Research & reports

Setha Low · · Global

This chapter examines environmental sustainability and the greening of public spaces in Paris and New York City, tracing the history and impact of interventions like community gardens, urban agriculture, and sustainable parks. These initiatives contribute to ecological sustainability by fostering stronger communities, supporting social reproduction, and promoting environmental justice. The study highlights how human ecological planning and ecosystem services assessments provide scientific strategies for enhancing sustainability in public space design.

Mary Ann N Daculog, Thea P Suaco, Romalyn D Parado · Advances in Agriculture Horticulture and Entomology · Philippines (Baguio City)

This study analyzed the chemical properties of soil in Barangay Lucnab, Baguio City, Philippines, focusing on macronutrient and micronutrient presence. Findings revealed low soil moisture content (27.26% to 33.60%) and strongly acidic pH levels (4.1 to 4.83). Organic matter content was also low (2.71% to 3.45%), suggesting that the soil's acidity may impact nutrient availability and solubility, thereby reducing harvest and productivity.

Scattareggia, Florent, Ancion, Nicolas, Jijakli, Haissam, Crutzen, Nathalie · Open Repository and Bibliography (University of Liège) · Global

This article discusses rooftop greenhouses (RTGs) as a potential solution to global land consumption and increasing food demand. RTGs utilize existing urban roof space, avoiding competition for land, and can form synergies with supporting buildings by using waste heat, CO2, urine, and rainwater, offering environmental benefits. Additionally, urban farming, including RTGs, can provide employment and educational opportunities in urban areas.

Kristiina Valter · Green Energy and Environmental Technology · Global

This paper describes productive blue-green roofs for stormwater management, highlighting features important for sustained environmental benefits. It explains that blue roofs use retention layers to delay or retain stormwater, and combining them with green roofs allows for growing edible crops, offering synergistic benefits. The paper presents case studies and testbeds of various blue and green roof sublayer combinations with edible and non-edible plants, considering design parameters and monitoring systems.

Anna Paltseva, Zhongqi Cheng, Murray B. McBride, Maha Deeb, Sara Perl Egendorf, Peter M. Groffman · Frontiers in Ecology and Evolution · Global

This synthesis paper summarizes current scientific knowledge on lead (Pb) contamination in urban garden soils and provides clear recommendations for assessing actual health risks and limiting exposure. Urban garden soils often contain elevated levels of Pb, mainly from legacy sources, which is a main barrier for urban gardening. Amendments are noted as unreliable for treating contaminated soils to reduce risk, as they do not always make contaminants less harmful.

Monika Egerer, Brenda B. Lin · CABI Reviews · Global

This review evaluated ecosystem services (ES) within urban agriculture (UA) systems and the trade-offs between these services. Urban agriculture provides many benefits and environmental services such as food provision, social cohesion, and climate regulation. However, it was shown that management decisions can create trade-offs between ecosystem services, where an increase in one service may potentially reduce the system's ability to provide another service at a desired level.

Nini Sané, Malick Mbengué, Amandine Laffite, Serge Stoll, John Poté, Philippe Le Coustumer · Water · Global

This study developed a wastewater treatment plant prototype coupled with Moringa oleifera seeds to reduce fecal indicator bacteria and antibiotic-resistant bacteria in domestic wastewater. The prototype alone reduced bacteria by 99.34%. The addition of Moringa oleifera seeds achieved high removal rates for E. coli (36.6–78.8%), fecal coliform (28.3–84.6%), Vibrio cholera (35.3–95.6%), and total flora (32.1–92.4%). For antibiotic-resistant bacteria, removal rates were up to 98% for E. coli and fecal coliform, 100% for Vibrio cholera, and 91.96% for total flora.

Byoung-Kwon Lee, Hyung-Kwon Yun, In-Kyoung Hong, Young-Bin Jung, Sangmi Lee, Sang-Deok Lee · Journal of people, plants, and environment · Global

This study investigated the effects of French marigold, zinnia, spearmint, and basil as companion plants at 10, 20, and 40 cm spacing on cherry tomato growth and fruit quality. Statistical differences were found in stem thickness and total number of fruits per plant, but not in plant height, total fresh weight of fruits, sugar content, fruit hardness, or vitamin C. Stem thickness decreased when spearmint and basil were planted at 20 cm or 40 cm compared to the control, and only zinnia at 40 cm increased the total number of fruits per plant.

