

Rosanne Wielemaker, Jan Weijma, G. Zeeman · Resources Conservation and Recycling · Netherlands (Rotterdam)

This paper assesses the match between supply from New Sanitation (NS) systems and demand from Urban Agriculture (UA) for nitrogen, phosphorus, and organic matter in Rotterdam. Using the Urban Harvest Approach, the research found that UA's demand for nutrients and organic matter can be minimized by 65–85%, achieving 100% self-sufficiency for phosphorus and partial self-sufficiency for nitrogen and organic matter. The integration of NS and UA maximizes urban self-sufficiency.

Gundula Proksch · · Global

This chapter discusses urban agriculture as a holistic approach to nutrient resource management in cities, aiming to reestablish closed-loop systems for nutrient recycling. It provides knowledge on aligning plant nutrient needs with efficient growing systems and recycling strategies like composting and anaerobic digestion. The chapter also illustrates the potential integration of these systems into building designs and their impact on building performance.

Talita Slota Kutz, Fernanda Daniela Bandelero, Jéssica Cardoso, Thiago de Olivera Vargas · · Brazil

This work describes a 16-hour theoretical-practical workshop conducted in a settlement in Peritoro-MA, Brazil, during the "Operacao Velho Monge" of Project Rondon in 2014. The workshop aimed to disseminate agroecological horticulture through the implementation of a pilot community garden project with drip irrigation and composting systems, facilitating learning for both the settlement community and participating students.

Valerie Chiykowski, Guhan Chendurnathan, Jun S. Lee, Lius Daniel · cIRcle (University of British Columbia) · Canada

This project at the University of British Columbia's Student Union Building (SUB) aimed to reduce contamination in post-consumer organics bins using visual prompts. While the intervention successfully decreased both the percentage weight and level of contamination, the overall weight of compostable waste also decreased post-intervention. The study suggests considering confounding factors like a sustainability fair during baseline data collection and improved bins, and proposes an infrared sensor-based audio prompt system for future efforts.

Naomi Shimpo, Toru Terada, Makoto Yokohari · Journal of The Japanese Institute of Landscape Architecture · Japan

This study examines the feasibility of organic material circulation from turning increasing vacant lots in suburban Japan into allotment gardens, comparing three scenarios with different degrees of gardenization. Composting experiments identified the composition of organic materials needed to produce usable compost and the amount of compost required to gardenize vacant lots, while a separate analysis determined how many households would need to cooperate in supplying organic materials under each scenario. The study found that the weight ratio of kitchen waste to pruning waste for usable compost was 3:2, and that cooperation from at least 16 households would be needed to produce enough compost to gardenize an average-sized housing lot. It concludes that the scenario limited to existing gardens on vacant lots is feasible for organic material circulation, while the other two scenarios, which assume more extensive gardenization, would require greater understanding among urbanites.

Shlrene Quaik, Kaizar Hossain, Mahamad Hakimi Ibrahim · International Journal of Agricultural Research · Global

Liquids derived from vermicomposting of pre-composted cow dung—vermiwash and vermicomposting leachate—were diluted to prevent leaf scorching and applied to sweet potato as a foliar treatment. Chemical analysis confirmed the presence of plant nutrients, and increases in chlorophyll content (chlorophyll a, b and total) and improved nutrient distribution in sweet potato leaves were observed. The results indicate vermiwash and vermicomposting leachate have potential as organic foliar fertilizers, and their application in field-scale urban farming fertigation is feasible, though enriching their nutrient content further would require adding other nutrient-rich substrates.

Sandra Yamile Salamanca Corredor, Brayan Osnaider Diaz Morales · · Colombia

This pilot study, focused on the La Estancia neighborhood of Bogotá, assessed the technical and economic feasibility of implementing home practices for utilizing household waste -- (1) vermiculture for organic waste, (2) urban agriculture and vertical gardens, and (3) reuse of greywater for non-potable uses. It also investigated whether residents of the neighborhood already use these practices for managing waste and greywater, and their level of interest in the topic.

Joshua W. Beniston, Rattan Lal, Kristin L. Mercer · Land Degradation & Development · United States (Youngstown)

In Youngstown, Ohio, this study measured soil and plant responses to organic-matter amendments made from yard wastes and to raised beds on vacant lots where houses had recently been demolished. Two years after application, the amendments significantly improved soil physical, chemical, and biological properties and increased vegetable yields, with a soil quality index comparable to rural agricultural soils. The results indicate urban agriculture can be productive on vacant land and that yard-waste amendments can restore degraded urban soils.

