Research & reports

Isabela Thomas Mkude · TANZANIA JOURNAL OF SCIENCE AND TECHNOLOGY · Tanzania (Dar es Salaam)

In Dar es Salaam, Tanzania, the utilization of faecal sludge derived compost (FSDC) by urban farmers remains limited due to farmers' prejudice and hesitance. This study investigated factors influencing FSDC acceptance through a cross-sectional survey of 76 urban farmers. Results indicated that garden location in communal areas, income generation as the primary farming purpose, and accessibility of soil inputs were significantly associated with FSDC acceptance. Farmers' awareness and experience also played important roles.

Gök A., Arıkan M. · Journal of Environmental Science and Health, Part B · Türkiye (Istanbul)

Tracks how DDT, a legacy contaminant, restructures the soil microbiome of an urban garden in Istanbul across a 15-day microcosm experiment. Rather than broad diversity loss, Shannon diversity rose steadily as sensitive taxa were suppressed; Rhodococcus, Kribbella and Nitrospira increased while Pedomicrobium and Lysobacter declined. Inferred functions shifted away from aromatic amino-acid and fatty-acid metabolism and towards degradation of chlorinated aromatics, redox homeostasis and stress response — a successional move to a stress-resilient, potentially degradative community.

Santanu Maiti, 2S. Aanand, 3Rajalakshmi Kalaivanan, 4V. Mahendra Varman, · Zenodo (CERN European Organization for Nuclear Research) · Global

A technical guide describing wicking bed aquaponics, a resource-efficient, home-scale food production system that combines aquaculture with soilless plant cultivation. Fish waste is biologically converted into nutrients for plants, while the wicking bed functions as a sub-irrigation unit that uses capillary action to move water from a reservoir to the plant root zone, providing consistent moisture while minimizing evaporation loss.

Phạm Trung Kiên, Liliane Jean-Soro, Huong Le Thi Thu, Bernard De-Gouvello, Béatrice Bechet · Earth Environmental Sustainability · Global

Arguing that existing "Water-Energy-Food" nexus thinking fails to capture the complexity of urban nature-based solutions such as urban gardens, this perspective paper proposes a "Food-Water-Soil (FWS) nexus" framework analyzed through the dual lens of ecosystem services (ES) and ecosystem disservices (EDS), which arise together with ES rather than as mere byproducts. It positions ES and EDS as the core mediating functions that define a system's potential and limits, and conceptualizes soil as a "living infrastructure" whose management-driven dynamic properties govern the trade-offs and synergies between food production and water dynamics.

Eduardo Antonio CastroNemocon · Institutional Repository of the National University Open and Distance UNAD (Universidad Nacional Abierta y a Distancia) · Colombia (Bogotá)

Focused on the UPZ 96 Lourdes area of the Santa Fe Tercera locality in Bogota, Colombia, this paper reports on an initiative that treats urban agriculture as a tool for building sustainable food systems. From an environmental standpoint, it advances a process of training and knowledge exchange using an agroecological approach in private spaces, generating self-supply and self-consumption of agricultural products and using household spaces to plant and harvest organic food free of fungicides that compromise food safety, aiming to prevent declines in quality of life and health problems for consumers. Drawing on a political ecology perspective, the initiative seeks policy directions and direct social action to improve the quality of food consumed in daily diets, prioritizing responsible environmental management and the practice and production of organic agricultural food in urban spaces — promoting healthy eating habits while culturally preserving knowledge exchange and ancestral planting, harvesting and consumption practices in a country whose historical character has been agricultural, and aiming to guarantee food sovereignty.

