Research & reports

Solomon Tulu Tadesse, O. Oenema, Christy van Beek, Fikre Lemessa Ocho · Nutrient Cycling in Agroecosystems · Ethiopia

This study investigated the diversity and nutrient balances of urban and peri-urban agriculture (UPA) systems in three Ethiopian cities, using data from 425 households (Addis Ababa: 175, Adama: 126, Jimma: 124). It identified six farm types, including commercial livestock (cLS) and subsistence field crop (sFC) systems. The study found that cLS systems accumulated significant nutrients (450 kg N, 85 kg P, 260 kg K ha−1 year−1) with low use efficiency (26% N and P, 15% K), while sFC systems depleted nutrients (−30 kg N, −17 kg K ha−1 year−1) with high use efficiency.

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.

P.S. Bouda, Edmond Hien, A. Dioma, Hyacinthe Kambiré, Yacouba Maïga, Der Adolphe Somé, Sylvie Nazaret, A.S. Ouattara · DOAJ (DOAJ: Directory of Open Access Journals) · Burkina Faso

A study in Ouagadougou sub-urban agricultural fields, Burkina Faso, assessed the impact of using untreated Solid Urban Wastes (SUW) as agricultural fertilizers on soil properties and crop production. SUW amendment significantly increased pH, total C, N, P, and available P, and maize height and biomass yield were 124% and 164% higher in amended plots, respectively. However, trace metal elements (Cu, Zn, Pb, Ni, Cr) concentrations were higher in amended fields, indicating that urban waste carries contaminants posing public health risks.

Angelina Moreira Melo, Daniel Calbino, Yuri Gomes Figueiredo, Fabiola Paulino da Silva, E. R. de O. Carvalho · Cadernos de Agroecologia · Brazil

This empirical work, based on participatory research, analyzed the social relations between producers of the Vapabucu community garden in Sete Lagoas, Brazil, and municipal public support organs. Research results indicate that while agroecological knowledge has advanced significantly in the technical dimension of agronomic production, the social relations among producers still show contradictions inherent to agroecological assumptions.

Cécile Le Guern, Liliane Jean‐Soro, Béatrice Bechet, Thierry Lebeau, Dorine Bouquet · Land Degradation and Development · France

Urban allotment gardens in Nantes, France, were found to have soil contamination, with lead (Pb) levels ranging from 100–400 mg kg−1, posing health risks. Local actors collaborated to characterize soil, evaluate sanitary risks, and discuss management options. The most frequent solution was replacing polluted soils with clean soils, while other strategies included on-site management of excavated soil, non-accumulative cropping, or changing land use.

Désiré Jean‐Pascal Lompo, Emmanuel Compaoré, Michel Papaoba Sédogo, Martina Melapie, Charles Bielders, Eva Schlecht, Andreas Buerkert · Nutrient Cycling in Agroecosystems · Burkina Faso (Bobo Dioulasso)

This study investigated nutrient management in six urban vegetable gardens in Bobo Dioulasso, Burkina Faso, quantifying nitrogen (N), potassium (K), and carbon (C) fluxes and balances. Inputs of N and K significantly exceeded recommended amounts, leading to substantial horizontal annual surpluses of 1013 kg N ha−1, 879 kg K ha−1, and 25 t C ha−1. While total balances for N and K were positive, the total balance for C was negative, indicating an environmental tradeoff due to excessive nutrient input.

John Misenheimer, Clay Nelson, Evelyn Huertas, Myriam Medina-Vera, Alex Prevatte, Karen D. Bradham · Geosciences · Puerto Rico

Total and bioaccessible arsenic (As) and lead (Pb) levels, and their uptake by 10 commonly grown garden plants, were examined in three urban community gardens in Puerto Rico. Total As ranged from 2 to 55 mg/kg and Pb from 19 to 172 mg/kg in soils. Leaves accumulated higher concentrations of As and Pb than edible flesh, with culantro leaves showing the highest concentrations (3.2 mg/kg dw As, 8.9 mg/kg dw Pb).

D.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.

Miguel A. Altieri, Clara I. Nicholls · Agro Sur · Global

Although urban agriculture (UA) is estimated to provide 15-20% of global food, its significant contribution to city food self-sufficiency is questionable due to low yields in most existing urban farms. Agroecology can enhance UA's productive potential by offering key principles for designing diversified, productive, and resilient urban farms. This paper describes principles and practices for increasing soil quality and enhancing plant health.