Abdul‐Halim Abubakari, Laura Atuah, B. Banful, Hypolite Bayor · Journal of Soil Science and Environmental Management · Ghana

A study in Ghana reviewed literature and surveyed farmers on soil amendments for urban horticulture. The review found that research on soil amendments has been limited to land management and nutrient recovery, not addressing quality issues for specific production systems. Farmers adopt varying application rates due to lack of standardization, and barriers include technology for collection, funds for purchase, and labor employment.

David Mkwambisi, Andrew J. Dougill, Philip Antwi‐Agyei, C. P. Chabvuta · CABI eBooks · Malawi

Research in Lilongwe and Blantyre, Malawi, assessed urban agriculture's potential to improve soil quality, crop yields, and livelihoods. Preliminary evidence showed urban waste could address food insecurity and soil nutrient benefits, but several constraints in waste management were identified. City authorities are not proactively utilizing organic municipal waste for soil quality and agricultural production benefits.

Baptiste Grard, N. Bel, Marchal, Nicolas, Frédéric Madre, Jean‐François Castell, Philippe Cambier, Sabine Houot, Nastaran Manouchehri, Stéphane Besançon, Jean‐Charles Michel, Claire Chenu, Nathalie Frascaria‐Lacoste, Christine Aubry · Kobra (Universitätsbibliothek Kassel) · France (Paris)

A 2012 pilot experiment in Paris, France, tested simple rooftop gardening systems using local urban organic waste as crop substrates. Measurements of production levels and heavy metal content in crops and substrates showed high crop production with limited inputs, low heavy metal pollutants in edible parts, and positive yield influence from layered substrates and earthworm inoculation. These results suggest rooftop gardening is feasible and has potential for urban resiliency, though further assessment of roof types, pollution levels, and sustainability is needed.

Klaus Lorenz · Soil Science · Global

Urban agriculture (UA) engages approximately 800 million people globally and covers over 67 million hectares of urban cropland. While UA contributes to food security, growing food in urban ecosystems, particularly on degraded urban soils, presents challenges. Past research on UA has focused on social sciences, and although studies on urban soils have increased, many urban areas remain neglected. Further research and dissemination of knowledge are needed on how to maintain or enhance urban soil fertility through soil and land-use management practices.

Tovonarivo Rafolisy, Heriniaina Ramahefarison, Dominique Massé · · Madagascar (Mahajanga)

Two experiments in Mahajanga, Madagascar, compared municipal solid waste (MSW) composts with conventional organic inputs (poultry or pig manure) in leaf cropping systems over two three-month seasons. MSW composts resulted in yields higher than pig manure and urea, and similar to poultry manure. However, monitoring soil mineral nitrogen levels revealed significant accumulation under certain conditions, indicating a possible source of environmental pollution by nitrates.

А А Золотаревский, И И Прокопович · Лесной вестник / Forestry bulletin · Russia (Moscow)

This article explores the potential of composts made from woody-plant waste (WPW) as an alternative to expensive organic additives for urban gardening in Moscow. It suggests that composting WPW can provide a cost-effective solution for preparing fertile soil, which is crucial for plant survival in urban environments. Modern composting technologies allow for the mechanization of WPW composting, producing vegetable earth suitable for planting trees.

J.S.C. Wiskerke · · Global

This chapter focuses on urban food supplies and the challenges of managing waste flows from urban households and markets in developing countries. Large amounts of municipal solid waste, human excreta, and wastewater are produced, most of which end up in non-engineered landfills or pollute the urban environment. It is noted that these wastes pollute the urban environment, especially in low-income countries with less developed sanitation infrastructure.

Angela Y. Y. Kong, Cynthia Rosenzweig, Joshua Arky · HortScience · United States

This study evaluated the effects of organic and inorganic nitrogen (N) inputs on N dynamics within substrate typically used on rooftop farms during an 8-week greenhouse experiment in the United States. Substrate without added N inputs (control) was compared with synthetic fertilizer and three organic N inputs: composted poultry manure, municipal green waste compost, and vermicompost. Few differences in N cycling and yields were found among treatments receiving organic N inputs, despite differences in carbon-to-nitrogen ratios. Crop yields from the synthetic fertilizer and municipal green waste compost treatments were higher than other organic N input treatments. Inorganic N levels in the synthetic fertilizer treatment decreased from 129 mg N/L to 113 mg N/L, while control and organic N input treatments showed nearly 10-fold decreases from 79.5–117.8 mg N/L to 12.8–16.6 mg N/L over 8 weeks. The greatest losses of ammonium and nitrate via leachate were measured from the synthetic fertilizer treatment.

