Research & reports

Marjorie Tendero, C. Guyot · HAL (Le Centre pour la Communication Scientifique Directe) · Global

This article discusses the booming urban composting sector, driven by urban agriculture's new outlets for organic materials. Individual or collective composting offers a decentralized solution with positive impacts on the environment and neighborhood social relations. Its success requires material availability in common spaces, communication systems, support for residents' initiatives, and consideration of technical, ecological, agricultural, economic, and social aspects.

Candis M. Hunter, Dana Williamson, Melanie Pearson, Eri Saikawa, Matthew O. Gribble, Michelle C. Kegler · Local Environment · United States (Atlanta)

This study used five focus groups with Atlanta community garden leaders to investigate perspectives on composting, hygiene, and mulching, which are practices to reduce exposure to soil contaminants. Gardeners cited a need for more funding, volunteers, and training. A primary barrier to composting and mulching was concern about contamination of source materials, and participants did not directly link these practices to reducing soil contaminant exposure. Hygiene challenges included concerns about beneficial bacteria, inadequate water access, and limited supplies.

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.

Nur Farzana Ahmad Sanadi, Chew Tin Lee, Mohammad Roji Sarmidi, Jiří Jaromír Klemeš, Zhenjia Zhang · DOAJ (DOAJ: Directory of Open Access Journals) · Global

This study characterized the physical and nutrient properties of liquid fertiliser (compost leachate and compost tea) derived from different bio-waste composts and sought to establish a correlation between their nutrient composition and that of the resulting solid compost. It found that the liquid fertiliser contains nitrogen, potassium and phosphorus essential for plant growth but requires dilution or pre-treatment before use due to high organic content, and developed a formula, using graphical analysis and simple linear regression, that predicts solid compost nutrient composition from analysis of the liquid fertiliser.

Arne Backlund, Annette Holtze · Linnaeus Eco-Tech · Europe

A report on one of several wastewater projects run since 1998 by Storstrøm County and A & B Backlund ApS in Denmark, examining source-separating (diverting) toilet technology and the composition of collected human urine mixture and composted faeces, carried out under an Action Plan administered by the Danish Environmental Protection Agency. User experience in the Danish projects shows the diverting technology is accepted in housing areas, works well in public places, and is highly appreciated in allotment gardens, though further technical improvement is still needed. Comparing the collected urine mixture's nutrient, heavy-metal, organic-compound and microorganism content against organic fertilizers used in Danish agriculture, the analyzed urine mixture was found to be of high quality.

Jeltsje de Kraker, Katarzyna Kujawa-Roeleveld, Marcelo Villena, C.P. Pabon Pereira · Sustainability · Global

A case study of Peñalolén, Santiago, Chile, examining the potential for decentralized recovery of nutrient-rich residual urban waste flows — organic matter, nitrogen and phosphorus — using technical and socio-economic criteria. Kitchen waste, garden residues and urine were treated as system inputs, with urban agriculture, municipal green space and peri-urban agriculture as destinations for recovered nutrients; the technologies studied were anaerobic digestion, vermicomposting, composting, and urine storage with struvite precipitation. Material flow analysis compared the inputs and outputs of the traditional centralized waste management system against household- and municipality-level decentralized valorization scenarios. The findings show that decentralized valorization of kitchen and garden waste reduces landfill fees and waste-transport costs compared with the current centralized system.

Prof. P. R. Khobragade · International Journal of Trend in Scientific Research and Development · Global

This project implemented and analyzed a green-campus initiative at the BDCE engineering college in Sevagram, India, involving vermicomposting of paper waste and plant matter, reducing plastic use, using solar energy, harvesting rainwater, and introducing a community garden. Water quality testing on campus confirmed the water was potable, solid waste was shown to be reducible through composting methods, and applying the 3R principle (reduce, reuse, recycle) along with maintaining campus greenery through the project's techniques produced favorable results.