M. L. Dotaniya, V. D. Meena, S. Rajendiran, M. Vassanda Coumar, Asha Sahu, J. K. Saha, S. Kundu, Hiranmoy Das, A. K. Patra · Journal of the Indian Society of Soil Science · India (Bhopal)

A case study in peri-urban agricultural lands near Patranala, Bhopal, India, investigated the impact of over 50 years of untreated sewage water irrigation on soil properties. Findings showed higher concentrations of heavy metals in surface soils of sewage-irrigated fields, posing a major concern. Conversely, soil microbial population, enzymatic activities, and organic carbon content were also higher, indicating enhanced carbon sequestration.

Melinda R.S. Moata, Oskar Kollo, Yofris Puay, Yos Rhuma, Charles Tlonaen, Zakharias Duka · PARTNER · Indonesia (Kupang)

This survey evaluated 10,078 hectares of unmanaged land in Lasiana, Kupang city, Indonesia, to assess its capability for urban agriculture. The study found that two land units were classified as Class III land capability due to limiting factors such as soil depth, erosion level, soil fertility, drainage, and stoniness. Recommendations for land management included increasing soil depth and applying urban forest or urban farming development with multifunctional land uses.

Monika Egerer, Alessandro Ossola, Brenda B. Lin · BioScience · United States (California central coast)

This study conceptualizes community garden soils within the novel ecosystem framework, arguing that gardeners cultivate novel agroecosystems from their garden beds' soil. On the California central coast, community garden soils may not be influenced by land-use legacies associated with geographic location. Instead, intensive soil reworking by gardeners can wash out legacy signals and decadal chronological trends, leading to soil homogenization that reduces biophysical ties to the underlying earth.

이윤숙 · · Global

Urban agriculture has gained emphasis due to its importance for leisure and recreation in modern society. However, public health may not be guaranteed due to continuous odors from animal compost. Biochar is an amendment that can reduce odors and enhance crop productivity, but this abstract is truncated and does not present specific research findings.

Volker 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.

Eileen Bogweh Nchanji, Imogen Bellwood‐Howard, Nikolaus Schareika, Takemore Chagomoka, Johannes Schlesinger, D. Rodríguez Torres Axel, Glaser Rüdiger · International Journal of Agricultural Sustainability · Ghana (Tamale)

An ethnographic study in Tamale, Northern Ghana, assessed the sustainability of urban vegetable production between 2008 and 2014. While urbanization increased cultivation of profitable vegetables like cabbage, the practice involved irrigation with grey and wastewater and high pesticide use, posing health and environmental hazards. Industrial growth reduced open space urban agriculture by 8.7%, leading farmers to use interstitial spaces and peri-urban fringes, indicating a dynamic but not yet sustainable production system.

Marta Bożym · Ochrona Środowiska i Zasobów Naturalnych · Poland

A study measuring heavy-metal content (cadmium, lead, copper, zinc, nickel, chromium) in compost and resident earthworms sampled from home composters and allotment gardens in the Opole region of Poland. The compost samples themselves were not contaminated with heavy metals and stayed within Polish legal limits for solid organic fertilizers. However, metal accumulation in earthworms varied by metal: the bioaccumulation factor (BAF) was high for cadmium, lead and zinc, while no accumulation was found for nickel, chromium or copper. The authors conclude that earthworm species native to Poland, such as Eisenia fetida, can serve as potential bioindicators of metals in the environment.

Elizabeth A. Miernicki · Illinois Digital Environment for Access to Learning and Scholarship (University of Illinois at Urbana-Champaign) · United States

A study from the University of Illinois at Urbana-Champaign, USA, that identifies soil contamination as a universal concern in urban agriculture and notes that the long-term benefits of alternative soil management systems such as raised beds have not been explored in the scientific literature. Its stated objective is to determine the effects of six soil management options - direct soil with synthetic fertilizer (DSF), direct soil with organic amendments (DSO), raised-bed mixture with synthetic fertilizer (RBMF), raised-bed mixture with organic amendments (RBMO), raised-bed compost-only with synthetic fertilizer (RBCF), and raised-bed compost-only with organic amendments (RBCO) - on yield of kale, garlic, pepper, cilantro and radish, on soil biological, chemical and physical properties, and on ecosystem services such as water and nutrient retention. Data collected include marketable versus cull yield, soil nutrients and organic matter, soil moisture, weed emergence, infiltration rate and bulk density, but this abstract does not report the comparative results themselves.

Runrid Fox-Kämper · · Global

This book provides insights and examples of how urban space is negotiated, describing urban gardens as "lived places" where social relations, meanings, and a sense of place are developed. To trigger social benefits, it is essential that these sites fulfill more functions than just food growing and leisure. Horticultural practices, such as using pesticides or fertilizers, have a strong influence on the ecological impact of urban gardening; although awareness among gardeners has increased due to training programs in recent decades, this impact persists.