Xiaoya Lin, Jiajun Xu, Ting Wang, Randy A. Dahlgren, Lanyue Feng, Wenli Qin, Qinglong Liang, Zhixia Qin, Zengling Ma, Liyin Qu · Environmental Technology & Innovation · Global

A two-year monthly investigation of water quality and dissolved organic matter (DOM) optical properties (absorbance and fluorescence) in a eutrophic, urban-agricultural wetland. Dissolved organic carbon (DOC) increased from spring to summer in both years and correlated significantly with trophic level index (TLI), total nitrogen, COD, and chlorophyll a, indicating that eutrophication added to the organic carbon pool through both sewage inputs and algal production. Loss of protein-like component C3, together with a significant negative correlation between microbial humic-like component C2 and dissolved oxygen, suggested that microbial deoxygenation converted bio-labile DOM into recalcitrant DOM (RDOM) during summer. In winter, lower temperatures limited microbial transformation, and continuous sewage inputs increased protein-like C3, while RDOM removal via particle adsorption-sedimentation and photodegradation exceeded its accumulation. Machine learning analysis found microbial transformation explained 39.1-41.2% of variation in humic-like components, more than terrestrial inputs, sewage sources, and algal production combined (2.1-31.6%), identifying microbial transformation as the dominant driver of wetland RDOM formation. Eutrophication is stated to have negative effects on wetland ecosystems, though the study also notes that, if sewage and algae are effectively managed, the same process could enhance carbon sequestration.

Neha Toppo, Shashi Kumar Sah, Vipin Chandra Mishra · Zenodo (CERN European Organization for Nuclear Research) · Global

This chapter introduces the concept of urban soils, describing how urbanization disturbs, compacts, contaminates, and mixes natural soil horizons with construction debris, bricks, asphalt, metals, and plastics, altering their structure, fertility, and contamination levels compared with agricultural or natural soils. The excerpted text is introductory background on urban soil formation and ecosystem functions rather than a report of original site data, measurements, or findings.

Kelly Johanna Molano Betin, Leo Danny Valencia Pinto · Ibero Ciencias - Revista Científica y Académica - ISSN 3072-7197 · Colombia

A mixed-methods, non-experimental descriptive study tested a school-based agroecology pedagogical strategy to strengthen food security at Institución Educativa Técnico General José Joaquín García, Sede 10 Peñolcitos, in Casabianca, Tolima, Colombia. Following a quantitative diagnostic questionnaire, a teaching sequence combining conceptual training, an agroecological school garden, and a healthy cooking workshop was implemented; students showed favorable preconceptions about agroecology, food security, and the garden but specific gaps in understanding its full scope beyond production, and the training activities narrowed those gaps.

Sasha Gillies-Lekakis, Heidi Zogbaum · International Journal of Cuban Studies · Cuba

Cuban historiography is typically divided into pre-1959 and post-1959 periods, but land-use practices show continuity across both. Two hundred years of export-oriented sugar planting left Cuba dependent on food imports, first from the United States and later the Soviet Union. After 1991, Cuba had to find ways to feed itself on land depleted by two centuries of monoculture. The introduction of permaculture — first developed in Australia and suited to urban agriculture — helped Cubans address some of these food supply problems, making Cuba a world leader in permaculture practice.

· Wikipedia · Global

The English Wikipedia article 'Permaculture' defines it as an approach to land management and design based on observing flourishing natural ecosystems. Franklin Hiram King introduced the term 'permanent agriculture' in 1911, and Bill Mollison and David Holmgren coined 'permaculture' with the 1978 publication of 'Permaculture One'. It outlines three core ethics (care of the earth, care of people, and setting limits to population and consumption), Holmgren's twelve design principles, and practices such as hugelkultur, sheet mulching, and companion planting.

· Wikipedia · Cuba

This Wikipedia article on Cuban agriculture states the Soviets provided 63% of Cuba's food imports and 90% of its petroleum before 1990; after the collapse, agricultural production fell 54% between 1989 and 1994. By 2002, 35,000 acres (140 km2) of urban gardens produced 3.4 million metric tons of food, 90% of Havana's fresh produce came from local urban farms, and by 2003 more than 200,000 Cubans worked in the expanding urban agriculture sector. More recently, cooperatives and family farmers manage about 69% of Cuba's agricultural land.