Intergovernmental Panel on Climate Change (IPCC) · IPCC National Greenhouse Gas Inventories Programme (IGES) · Global

This IPCC guideline chapter sets out the First Order Decay (FOD) methodology for estimating methane emissions from solid waste disposal sites. The default fraction of degradable organic carbon that decomposes (DOCf) is 0.5 for bulk waste and 0.7 for food waste. For high-moisture, rapidly degradable waste such as food waste, k=0.2 (half-life of about 3 years) is indicated, versus k=0.02 (half-life of about 35 years) for dry, slowly degradable waste.

Vergara, S.E., Silver, W.L. · Environmental Research Letters · United States

A study measuring greenhouse gas emission patterns and emission factors from windrow composting of organic waste. The methane emission factor was 1.7 ± 0.32 g CH4/kg wet feedstock, CO2 was 19 ± 3.7 g CO2/kg, and nitrous oxide was below instrument detection limits. Life-cycle emissions, accounting for avoided emissions and carbon sequestration, were negative at −690 g CO2-e/kg, indicating a net mitigation benefit.

C40 Cities Climate Leadership Group · C40 Cities · China

This case study describes how Chengdu's Xingrong community converted an unused rooftop space into a vegetable garden in 2014. The project uses three environmentally friendly methods—rainwater irrigation, food-waste composting, and natural pest control—with 23 of more than 50 households participating in shared cultivation and harvest distribution.

Jiménez-Antillón, J., Calleja-Amador, C., Romero-Esquivel, L. G. · Resources (MDPI), 7(4):84 · Global (Costa Rica; Japan-origin method)

A field study placing the Kitakyushu-origin 'Takakura' composting method—widely diffused in Surabaya, Indonesia—as small portable boxes in university offices and workplaces in Costa Rica. Processing food waste from 45 staff over six months, it shows that low-cost, citizen/workplace-scale fermentation composting is viable.

Sabki M.H., Lee C.T., Bong C.P.C., Klemeš J.J. · Chemical Engineering Transactions, 70:49-54 · Asia (Indonesia, China)

Cost-benefit analysis of composting operations across Indonesia, China and Asian countries, evaluating economic viability of circular economy approaches in urban farming.

Elizabeth A. Miernicki, Sarah Taylor Lovell, Sam E. Wortman · Urban Agriculture & Regional Food Systems · United States (Illinois)

A 2-year field experiment in Illinois compared urban production systems (direct soil, compost-only raised beds, and mixed compost-and-soil raised beds) and fertilizer sources for their effects on growing media, weeds, and vegetable yields. Compost raised beds had higher pH, organic matter, and nutrients and sharply reduced weeds, and the authors recommend raised beds with a mix of compost and soil for urban vegetable production.

Blake T. Moskal, Sean T. Berthrong · Urban Agriculture & Regional Food Systems · United States (Indianapolis)

The study tested a barrier strategy used by urban farmers in Indianapolis—layering wood chips between contaminated or low-quality background soil and healthy growing media—for protecting urban growing beds. Despite a limited sample, barriers appeared effective at separating contaminated soils from growing beds, and farming with barriers or in non-contaminated soil improved soil nutrients and physical characteristics, though phosphorus was very high in many beds, posing a potential risk to waterways.

Burghardt W., Schneider T. · Journal of Soils and Sediments · Germany (Ruhr)

Analysed pH, bulk density, and contents/stocks of organic carbon, nitrogen and heavy metals (Pb, Cd, Zn, Cu, Ni) in vegetable patches, lawns and compost heaps across fourteen gardens in four allotments of the northwestern Ruhr area.

Burghardt W., Heintz D., Hocke N. · Eurasian Soil Science · Germany (Ruhr)

Compared vegetable-garden soils with surrounding arable land in the central Ruhr area, analysing horizons, texture, pH, bulk density, C/N ratio, and stocks of organic carbon, nitrogen and available nutrients.

· International Journal of Recycling of Organic Waste in Agriculture · Global

Evaluates the efficiency of the epigeic earthworm Eisenia foetida in vermicomposting different organic substrates, including kitchen waste.

