Research & reports

Michel Shengo Lutandula⃰, Fabien Ilunga Mpanga · The Global Environmental Engineers · Democratic Republic of Congo (or Africa)

In Katuba municipality, Lubumbashi, Democratic Republic of Congo, irrigation water, soil, and harvested amaranth from an area of urban amaranth cultivation were analyzed for chemical and microbiological pollutants. Water and amaranth were polluted on both mineral and microbial fronts, while soil was not; water samples contained Paramecia, Entamoeba histolytica eggs, fecal contamination indicator germs, mesophilic flora, and pathogens including Aeromonas hydrophila and Pseudomonas aeruginosa. Amaranth cobalt concentrations exceeded quality standards and the plants were contaminated with Paramecia, Entamoeba histolytica eggs, Escherichia coli, and Klebsiella planticola, leading to the conclusion that consuming these amaranths poses health risks to the population.

Peter Sanjo Adewale, Sunday Clement Olubunmi Makinde, V. Kusemiju, Olawole O. Obembe · Journal of sustainability and environmental management · Nigeria

This study measured and compared lead (Pb), cadmium (Cd) and manganese (Mn) concentrations in soil and leafy vegetables (Amaranthus hybridus, Celosia argentea, Corchorus olitorius) using atomic absorption spectrophotometry at Urban Expressway Farms (UEF) and Peri-urban Road Farms (PRF) in Lagos State, Nigeria. It found the highest Pb concentration (0.93+/-0.06) in Celosia argentea at UEF, and the highest Cd (0.51+/-0.11) and Mn (0.98+/-0.02) concentrations in Amaranthus hybridus at UEF, with Pb in Celosia argentea 5 m from the expressway and Cd in Amaranthus hybridus 10 m from the expressway exceeding WHO/FAO permissible levels; heavy metal residue levels were driven more by farm location than by vegetable type, and the study calls for regular monitoring to prevent consumption of contaminated leafy vegetables and recommends farmers cultivate fields farther from expressways.

Chanie Derso Misganaw · Agriculture Forestry and Fisheries · Ethiopia

This review paper highlights the current lack of urban agriculture practice in Ethiopian towns and emphasizes its significance. Urban agriculture contributes to food self-sufficiency, social goodness, economic profitability, and environmental health, and is stated as the most appreciated means to improve livelihoods, generate income, create job opportunities, and fight against famine, depression, anxiety, and the spread of coronavirus. The paper discusses the types, principles, and prospects of urban agriculture based on updated information.

Adugnaw Maru Gezahegn, Fekadu Fufa, Esayas Alemayehu, Abebe Beyene · Journal of Chemistry · Ethiopia (Modjo city)

This study investigated the spatial distribution and speciation of chromium in water, soil, and edible plants in tannery-contaminated areas of Modjo city, Ethiopia. Total chromium in the Modjo River was 20.6 mg L−1 upstream, and soil Cr (III) and Cr (VI) concentrations were found to be higher than guideline values. Chromium concentrations in edible plants were also significantly higher than in control areas, with roots accumulating more chromium than leaves and fruits. It was concluded that water, soil, and edible plants in this area contain chromium concentrations higher than recommended for a healthy environment and human consumption.

Mawuna Donald Houessou, Annemijn Cassee, B.G.J.S. Sonneveld · Sustainability · Benin

A Rapid Food Security Appraisal was conducted among 240 rural and urban dwellers in southern Benin to evaluate the effects of the COVID-19 ‘cordon sanitaire’ on food consumption. The pandemic affected food security pillars in both rural and urban areas, with the steepest decline observed among those inside the cordon sanitaire, particularly rural producers and urban inhabitants without allotment gardens. Increased food prices, logistics disruptions, and movement restrictions were cited as reasons, while access to allotment gardens effectively mitigated the crisis for households.

Anthony Kamara, Foday Thullah · Journal of Nuclear Technologyin Applied Science (JNTAS) /Journal of Nuclear Technologyin Applied Science (JNTAS) · Africa

A study measured background radiation at the two major dumpsites in Freetown, Sierra Leone — Kingtom and Granville Brooke — which are also used for urban agriculture and where youths scavenge scrap metals and plastics daily. Using a portable Radiagem survey meter and GPS, researchers took 10 in-situ dose-rate measurements at each site. The mean equivalent dose rate was 0.8 mSv/year at Kingtom and 1.1 mSv/year at Granville Brooke; Kingtom slightly exceeded the UNSCEAR permissible limit but stayed below the ICRP limit, while Granville Brooke exceeded both the UNSCEAR and ICRP limits. The study concludes both dumpsites could become unsafe in the near future from cumulative radiation exposure for workers, scavengers and other exposed individuals.