Jiefu Wang, Yuepeng Sun, Kang Xia, Allison Deines, Ross Cooper, Karen Pallansch, Zhi‐Wu Wang · Water Environment Research · Global

This review examines the potential pivotal role of Urban Water Resource Reclamation Facilities (WRRFs) in sustainable urban agriculture. It highlights that reclaimed water can offer higher quality and less variable supply than other sources, while biosolids from wastewater treatment can be used as fertilizers or soil amendments. Additionally, WRRFs can produce renewable electricity, heat, CO2, and bioplastics, serving as essential resources for urban agriculture operations.

Nam-Gyeong Gim, Nam-gyeong Gim · The Jounal of Cultural Exchange · Cuba

This study explored strategic methods for effective school garden operation in elementary schools, focusing on Cuba's organopónico system. It conducted a PEST analysis of organopónico to extract technological strengths relevant to school garden education and a SWOT analysis of domestic elementary school gardens from an operational perspective. Findings suggest organopónico offers solutions for limited space through cantero farming and highlights organic farming using living organisms as a key method for strategic linkage in school gardens.

Uk-Hyeon Yeo, Sang‐Yeon Lee, Se‐Jun Park, Jun‐Gyu Kim, Jeong-Hwa Cho, Cristina Decano-Valentin, Rack-woo Kim, In-Bok Lee · Agriculture · Global

This study analyzed the energy-saving efficiency of Building-integrated Rooftop Greenhouses (BiRTGs) for urban agriculture using building energy simulations (BES) combined with computational fluid dynamics (CFD). For growing tomatoes, the annual energy load in a BiRTG was 464,673 MJ, representing an average 5.2% reduction compared to a single-span greenhouse (490,128 MJ). Energy savings were observed from October to April due to heat transfer from the building, and implementing alternating air temperature management (ATM) from November to March further reduced heating energy loads, yielding average energy savings of 11.8%.

Eleano Rodrigues da Silva, Sônia Sena Alfaia, Marta Iria da Costa Ayres, S. G. A. de Sousa, Robert Corrêa Rodrigues · Concilium · Global

This study investigated the production of liquid humus (HL) using different solvents and proportions for use in urban and peri-urban afforestation and agriculture. Nutrient content and concentrations, yields, and the odor and appearance of the residue were analyzed. Results indicated that the odor in all HL samples was very mild, practically odorless, allowing their use in urban areas. From the chemical compositions of the analyzed products, it was inferred that HL has potential for use in urban agricultural practices, possibly contributing to improving soil cation exchange capacity (CTC).

José Hilario Rocha Araujo, A. Pando-Bahuon, C. Hartmann, H. Aroui-Boukbida, Thierry Desjardins, Thomas Z. Lerch · Frontiers in Ecology and Evolution · Global

This study evaluated the possibility of growing green vegetables on soils made from excavated deep horizon soils and green waste compost. Over three seasons, the effects of different amounts of compost (10, 20, and 30%) and the addition of earthworms (Lumbricus terrestris) on the production of lettuce, arugula, and spinach were tested in situ. The results demonstrated that it is possible to reuse urban mineral and organic wastes to engineer soils adapted to agriculture. Higher doses of compost significantly increased plant biomass, especially when earthworms were introduced.

· Middle East Journal of Agriculture Research · Egypt

Two experiments were conducted in 2020 and 2021 on a rooftop garden in Giza, Egypt, to investigate the effect of substrate type and fertilizing programs on molokhia and spinach yield and nitrate content. Substrate S1 (50% perlite: 50% peat moss) was found more suitable for high yield. While chemical nutrient solution (CNS) alone resulted in the highest yield, the combination of S1 and CNS followed by compost tea for 5 days before harvest (CNS+5) was most suitable for high yield with lower nitrate accumulation.

Jerome Wei Chiang Teng, Chew Beng Soh, Shiddalingeshwar Channabasappa Devihosur, Ryan Hong Soon Tay, Steve Kardinal Jusuf · Sustainability · Global

This study investigated the effects of agrivoltaic systems on rooftop microclimates and PV efficiency. ENVI-met simulations showed that PV temperatures in plots with crops below the PV system were 2.83 °C lower on sunny days and 0.71 °C lower on cloudy days, leading to a 1.13–1.42% and 0.28–0.35% improvement in PV efficiency, respectively. Data from a physical prototype indicated that evaporative cooling reduced ambient temperatures, with the agrivoltaic system generating 3.05–3.2% more energy daily compared to a control without crops.