Universidad Tecnológica Fidel Velázquez, Alfredo Ricardo Pérez Fernández, Mariana Ruiz Morales, Universidad Iberoamericana, María Odette Lobato Calleros, Universidad Iberoamericana, Eloy Pérez Valera, Biosistemas Sustentables, S. A., Promotora de Inversión de Capital Variable, Perla Rodríguez Salinas, Universidad Tecnológica Fidel Velázquez · Revista Internacional de Contaminación Ambiental · Global

This study developed biophysical substrates for protected and urban agriculture by mixing compost from urban solid waste with polystyrene and tepetate. Experimental tests were conducted on roses and tomatoes under four different treatments in a greenhouse, evaluating substrate nutritional properties and productivity. The results indicate that the proposed biophysical substrates possess physical, chemical, and biological properties making them a viable substitute for urban gardening or protected agriculture.

Lisbeth Gallardo, Yelitza Contreras, J. Saavedra Jaramillo, Raúl Ernesto Alban · Cadernos de Agroecologia · Venezuela

This paper investigated the population growth index of the Red Californian Earthworm (Eisenia foetida) to produce solid and liquid humus from urban organic waste. Conducted at the Artisanal Bioisumes Laboratory at the Bolivarian University of Venezuela, the study compared compost and egg shells with coffee waste as substrates. The egg shell and coffee waste substrate yielded better earthworm population growth and humus production.

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.

Janaina Henrique dos Santos, Júlio César Maestri · Cadernos de Agroecologia · Brazil

This work presents the experience of reapplying the "Revolution of the Baldinhos" Social Technology, which involves managing organic residues and urban agriculture, in Macaiba-RN, Brazil. The project focuses on women collecting household organic waste to produce thermophilic static compost for urban food production and gardening. This method, originating from the UFSC Method, was applied through the Urban Housing Project with Social Technology (MUTS), supported by AACC/RN and Banco do Brasil Foundation, marking its first national application.

Rayssa da Rocha Batista, Aparecida Hurtado Soares, Carolina Simões dos Santos, Henderson Gonçalves Nobre · Cadernos de Agroecologia · Brazil

In Capitão Poço, PA, urban and peri-urban farmers cultivate vegetables for subsistence and surplus sale. The NEA/UFRA/Capitão Poço/PA has supported these farmers by providing information on agroecology principles and building participatory knowledge on sustainable vegetable production technologies. This initiative included three training workshops on agroecological production systems, covering biofertilizer production, composting, and vermicomposting, fostering learning and knowledge exchange.

Renee Raiden Boyer, Ben Chapman · VTechWorks (Virginia Tech) · Global

This handbook outlines recommended agricultural practices for food safety in school and community gardens. Topics include food safety, site selection, pesticides and fertilizers, handwashing, water and irrigation, composting, garden design and animals, sanitation, and tools.

Rodrigo Vanderlan do Nascimento, Ajibola Isau Badiru, Luiz Agberto Fragoso De Oliveira · REMEA - Revista Eletrônica do Mestrado em Educação Ambiental · Brazil (Maceió-Alagoas)

This study explored the pedagogical possibilities of using a composter for biofertilizer production as an interdisciplinary teaching resource in the school garden of Monte Sinai College in Maceió-Alagoas, Brazil. Employing a qualitative, exploratory research approach with observational data analysis, it identified educational benefits in environmental projects. The process utilized mango tree residues from the school as primary biomass generators for the composter.

Fabiola Mejía, Clara Liliana Montero, Lina Marcela Arango, Emily Johanna Bermúdez · Letras ConCiencia TecnoLógica · Colombia (Bogotá)

At the Escuela Tecnológica Instituto Técnico Central (ETITC) in Bogotá, Colombia, a process for utilizing organic waste through composting was implemented. Following an "Urban Agriculture" workshop, organic waste from the ETITC cafeteria was collected and identified. Different mixtures were created to produce compost, which was then used in seedbeds and for transplanting seedlings. This research aimed to demonstrate the potential of using organic waste for compost production.