Research & reports

Stéfanny da Cruz Nóbrega, Lara Cristine Gomes Ferreira · OKARA Geografia em debate · Brazil (Goiânia)

This article presents results from a university extension project between the Federal University of Goiás and elementary school students in Goiânia, Brazil. The project focused on socio-environmental education through an agroecological school garden, integrating theory and practice with didactic sequences on agrarian geography topics like food consumption awareness, socio-biodiversity, traditional knowledge, and soil management. Activities included workshops on vertical gardens and composting, a soil workshop, and field trips, aiming to exchange knowledge on agricultural production forms, agroecology, and food sovereignty, valuing family farming.

Ahmad Rifqi Fauzi, Warid Warid, Maulidian Maulidian · Khadimul Ummah · Indonesia (Jakarta)

Since 2016, Trilogy University's Community Partnership Program has disseminated urban agriculture technology and empowered residents of the West Jatinegara Flats in Jakarta, Indonesia. This initiative supports the DKI Jakarta provincial government's urban farming program, aiming to enhance food security and reforestation. Activities included training in vertical farming, composting, and utilizing open land, resulting in residents becoming familiar with urban farming technology and the implementation of hydroponics for net houses.

Sugeng Triyono · · Indonesia

This study observed the effect of medium size and organic compost dosage on the growth and yield of red lettuce (Lactuca sativa L. var red rapids) in pots. A 3x4 factorial treatment in a completely randomized design with 3 replicates tested medium sizes (1kg, 3kg, 5kg) and organic compost dosages (0%, 10%, 30%, 50%). Results showed that red rapid lettuce growth was depressed at 1kg and 3kg medium sizes but grew more freely at 5kg. The treatment combination of 3kg medium size-10% compost dose, yielding 75.3g per plant, was considered the most optimum due to using the least amount of medium and compost, despite restricted growth.

Fetty Dwi Rahmayanti · · Indonesia (Jakarta)

This research focuses on utilizing waste chicken and duck eggshells as organic fertilizer for shallot plants cultivated in pots, particularly in Cipinang Melayu Village, East Jakarta, Indonesia. The study aims to process eggshell waste into eggshell flour fertilizer to provide nutrition for shallot plants. During the research, each stage of shallot growth and development will be observed from planting to harvesting.

Udhayabanu.D, Sharmilabanu.D · Studies in Indian Place Names · India

This study investigates rooftop farming in an urban area in India, focusing on the growth ratios of two plants cultivated using different substrate ratios, including garden soil and kitchen waste compost. Measurements included stem height, leaf height, girth, root height, and total growth time. The study suggests that rooftop cultivation contributes to environmental sustainability by increasing green cover, reducing carbon levels, and decreasing household organic kitchen waste.

Wahyu Sulistiadi, Ibnu Malkan Bakhrul Ilmi, Dian Luthfiana Sufyan, Sri Rahayu · Jurnal Bisnis Indonesia · Indonesia (Depok)

A community service activity in Depok, Indonesia, aimed to establish vegetable consumption habits among residents by utilizing limited space for verticulture. The training employed organic and non-organic waste as growing media, using participatory methods and demonstrations. Participants practiced planting vegetables from seeds to harvest using verticulture, and the activity was deemed successful as most participants were able to harvest their own crops.

Yoshiki HARADA, Thomas H. Whitlow, Nina Bassuk, Jonathan Russell‐Anelli · Frontiers in Sustainable Food Systems · United States (New York City)

This study compared various soil mixes for rooftop farms to assess stormwater retention, yield, and quality of drought-sensitive crops. A 5-week greenhouse experiment cultivated leaf lettuce using an irrigation rate mimicking average growing season precipitation for New York City, comparing five soil mixes made of coconut coir, biochar, and animal manure compost, plus a commercial rooftop farm soil. Three soil mixes showed good yield with water retention rates up to 100%, and drainage nitrogen output levels were less than 13% of current levels at an operational rooftop farm in NYC.

Ornela María Muñoz Millet, Antonio Yepes Jiménez · · Spain

A school in Spain implemented composting of organic waste from its canteen for use in an ecological school garden, with support from the AGROA school composting program and the Aguilas City Council. The entire educational community participates, from canteen staff separating waste, to the janitor transporting it, and teachers and students organizing it for compost and using it as fertilizer. This practice serves as a didactic resource for developing environmental attitudes and sustainable habits.

Pawan Gajbe · Agricultural Science Digest - A Research Journal · India (Nagpur)

An experiment was conducted in Nagpur city, India, from July 2019 to March 2020, to grow herbs and vegetables on a 230 sq ft rooftop area. The experiment produced 61.7 kg of pesticide-free vegetables using sustainable farming methods, including cultural pest management, composting household green waste, and irrigating with harvested rainwater and greywater. The results indicate that sustainable urban rooftop farming can be an innovative means to promote urban agriculture without harming the environment.

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.