Global Network of Lighthouse Farms (Wageningen University & Research) · Global Network of Lighthouse Farms (Wageningen University & Research) · Cuba

This profile of Organopónico Vivero Alamar from Wageningen University's Global Network of Lighthouse Farms describes a UBPC (Basic Unit of Cooperative Production) founded in 1997 by 5 cooperative members, starting as an 800 sqm manually irrigated tree nursery. It has since grown to 10.14 ha with 150 cooperative members, 42 of them women, including nurseries, a 0.45 ha greenhouse, a rustic lab for breeding entomopathogens, a mycorrhizal fungi propagation center, and small-scale fruit and vegetable processing facilities. The page notes the farm has had to close due to COVID-19-related economic hardship and wildfires.

· Wikipedia · Global

The 'Forest gardening' URL now redirects to a section within Wikipedia's merged 'Agroforestry' article. Per that section, forest gardening is a low-maintenance, perennial, woodland-modeled food production system practiced since prehistoric times in the tropics; horticulturist Robert Hart coined the term and adapted it for temperate climates in the 1980s. The article states Kerala, India has 'no fewer than three and a half million' forest gardens, citing one 0.12-hectare plot found to contain 23 young coconut palms, 12 cloves, 56 bananas, 49 pineapples, and 30 pepper vines.

· Wikipedia · Global

This Wikipedia article on the Haber (Haber-Bosch) process for industrial ammonia synthesis states that, as of 2018, the process produced 230 million tonnes of anhydrous ammonia per year, and that 'nearly 50%' of the nitrogen found in human tissues originated from it. Ammonia production is said to account for 1-2% of global energy consumption, 3-5% of natural gas production, and 3% of global carbon emissions, while nitrogen use efficiency is typically less than 50%, with farm runoff from excess use disrupting biological habitats. The article also credits the process with supporting global population growth from about 2 billion in the early 20th century to over 8 billion today.

· Wikipedia · Global

This Wikipedia article on nitrogen fixation (the chemical process converting inert nitrogen gas into biologically usable nitrogen compounds) states that, as one legume example, nitrogen fixation by red clover can range from 50 to 200 lb/acre (56 to 224 kg/ha). It states the marine cyanobacterium Trichodesmium is thought to account for 'almost half' of nitrogen fixation in marine systems globally, and that the amount of nitrogen fixed in the ocean is at least as much as on land. It also credits the spread of Haber-process nitrogen fertilizer with helping expand the human population from about 2 billion in the early 20th century to over 8 billion today.

· Wikipedia · Global

The URL for 'Peak phosphorus' now redirects to the Reserves section of Wikipedia's 'Phosphorus' article. Per a 2023 USGS estimate, world commercially extractable phosphate rock reserves are 72 billion tons, against 2022 world mining production of 220 million tons — implying roughly 300 years of supply at zero growth. Before new deposits were discovered in Norway in 2023, Earth's commercially affordable phosphorus reserves were expected to be depleted in 50-100 years. Reserve estimates are described as contested: a 2010 IFDC report is criticized by a 2014 review as presenting 'an inflated picture of global reserves,' particularly for Morocco, where largely hypothetical and inferred resources were simply relabeled 'reserves.' The article also states that a shortage in rock phosphate or significant price increases might negatively affect world food security. Mitigation measures cited include reducing agricultural runoff (no-till farming, contour tilling, windbreaks), incinerating phosphorus-rich sewage sludge and recovering the ash, and recovering phosphorus-rich materials such as struvite from waste — though current recovery technologies are described as not yet cost-effective given phosphorus market prices.

· Wikipedia · Global

This Wikipedia article on 'metabolic rift' explains that German agricultural chemist Justus von Liebig, in his 1840 'Organic Chemistry in its Application to Agriculture and Physiology,' argued that if all solid and liquid excreta of city inhabitants were returned to farmers, land productivity could be maintained for centuries virtually unimpaired. Marx, combining his understanding of the labor process with Liebig's analysis, wrote in Capital Vol. 1 that capitalist production, by concentrating population in cities, 'disturbs the metabolic interaction between man and the earth' and prevents the return of soil constituents consumed by humans as food and clothing — defining this as 'an irreparable rift in the interdependent process of social metabolism.' John Bellamy Foster, in his 2000 book 'Marx's Ecology: Materialism and Nature,' reassessed Marx's ecological perspective, arguing the metabolic rift concept enabled the development of a critique of environmental degradation. The article notes that as food and fiber were transported over long distances, soil nutrients moved to cities as agricultural produce but were not returned as human and animal waste, producing 'a one-way flow of materials' — a plundering of the soil to sustain society's reproduction.