Petra Schneider, Tino Fauk · · Global

A study based on a literature review and field survey conducted from 2017 to 2020 in Ecuador, Germany, Sweden, Uganda, and Vietnam, examined the role of allotment gardens (AGs) in connecting nature and people. Allotment gardens provide substantial urban ecosystem services, contribute to habitat connectivity, and significantly impact human health. Beyond food production and recreation, they offer crucial benefits for public health, wellbeing, social inclusion, the environment, and serve as cultural archives, with their intrinsic purpose being connectivity for habitats, people, ecosystem services, and circular flux management.

José Luis Villalpando, Daniel Francisco Chi-Maas, Itzel López‐Rosas, Víctor Ángel Aquino-Luna, Jesús Arreola-Enríquez, Julia Cristel Alcudia-Pérez, Gilberto Matos-Pech, Roberto Carlos Gómez-García, Jesús Froylán Martínez-Puc, William Cetzal‐Ix · Agriculture · Global

This study evaluated a backyard system using 50cm × 50cm pinewood boxes for maize and peanut over nine months. Approximately 213 kg of organic residues were converted into 300 kg of mature compost, and plant development was compared between compost and control conditions. Correlation analyses of morphological properties showed that nutrient effects were positively associated with crop morphology, with maize yields of 9 kg/m2 in compost conditions and 6.6 kg/m2 in control, and peanut yields of 184 g/m2 in compost and 73 g/m2 in control.

Blessing Chidinma Nwachukwu, Olubukola Oluranti Babalola · Frontiers in Sustainable Food Systems · Global

This review explores metagenomic techniques for studying plant root-associated microbiota and microbial ecology, highlighting their role in understanding and improving crop yields in rural and urban agriculture. Metagenomics, a non-culture approach, enables the identification of unculturable microorganisms and their functional traits. A detailed understanding of these organisms and their interactions can facilitate improved plant growth and sustainable crop production.

Paulien C. H. van de Vlasakker, Karin Tonderski, Geneviève S. Metson · Frontiers in Sustainable Food Systems · Global

A review of empirical peer-reviewed studies (2000-2021) on nutrient losses to water from soil- and ground-based urban agriculture. Of 241 publications screened for a stated concern with nutrient losses to water, 20 were retained, but only seven had actually measured losses to water. Of four experimental studies, three measured leachate losses under different garden management practices; of 16 real-world studies, only four quantified losses to water as leachate, with measured average losses ranging from 0.005 to 6.5 kg/ha for phosphorus and 0.05 to 140 kg/ha for nitrogen. Thirteen of the 16 non-experimental studies provided input and harvested-crop data allowing nutrient balances to be calculated; despite wide value ranges, most studied gardens showed nutrient surpluses (inputs exceeding crop harvest) for nitrogen and phosphorus but not potassium, identified as a risk factor for losses to water, though large surpluses were not always linked to higher leachate losses. The review concludes that more field studies measuring actual losses to water, and documenting contextual factors, are needed to determine whether urban agriculture can contribute to a circular economy without causing nutrient-related water quality impairment.

Mamdouh M. Arafa Arafa, Sabry M. Shaheen, A.M.K Mansour, M. F. A. Ahmed · International journal of Environmental Studies and Researches · Egypt

Over the 2020 and 2021 growing seasons at Sadat City farms (Cairo–Alexandria Desert Road, Menoufia Governorate, Egypt), this study tested the effect of compost application on root-rot disease management and tomato productivity. Rhizoctonia solani and Sclerotium rolfsii were isolated from rotted tomato plants as the main pathogens causing root rot and damping-off, which reduced yield. Adding plant residue, cow manure, or compost (plant residue plus cow manure) to soil before transplanting, at a rate of 1.2 kg/m², significantly reduced disease incidence and raised plant survival compared with untreated controls in both seasons. Compost — a tomato-rich organic fertilizer — applied at 1.2 kg/m² produced the largest reduction in disease incidence and the largest increases in vegetative growth (plant height, branches per plant, leaves per branch), yield parameters, flavonoid content, and total phenol content across both seasons; no clear significant differences were found between the plant-residue and cow-manure treatments in plant growth characteristics.