S. A. Materechera · Journal of Soils and Sediments · South Africa (Mahikeng)

Properties of subsoil in soils used for urban and peri-urban agriculture in Mahikeng city, South Africa, were investigated. Measurements of physical, chemical, and biological properties in four soil profiles (topsoil 0-20cm, subsoil 20-40cm) revealed high bulk density (mean 2.06 Mg m−3) and high penetrometer resistance (1.89 MPa) in the subsoil, indicating potential impedance to root growth. Low hydraulic conductivities at saturation and low plant-available boron levels were also found, leading to the conclusion that subsoil constraints to root growth are widespread in these soils.

Godswill Azinwie Asongwe, Bernard Palmer Kfuban Yerima · Greener Journal of Soil Science and Plant Nutrition · Cameroon (Bamenda)

This study analyzed heavy metal levels (chromium, manganese, lead, cadmium) in 21 urban and peri-urban agricultural wetland soil samples in Bamenda municipality, Cameroon. Average concentrations were 35.73 mg/kg for chromium, 0.08 mg/kg for manganese, 30.64 mg/kg for lead, and 0.45 mg/kg for cadmium. These concentrations were generally lower than the maximum WHO permissible levels.

Christiane Joi Allen · Libraries and Cultural Resources (University of Calgary) · India (Mumbai)

This study evaluated the environmental, social, and economic benefits of urban agriculture in Mumbai, India, using Life Cycle Assessment and Cost Benefit Analysis. Results indicate that urban agriculture has lower greenhouse gas emissions, energy consumption, and water consumption but higher eutrophication potential compared to commercial large-scale agriculture.

Araceli Calderón Cisneros · Dialnet (Universidad de la Rioja) · Mexico (Chiapas)

This qualitative study analyzed the role of family urban agriculture in urban sustainability in San Cristobal de Las Casas, Chiapas, Mexico, using open and structured interviews. The visited agricultural systems showed characteristics favoring resilience and sustainability, such as low use of external inputs and recycling of domestic waste. However, a limitation found was that the contribution of own production to family consumption is very low, despite existing food, environmental, and socio-cultural motivations for its continuity.

Hardiyanto Hardiyanto, Constancio C. de Guzman · Indonesian Journal of Agricultural Science · Philippines (Metro Manila)

This study investigated the levels and distribution of lead (Pb) and cadmium (Cd) in white cabbage, soil, and irrigation water from urban agricultural sites in Las Piñas and Parañaque, Metro Manila, Philippines. Field areas were divided into three sections based on distance from the main road (0, 25, and 50 m), and metal contents were measured by Atomic Absorption Spectrophotometry. The average Pb content (1.09 µg g-1 dry weight) in white cabbage was highest immediately beside the main road, with a similar trend in soil. A negative relationship was found between distance from the main road and Pb and Cd contents in white cabbage and soil. While overall concentrations of Pb and Cd in white cabbage, soil, and irrigation water were within acceptable limits, further study on heavy metal contamination in crops, especially those grown along main roads, was suggested.

Kafeel Ahmad, Zafar Iqbal Khan, Asma Ashfaq, Ameer Khan, Hazoor Ahmad Shad, Mujahid Sher, Zahoor-ul-Hassan Dogar, Ijaz Rasool Noorka, Sumaira Yasmin, Vincenzo Tufarelli, Eugenio Cazzato · The Philippine Agricultural Scientist · Pakistan

This study analyzed heavy metal and metalloid levels in soil and cabbage (Brassica oleracea) from two urban farming sites in Sargodha, Pakistan, irrigated with wastewater. Findings showed that mean concentrations of arsenic (As) and cadmium (Cd) in soil, and manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo), cadmium (Cd), and lead (Pb) in cabbage, exceeded permissible limits at both sites. Significant differences were observed in metal and metalloid levels in vegetable samples between sites.

Mujtaba Baqar, Nadia Jamil, Naveed Ahsan, Kiran Khanum, Abdul Qadir, Mariyam Zameer, Anam Khalid · Transylvanian Review · Pakistan (Lahore)

This case study investigated the impacts of heavy metals from wastewater irrigation on soil, groundwater, and leafy vegetables (Indian mustard, spinach, fodder) in the Charrar Drain catchment, Lahore, Pakistan. Samples were collected from seven sites. Drain water showed Cd, Cr, and Pb concentrations exceeding limits at most sites, and groundwater Cd concentrations also exceeded limits, though Cr and Pb were within permissible ranges. Soil samples contained Cd, Cr, and Pb, and leafy vegetables irrigated with wastewater showed varying heavy metal concentrations, indicating a heavy metal bioaccumulation issue that may exceed threshold limits.