TP Modibedi, MMS Maake, MR Masekoameng, SS Tekana, Oluwaseun Samuel Oduniyi · African Journal of Food Agriculture Nutrition and Development · South Africa

This quantitative study surveyed vegetable consumption patterns among 254 randomly sampled urban farmers from 30 community gardens (418 registered farmers) across six large townships in Emfuleni Local Municipality, Gauteng province, South Africa. Data were collected via face-to-face semi-structured questionnaires using 24-hour dietary recall and analyzed with SPSS version 23 using descriptive statistics and ordered logistic regression. 96.1% of farmers consumed vegetables as a relish and 93.3% as salad, most often at dinner because farmers were typically present in the gardens during the day. Of 10 independent variables tested, only age group, education level, and main income source showed a statistically significant positive association with consumption patterns. The study recommends incorporating vegetables into all three daily meals and providing education on the importance of vegetable consumption.

I.O. Amao · IntechOpen eBooks · Sub-Saharan Africa

This chapter conducted an empirical review of urban horticulture in cities across Sub-Saharan Africa, aiming to specify its benefits in the region. The review concluded that governments in these countries require political will to realize the identified advantages of urban horticulture, which include food and nutrition security, healthy environments, and sustainable livelihoods. It recommends raising awareness among stakeholders like politicians, policymakers, and urban households to integrate urban horticulture into land use planning.

Michael Rudolph, Evans Muchesa, Florian Kroll · International Journal of Natural Resource Ecology and Management · South Africa

This paper reflects on key socio-economic challenges in South Africa and the role of urban agriculture in addressing health disparities and promoting ecological health. Using a structured mixed literature review and primary/secondary data, the study demonstrates the high prevalence of food and nutrition insecurity. However, it also emphasizes the positive outcomes of an integrated approach to addressing nutrition and food security, suggesting that multi- and trans-disciplinary methods based on ecological health promotion can improve food security, public health, and socio-economic development.

Crippina Lubeka, Judith Kimiywe, Hudson Nyambaka · Research Journal of Food Science and Nutrition · Kenya (Makueni County)

This study assessed the effect of school garden interventions on improving serum zinc, iron, and retinol levels, and diet diversity, among pre-school children in Mulala ward, Makueni County, Kenya. A quasi-experimental design was adopted with 63 children, where intervention early childhood centers provided vegetables and animal proteins from school gardens for six months. Post-intervention, a significant difference was found in the mean dietary diversity score between the intervention and control groups, and a significant positive correlation was observed between serum hemoglobin, retinol, zinc levels, and dietary diversity in the intervention population.

Reuben Nwoye Okechi, Edna Ifeoma Chukwura, Christian Okechukwu Nweke · Journal of Advances in Microbiology · Nigeria (Owerri)

This study, conducted in Owerri, Nigeria from June to December 2019, evaluated the interactive toxic effects of ternary mixtures of sodium dodecyl sulfate (SDS) and divalent metals on Serratia marcescens (SerEW01) from the Otamiri River, a source for urban farming. The study found that both concentration addition (CA) and independent action (IA) models predicted lower toxicities compared to experimentally observed data. The Toxic Index and Model Deviation Ratio indicated a synergistic interaction of SDS and metal ions, resulting in higher combined toxicities than predicted, posing environmental hazards due to co-contamination.

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.

Sara E. Benjamin‐Neelon, Tiange Liu, Eve S. Puffer, Liz Turner, Daniel A. Zaltz, Andrew Thorne‐Lyman, Sherryl Broverman · Current Developments in Nutrition · Kenya

This natural experiment in rural Kenya evaluated whether school gardens improved dietary diversity in children. Gardens were installed in two primary schools, with two comparison schools, and dietary intake was measured for 855 children in 2013 and 688 in 2014. All children's dietary diversity scores worsened post-intervention, likely due to a severe drought in 2014. Although some differences were observed in specific food groups, these could not be attributed to the school gardens.

Aurillia Manjella, Alessandra Grasso, Victor W. Wasike · · Africa

A report on the Biodiversity for Food and Nutrition project in Busia county, western Kenya, describes school gardens that supply or complement school feeding programmes as a practice for mobilizing biodiversity and improving dietary diversity among schoolchildren. Kenya is said to have more than 200 African leafy vegetables (ALVs), and the project gives children opportunities to acquire agricultural skills focused on cultivating nutrient-rich ALVs; the report notes that school gardening has long been part of education in Kenya, especially in rural areas dating to colonial times.

Georgette N. Ngweme, Dhafer Mohammed M. Al Salah, Amandine Laffite, Periyasamy Sivalingam, Dominique Grandjean, Konde Nkiama Numbi Joël, Crispin K. Mulaji, Florian Breider, John Poté · The Science of The Total Environment · Africa

This study investigated levels of persistent organic pollutants (POPs) in irrigation water, soil, and Amaranthus viridis from gardening sites in Kinshasa, Democratic Republic of the Congo, to assess environmental and human health risks. A survey of pesticide and fertilizer use was conducted with 740 market gardeners, and POPs (organochlorine pesticides, PCBs, PBDEs, and PAHs) were analyzed in irrigation water and 144 vegetable samples. The highest PAH levels were found in A. viridis at all sites studied; the sum of seven PCB congeners ranged from 15.89 to 401.36 ng/g; chlorpyrifos-ethyl and p,p'-DDE were the predominant OCPs detected; and among PBDEs, only BDE47 was quantified at notable concentration in the plants, with none detected in irrigation water. Higher estimated daily intake values indicated that consuming the leafy vegetables could be associated with increased health risks, though calculated incremental lifetime cancer risk values indicated no potential carcinogenic risk for the local population. The study recommends implementing urban agriculture control programs for POPs and fertilizer use in Kinshasa to protect public health.