Eric J. Chapman, Gaston E. Small, Paliza Shrestha · Urban Ecosystems · Global

A study quantifying leachate and soil moisture from experimental urban garden plots receiving various soil amendments — high and low levels of manure and municipal compost, synthetic fertilizer, and no inputs — over three years. A simple mass-balance hydrologic model was parameterized for high-input municipal-compost and no-compost garden plots plus reference turfgrass plots, and run over three growing seasons under ambient precipitation and three elevated-precipitation scenarios. Soil moisture varied across treatments, with the highest mean levels in manure-compost plots and the lowest in synthetic-fertilizer plots. Soil amendment treatments explained little of the variation in weekly leachate volume, but high municipal compost and synthetic fertilizer had the lowest leachate volumes, while high and low manure compost had slightly higher volumes. Garden plots received 12-16% greater total water inputs than turfgrass plots due to irrigation, but total leachate was 20-30% lower for garden plots across climate scenarios because evapotranspiration was 50-60% higher in garden plots. Differences between high-municipal-compost and no-compost garden plots were small relative to the difference between garden plots and turfgrass overall. The study concludes that garden soil amendments influence water retention, and that the higher water retention, infiltration, and evapotranspiration potential of garden soils relative to turfgrass indicate hydrologic ecosystem services may be an underappreciated benefit of urban gardens.

Kyle Richardville, Dan Egel, Andrew Flachs, Amit K. Jaiswal, D.J. Perkins, A. W. Thompson, Lori Hoagland · Urban Agriculture & Regional Food Systems · Global

A two-year field trial tested whether amending degraded urban soils with locally made leaf-mold compost could improve soil chemical and biological properties and support the survival of a plant-growth-promoting, disease-suppressive microbial inoculant (Trichoderma harzianum T-22) in tomato (Solanum lycopersicum) production. Compost-amended plots showed markedly higher active soil organic matter and marketable fruit yield in both years, lower foliar disease severity in year two, and reduced transplant-stress deaths from T-22 inoculation in one cultivar, but the authors caution that all composts must be tested for heavy metals or pathogens and that overapplication can reduce crop health.

Jennifer Paola Borja Llivigañay, Karla Maribel Rocano Bustamante · Universidad Politécnica Salesiana Repositorio Digital (Universidad Politécnica Salesiana) · Global

A student thesis project (Universidad Politécnica Salesiana repository, Ecuador, 2022) by students of the Unidad Educativa Agronómico Salesiano in Paute canton, Azuay province, evaluated the capture, reproduction, and application of the antagonist fungus Trichoderma spp. as a biological control agent against soil fungal pathogens (Phytophthora, Rhizoctonia, Sclerotium, Pythium, Fusarium). Using cooked-rice traps placed in soil holes to capture the fungus, and preparing a liquid formulation from it, the project analyzed the protective benefit against parasitic fungi in lettuce crops between November 2021 and May 2022.

Brunno da Silva Cerozi, Caitlin G. Arlotta, Matthew L. Richardson · Agriculture · Global

A study (2022, Agriculture) examined integrating urban agriculture with aquaculture to reduce water use and cost, competition for water, chemical fertilizer use, and the environmental impact of discharging nutrient-rich agricultural water into fresh and saltwater bodies, noting that urban aquaculture could also directly benefit human health as a local source of lean protein, while few studies had demonstrated the practical feasibility and production advantages of using aquaculture wastewater to fertigate specialty crops in cities. Four spring crops (bok choy, tatsoi, radish, turnip) and two fall crops (pole beans, sugar snap peas) were grown using nutrient-rich fish aquaculture effluent versus well or municipal water to evaluate effects on soil fertility and crop production. The fish effluent raised soil pH and potassium and increased pole bean count by 9.1% (bean mass trended toward significance but was not conclusive); the soils used were relatively nutrient-rich even before the effluent was applied, which may explain the limited impact, and the study suggests differences could be more pronounced in acidic, nutrient-poor soils or with longer-duration fertigation.

M.C.G. Haitsma Mulier, F.H.M. Van de Ven, Paul Kirshen · Energy Nexus · Global

Drawing on case-study water-energy-food (WEF) nexus research at urban farms, which found that two distinct types of "food" are relevant to urban agriculture, this study (2022, no specific region) splits the "food" component of the WEF framework to build a water-energy-nutrients-food (WENF) nexus framework for urban farming. The systematic WENF monitoring, analysis, and evaluation framework aims to support quality data acquisition during case-study research at farm sites, addressing a quantitative data gap on urban agriculture and closed circularity loops; it differentiates stocks of water, energy, nutrients, and food, describes flows within each, and identifies multi-sectoral flows and interdependencies among the four resource stocks to formulate options for circularity in urban farming. The analysis indicates urban systems offer many opportunities for realizing sustainable agriculture in cities because waste management and farming can mutually reinforce each other: local reuse of resources found in urban "waste" could reduce stormwater problems and energy needs for water, nutrient, and food transport, irrigation, and wastewater pumping, while eliminating the need for synthetic soil amendments and unsustainable mineral mining, and reusing resources from urban (waste)water in urban farming could reduce food production's overall negative environmental impact.