Geneviève S. Metson, Elena M. Bennett · Elementa Science of the Anthropocene · Canada

A study of Montreal, Canada, examining the potential and barriers for phosphorus (P) recycling through organic waste, noting that currently only 6% of P in Montreal's waste is recycled. Combining semi-structured interviews with 19 key stakeholders, participant observation over more than 1.5 years, and document review, the study identified key barriers and facilitators to achieving a high level of organic waste recycling through composting. A provincial law mandating 100% recycling of organic matter was found to have great potential to facilitate increased P recycling, but this potential is inhibited by a lack of shared vision about the roles of government, the private sector, and citizens in producing high-quality compost, along with cultural inertia, lack of knowledge, and lack of infrastructure. Urban agriculture, which benefits from strong citizen support and is both a consumer and producer of compost, could help overcome some of these barriers, but limited access to garden space and training, and diversity in the fertiliser qualities gardeners want, somewhat limit this potential.

Tainã Coelho Quevedo, Anilton Squena de Oliveira, Lauren Machado Gayeski, Marcelo Pereira de Barros · DOAJ (DOAJ: Directory of Open Access Journals) · Brazil

Through Universidade Feevale's participation in Brazil's Projeto Rondon, workshops presented concepts and methodologies for developing community gardens and reusing organic waste and rainwater in two locations in Maranhao state. Three lectures were given and four community gardens, four composters, and two cisterns were built across four municipal schools, training 97 people. Environmental multipliers were trained through active community participation, and alternative cost-reduction techniques were made available for economically disadvantaged regions.

Ermolaev E., Sundberg C., Pell M., Jönsson H. · Bioresource Technology · Sweden

Measures CH4, N2O and NH3 emissions from home composts in practice in Sweden; methane emissions were lower than in large-scale systems and increased with temperature and mixing.

Emmanuelle Vaudour, Christine Aubry, Liliane Bel, Laëtitia Bréchet, Philippe Cambier, Yves Coquet, Karim Dhaouadi, Veronique V. Etievant, Benoît Gabrielle, Jean-Marc J.-M. Gilliot, Jean Christophe Gueudet, Dalila Hadjar, Jonas Hamiache, Sabine Houot, Christophe Labat, Patricia Laville, Raia Silvia Massad, Joël Michelin, Paul Emile Noirot Cosson, Jean-Noël Rampon · HAL (Le Centre pour la Communication Scientifique Directe) · France

The PROSTOCK project aimed to spatially assess the potential of recycling organic waste (exogenous organic matter, EOM) to improve soil organic carbon stocks (SCS) in peri-urban agricultural areas. It also evaluated the impacts of EOM use on greenhouse gas emissions and nitrate leaching. The Versailles Plain and Alluets Plateau (221 km²) were chosen as the study region, with field and lab measurements collected from over 250 point locations. The project advanced the use of imaging data for estimating topsoil organic carbon content (SOC) from soil reflectance spectra, but found that medium spatial resolution multispectral satellite images do not discriminate changes in SOC resulting from EOM applications.

Olle Lind · · Sweden (Malmö)

This study tested bokashi fermentation leachate from four food waste sources in Malmö and Lund, Sweden, on pak choi in sand, garden waste compost, and peat substrates to evaluate its potential as a biofertilizer in urban farming. The leachates were generally low in nitrogen, leading to poor plant growth in nitrogen-poor substrates, though they were high in potassium and phosphorus. Avoidable food waste contained higher sodium and chloride than unavoidable food waste, suggesting unavoidable food waste is a more suitable source for bokashi leachate fertilizer.

Yuki Sampei, Yuji Hara, Akinobu Murakami, Armand PALIJON, Kazuaki Tsuchiya, Makoto Yokohari · Journal of The Japanese Institute of Landscape Architecture · Philippines (Metro Manila)

The nitrogen supply-demand balance in compost and vegetable production on vacant lots in suburban residential districts of Quezon City, Metro Manila, was assessed. Analysis revealed that almost half of the subdivisions faced nitrogen oversupply, while several were in short supply. Current centralized composting facilities may not adequately support a continuous compost recycling system due to their distribution patterns. It was proposed that existing barangay-based policies on organic waste management and urban agriculture require greater flexibility and attention to coordination systems across subdivision boundaries.