· Wikipedia · Global

The Wikipedia article on compost describes it as a mixture used as plant fertilizer that improves soil's physical, chemical and biological properties, made by decomposing plant/food waste and manure. It requires four elements — carbon, nitrogen, oxygen and water — with an optimal carbon-to-nitrogen ratio of about 25:1. About 20% of landfill waste is compostable material such as food, and composting reduces methane emissions compared to landfilling organic material.

· Wikipedia · Global

A Wikipedia article on terra preta, a fertile anthropogenic dark soil found across the Amazon Basin, formed between 450 BCE and 950 CE and rich in low-temperature charcoal and pottery shards. It notes black carbon content reaching up to 9% (versus 0.5% in surrounding soils), depths of up to 2 meters, a regeneration rate of about 1 centimeter per year, an estimated coverage of 0.1-0.3% (6,300 to 18,900 square kilometres) of the Amazon Basin, and modern biochar-based attempts to recreate it.

· Wikipedia · Global

Soil is a complex three-phase system of minerals, organic matter, gases, water, and organisms that supports plant growth and soil life. A typical soil is about 50% solids (45% mineral, 5% organic matter) and 50% pore space, with microbial density around 10^8 organisms per gram and pore-space CO2 concentrations 10 to 100 times atmospheric levels.

· Wikipedia · Global

Soil compaction is a geotechnical process that removes air between soil particles under stress, increasing density. It is essential as a support layer in construction but reduces water infiltration and root growth in agriculture. The degree of compaction is assessed relative to maximum dry density determined by tests such as the Proctor test; the article presents no specific numeric data.

Gao, Si, Burce, Katrina, Smith, Laney, Espinoza, Nina, Melbourne, Alfred · Frontiers in Soil Science · 米国（カリフォルニア州ウェスト・サクラメント）

Urban agriculture soils are commonly amended with compost, yet how such systems respond functionally to biochar across application rates is poorly understood. In a field experiment at Three Sisters Gardens (West Sacramento, CA, USA), biochar was applied at 0, 10, 20 and 30 t/ha to compost-amended plots under corn and squash, and late-season soils were analysed for physical, chemical and biological indicators. Intermediate rates (10–20 t/ha) improved aggregate stability and increased soil respiration; the highest rate (30 t/ha) produced the strongest biological responses, including higher microbial biomass, fungal:bacterial ratios and extracellular enzyme activities in nitrogen and phosphorus cycling. Soil pH and cation exchange capacity did not differ significantly among treatments. Regression analyses indicated nutrient availability was more strongly associated with microbial indicators than with bulk soil chemistry, consistent with microbial mediation of biochar-associated nutrient dynamics, and the patterns held broadly across both cropping systems.

· Frontiers in Sustainable Food Systems · Global

A thematic review synthesising global trends, innovations, governance frameworks and pathways to sustainability in urban agriculture, mapping the field's current state and future directions including citizen participation, policy support and environmental challenges.

Zhang Y., Chen T., Gasparri E., Lucchi E. · Sustainability (MDPI), 17(2):666 · Australia (Sydney)

Proposes a modular agrivoltaics building envelope that physically integrates thin-film PV and hydroponic farming into the building skin itself, rather than treating solar and agriculture as separate systems. Using a circular design approach with multi-objective optimization of energy, light, water and structure (case study: Sydney), it extends food-plus-energy production from rooftops to walls and facades, highlighting space-utilization and system-integration gains for net-zero urban architecture.

Ranalli et al. · Journal of Applied Ecology · Global (urban ecosystems)

2025 research on how urban agriculture and urban planning enhance pollinator habitats in changing landscapes. Urban environments offer benefits to pollinator communities: lower pesticide use, greater variety of floral resources, and increased landscape heterogeneity. Urban agriculture serves as a pollinator reservoir and source area for adjacent rural regions, contributing to food security, poverty alleviation, and pollinator conservation.