Research & reports
Peer-reviewed research and reports on community urban agriculture, food education, composting, welfare and more.
Theme
Critical findings
11 results
Applying recovered nutrients and pruning waste to enrich and regenerate agricultural soils in urban agriculture: Effects on emissions and yield of spinach and sweet potato
2026Guido Evangelista, Juan David Arosemena, Gaia Stringari, Joan Romanyà, Xavier Gabarrell, Francesco Orsini, Gara Villalba · Agriculture Ecosystems & Environment · Global
This study evaluated the application of 150 t ha-1 of ramial chipped wood (RCW) to degraded peri-urban agricultural soils, comparing its effects on yield, soil health, and greenhouse gas emissions for spinach and sweet potato. Spinach grown with RCW showed the lowest productivity (1.16 – 0.32 kg m-2) among treatments, while sweet potato achieved the highest yield (1.72 – 1.99 kg m-2). High RCW doses initially led to higher CO2 emissions but significantly reduced N2O emissions for spinach (from 0.36 kg ha-1 to 0.07 kg ha-1) and enhanced soil organic carbon and nitrogen stocks for sweet potato, indicating agronomic and environmental trade-offs.
Environmental trade-offsOrganic cycleCompostClimate changePeri-urban agricultureImpact of waste from the municipal slaughterhouse in Nkongsamba on plant diversity (Littoral-Cameroon)
2025Yanick Borel Kamga Valerie Njitat Tsama* · Journal of Biodiversity and Environmental Sciences (JBES) · Cameroon (Nkongsamba)
This study assessed the impact of untreated waste from the municipal slaughterhouse in Nkongsamba, Cameroon, on vegetation by conducting floristic inventories at upstream, near, and downstream sites. Twenty-five 100 m2 plots were established at each site, revealing a total of 105 species from 79 genera and 41 families. The downstream site exhibited the highest species richness with 81 species, 70 genera, and 35 families, but these results showed a dominance of ruderal taxa and pollution bio-indicators like Commelina benghalensis and Tithonia diversifolia, reflecting ecological disturbance of the plant environment.
Environmental trade-offsCompostOrganic cycleUrban–rural linkageEXPLORING THE RECYCLING OF MANURE FROM URBAN LIVESTOCK FARMS: A CASE STUDY IN ETHIOPIA
2021Solomon Tulu Tadesse, O. Oenema, Christy van Beek, Fikre Lemessa Ocho · Frontiers of Agricultural Science and Engineering · Ethiopia
This study in Jimma, Ethiopia, from 2015-2050, used an N mass flow model and field experiments to explore manure recycling from urban livestock farms under four scenarios. It found that livestock manures are the main organic wastes in urban areas, and manure production in urban and peri-urban agriculture (UPA) is projected to increase 3 to 10 times. Critically, only 13% to 38% of manure nitrogen will be recycled in croplands, and intensification of urban livestock production greatly increased nitrogen surpluses, indicating a significant environmental tradeoff.
Environmental trade-offsOrganic cyclePeri-urban agricultureFood sovereignty & justiceCompostMeasuring the Fate of Compost-Derived Phosphorus in Native Soil below Urban Gardens
2019Gaston 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.
Environmental trade-offsCompostOrganic cycleExcess phosphorus from compost applications in urban gardens creates potential pollution hotspots
2019Gaston 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.
Environmental trade-offsCompostOrganic cycleClimate changeThe fate of compost-derived phosphorus in urban gardens
2018Gaston 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.
Environmental trade-offsCompostOrganic cycleUrban–rural linkageThe monitoring of soils on the land areas as information support for the register of soil resources at the local level
2018D.V. Belobrova, Д. А. Шаповалов · Dokuchaev Soil Bulletin · Russia
This study conducted large-scale (1:5000) soil mapping of garden non-commercial partnerships in the Meshchera lowland of Noginsk district, Moscow region. Investigations revealed that initial soils underwent significant transformation since their creation, with soddy podzolic and boggy soils changing into agro-soddy podzolic soils and agrozems due to intensive development and fertilizer use. While these changes reflect increased productivity and quality of allotment soils, the transformed soils are characterized by neutral pH and high/medium mobile phosphorus content, but are poor in exchangeable potassium compared to natural soil profiles.
Environmental trade-offsOrganic cycleCompostCommunityEffects of biochar, waste water irrigation and fertilization on soil properties in West African urban agriculture
2017Volker Häring, Delphine Manka’abusi, Edmund Kyei Akoto-Danso, Steffen Werner, Kofi Atiah, Christoph Steiner, Désiré Jean‐Pascal Lompo, S.G.K. Adiku, Andreas Buerkert, Bernd Marschner · Scientific Reports · Sub-Saharan Africa
This 2-year study in Tamale (Ghana) and Ouagadougou (Burkina Faso) investigated the effects of biochar, wastewater irrigation, and fertilization on sandy, nutrient-depleted soils in urban vegetable production. Biochar addition (2 kg m⁻²) initially doubled soil organic carbon (SOC) stocks, but 35% SOC losses occurred afterward. Both biochar types had no effect on soil pH, phosphorus availability, or cation exchange capacity, though rice husk biochar retained nitrogen. The study found that the effects of biochar and waste water were less pronounced than reported elsewhere.
Environmental trade-offsOrganic cycleCompostClimate changeUrban food systems
2015J.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.
Environmental trade-offsOrganic cycleCompostFood lossHealthAgriculture urbaine et valorisation des déchets au Bénin : une approche de développement durable
2010Hygin Faust Kakai, Alban Gilles Kakai, Armelle Grey Tohouegnon · VertigO · Benin (Cotonou)
This study in Benin examined urban agriculture and waste valorization in Cotonou, Abomey, and Abomey-Calavi. In Cotonou, overexploitation of sandy, organic-poor soil in market gardening led to soil impoverishment, forcing gardeners to use chemical fertilizers with negative environmental impacts. However, some market gardeners adopted compost use, transitioning to organized organic urban agriculture after a waste management project supported waste valorization. This dynamic was not observed in Abomey, where urban agriculture is practiced in family spaces and public areas, unlike Cotonou's developed sites. Abomey-Calavi, despite rapid demographic growth, was almost devoid of urban agriculture practices.
Environmental trade-offsOrganic cycleCompostEconomicsHealthEnvironmental concerns of urban and peri-urban agriculture: case studies from Accra and Kumasi.
2001E. Mensah, Philip Amoah, Pay Drechsel, Robert Clement Abaidoo · CABI Publishing eBooks · Sub-Saharan Africa
This work, presented as case studies from Accra and Kumasi, addresses environmental concerns of urban and peri-urban agriculture. It focuses on waste composting for urban and peri-urban agriculture, aiming to close the rural-urban nutrient cycle in Sub-Saharan Africa.
Environmental trade-offsPeri-urban agricultureCompostOrganic cycle