Hillary A. Craddock, Elisabeth Fost Maring, Stephanie Grutzmacher · African Journal of Food Agriculture Nutrition and Development · Ethiopia

A mixed-methods pilot survey of 21 teachers and parents in Debre Berhan, Ethiopia, investigated household agricultural practices to understand foodborne illness risks. The study found that half of respondents using manure applied uncomposted manure as fertilizer, and many kept multiple animal species. This suggests a high risk of pathogen exposure for children and adults through contact with uncomposted manure and animals.

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).

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.

Madeleyne Ivonne Demera-Pico, Carlos Francisco Ortega-Ordóñez · Dialnet (Universidad de la Rioja) · Spain

A study reporting the incorporation of substrate into an ecological garden while applying strategies for organic production. Solid waste was sorted and organic waste used to develop three types of compost: the first from humus-rich soil with 10% sandy soil, the second from silty soil with 20% sandy soil, and the third from silty soil with 40% sandy soil, aimed at improving water filtration and moisture retention. Each compost was combined with production strategies using biostimulants and ecological micro- and macronutrients, and irrigation water was monitored for chlorine concentration and pH before use. The compost made from silty soil with 40% sandy soil, combined with 5 mL of a biostimulant that adjusted alkaline water to neutral pH, produced the greatest increase in soil fertility and the best improvement in germination, cultivation, and post-harvest development.

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.

Pai S., Ai N., Zheng J. · Sustainable Cities and Society, 50:101683 · United States

Using Chicago as a case study, this analysis assesses the feasibility of decentralized community composting on portions of public parks in terms of cost and greenhouse gas emissions. It finds decentralized composting delivers outreach, landfill diversion and cost-saving benefits, with an estimated net benefit of about $100 per tonne, indicating the financial viability of a city-wide strategy to compost household food waste locally.

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.

Cosmos C. Alamanjo, Abimbola O. Adepoju, H. Martin, R.N. Baines · Zenodo (CERN European Organization for Nuclear Research) · Nigeria (Jos)

This mixed-methods study investigated farmers' perceptions, willingness, and capacity to use household sewage sludge as organic resources for peri-urban agriculture around Jos, Nigeria. Farmers were found to use a complex mix of fertilizers and were keen to utilize household sewage sludge for soil fertility, though constrained by accessibility. A critical finding was that household sewage sludge observed in the field is heterogeneous due to its proximity to urban refuse disposal, raising concerns for possible cross-contamination of pollutants and indicating a lack of extension guidance.

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.

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.

Gaston E. Small, Paliza Shrestha, Geneviève S. Metson, Katherine Polsky, Ivan Jimenez, Adam D. Kay · Environmental Research Communications · United States

Survey data from 142 gardeners and urban farmers in the Twin Cities Metropolitan Area, USA, characterized phosphorus (P) and nitrogen (N) inputs and harvest, and measured soil P concentrations at a subset of sites. Median application rates were 300 kg P/ha and 1400 kg N/ha, with low nutrient use efficiencies (2.5% for P, 5.0% for N). Garden soils had a median Bray P value of 80 ppm, far exceeding recommended levels, indicating a buildup and potential loss of P and N. Urban gardens, though only 0.1% of land area, constitute one of the largest inputs of P to the watershed.

Sally Brown, Ned Beecher · Compost Science & Utilization · United States

This study modeled the carbon benefits and costs of biosolids compost use in King County, Washington. Soil carbon sequestration was highest for use on disturbed soils, such as new housing developments, neglected urban soils, or highway right-of-ways (–1.1 Mg CO2eq per Mg compost), and lowest for use in well-tended yards or other highly maintained landscapes (–0.036 Mg CO2eq per Mg compost). Compost use for tree growth, calculated over a 30-year period, added above-ground sequestration benefits ranging from –1.53 Mg CO2eq per Mg compost for a mature tree grown on a healthy soil to –4.58 Mg CO2eq per Mg compost for a newly planted tree grown on a disturbed site. Assuming a 20 km haul distance, transport costs ranged from 0.005 Mg CO2eq per Mg compost for delivery in a 5 Mg truck to 0.09 Mg CO2eq per Mg compost for pick up in a personal vehicle.

Surendra K. Pradhan, Olufunke Cofie, Josiane Nikiema, Helvi Heinonen‐Tanski · Sustainability · Global

This research determined the fertilizer value of sawdust and fecal sludge (SDFS) pellets and compared their effect on lettuce cultivation with other fertilizers in a greenhouse and open field. SDFS pellets, with or without enrichments, resulted in higher saleable fresh weight lettuce yields than commercial compost, poultry manure, mineral fertilizer, or no fertilizer. Open field cultivation yielded more than greenhouse cultivation. While no helminth eggs were detected, some fecal coliforms were found in lettuces fertilized with almost all tested fertilizers, including NPK and the non-fertilized control.

Ignacio Laorga Fernández · · Global

This study analyzed the "risk reduction" effect of organic amendments from urban and agricultural waste (coffee grounds, domestic compost, livestock manure) on metal-contaminated soils. The method aimed to reduce the bioavailability of metals by increasing soil organic matter, enabling remediation for potential reuse as urban gardens. It was shown that immediate dilution and immobilization of contaminants occur, significantly reducing their mobility and absorption by edible plants.