Akakpo D. B., Achigan-Dako E. G. · Agronomy · Benin

Interviews with 360 respondents across three southern Benin villages on three traditional leafy vegetables, analyzing how use and knowledge transmission from parents to children vary by generation, gender, and village.

· Journal of Animal and Plant Sciences (J Anim Plant Sci ) ISSN 2071 – 7024 · Africa

A study in Port-Bouët, Abidjan, examined market gardeners' phytosanitary practices and pesticide residue incidence on lettuce. It found that 39.6% of pesticides used were not recommended for market gardening, 86.84% of gardeners did not protect themselves during application, and 80.26% did not observe pre-harvest intervals. Consequently, 93.33% of lettuce samples did not comply with Codex Alimentarius and EU standards due to high pesticide residue contamination.

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.

Chinwe Okonkwo, A. Bello · Open MIND · Nigeria (Maiduguri)

This study investigated the role of urban community gardening programs in generating social capital among 312 internally displaced persons in Maiduguri, Nigeria. A cross-sectional survey across three displacement-affected wards measured bonding, bridging, and linking social capital. Participation in community gardens was significantly associated with increased bonding and bridging social capital, with 78% of respondents forming new trusted relationships across ethnic or village backgrounds. Frequency of garden participation positively predicted perceived community solidarity.

Nicolette Tamara Jonkman, Esmee D. Kooijman, Karsten Kalbitz, Nicky Pouw, Boris Jansen · SOIL · Kenya (Kisumu)

This study in Nyalenda urban gardens, Kisumu, Kenya, investigated how female farmers' knowledge and practices influence soil nutrient status. Soil analysis revealed that intercropped fields had significantly lower total soil nutrients than fields with only manure, despite cowpeas theoretically increasing soil N. Female farmers' knowledge was limited to practical and sensory aspects, and intercropping did not increase soil nutrient content due to socioeconomic factors like poverty.

Kouassi Joseph Kouakou, Ahoua Edmond Sika, Seu Jonathan Gogbeu, Koffi Bertin Yao, M. Bounakhla, Denézon Odette Dogbo, Yves‐Alain Bekro · · Africa

This study compared the accumulation potential of five trace metals (cadmium, copper, lead, zinc, and nickel) in lettuce, spinach, and amaranth grown at market gardening sites in Abidjan, Côte d’Ivoire. Using principal components analysis, it was found that lettuce had a greater capacity for accumulating these metals compared to spinach and amaranth. Amaranth and spinach from the three sites showed nearly identical metal accumulation capacities.

Zebenay Shitaye · Developing Country Studies · Ethiopia

This study investigated the role of Urban Agriculture (UA) in improving household income and dietary diversity in Bure and Finoteselam Towns, Ethiopia. A survey was conducted with 242 respondents from two Kebeles, selected based on their UA potential and existing training, and data were analyzed using SPSS. Major reasons for UA engagement included earning additional income (57.6%) and employment opportunities (18.5%). UA significantly enhanced dietary diversity for practitioners, particularly in the consumption of tuber roots, vegetables, fruits, eggs, legumes, and milk. However, constraints included inadequate extension support and training, shortages and high costs of inputs, inconvenient working places, lower product prices, transportation problems, and price manipulation by middlemen.

Erik Engel, Karin Fiege, Anja Kühn · · Africa

The UFISAMO project analyzed urban agriculture (UA) in Maputo and Cape Town. In Maputo, UA is the main income source for about 5% of the population, though it often does not cover monthly food costs, and a major challenge is the uncontrolled application of pesticides due to mono-cropping. In Cape Town's townships, UA plays a negligible role in income and food security due to small plots, sandy soils, water stress, and weak market links.

John Wakhanu, Hudson Nyambaka, Judith Kimiywe, Mildred Nawiri, Wilson Thagana · Journal of Food Science and Engineering · Kenya (Machakos County)

This study in Kangundo and Kilalani primary schools, Machakos County, Kenya, investigated the impact of African Indigenous Leafy Vegetables (AILVs) on children aged 6-10 years (N=66 in Kangundo, N=46 in Kilalani). Over two phases (13 and 12 weeks), an experimental group consumed AILVs from school gardens, while a control group did not. Endline analysis showed that the experimental group had significantly higher (p < 0.001) % Fat Free Mass, mean serum iron, and zinc levels compared to the control group.

Lemi Gonfa · · Africa

This paper reviewed the role of urban agriculture in socio-economic and environmental sustainability in Africa, drawing on theoretical and empirical literature. While urban agriculture is recognized for job creation, improved diet, and environmental benefits like urban greenery and biodiversity, challenges such as difficult land access, lack of experience, financial support, training, and credit facilities, as well as low land productivity, animal grazing, and theft, were identified. These factors present potential negative externalities and hinder the development of urban agriculture.