Research & reports

Alemseged Gerezgiher Hailu, daniel girmay, samuel ataklti · Discover Food · Sub-Saharan Africa

This scoping review analyzed 155 sources (2009–2024) on urbanization's impact on food security in Sub-Saharan Africa. Findings showed rapid urban expansion converted 30% of peri-urban agricultural land in some regions, increasing dependence on imported staples, and low-income households spend 60–80% of income on food. A policy gap was identified, with only 12% of countries having supportive policies and 19% of cities designating land for farming.

Nthabeleng Tamako, Joyce Chitja · Agriculture & Food Security · South Africa

This study examined the impact of climate change on urban food gardens in Sobantu and Mpophomeni townships in Pietermaritzburg, KwaZulu-Natal, South Africa. Face-to-face interviews with 103 randomly selected participants revealed that climate change disproportionately affects resource-limited urban farmers, leading to erratic rainfall, pests, and natural disasters. Elevated temperatures, shifting weather patterns, and new pests and diseases significantly impact food gardens, affecting seed and crop selection and contributing to food insecurity.

Never Assan, Justice Sibanda, Betty Mukuwapasi, Reason Rumbidzai Charachimwe, Edmore Masama · Journal of Frontiers in Multidisciplinary Research · Sub-Saharan Africa

Urban animal agriculture (UAA) in Sub-Saharan Africa is presented as a solution for food security but faces challenges including gender inequality, climate change, inadequate legislation, and environmental degradation. While UAA aims to enhance household food security and alleviate poverty, it also encounters environmental issues such as resource competition, water resource strain, improper manure management, greenhouse gas emissions, noise, and nuisance. Sustainable UAA requires semi-intensive silvopastoral and mixed crop and livestock systems to reduce environmental impact and enhance local food production.

Mugabo Kalisa G. · Idosr Journal of Computer and Applied Sciences. · Sub-Saharan Africa

A review article addresses how, in Sub-Saharan Africa (SSA) where malaria transmission is increasing in urban and peri-urban areas due to rapid urbanization and inadequate infrastructure, urban agriculture — a vital livelihood strategy in peri-urban SSA — often intersects with poor water management practices, creating favorable breeding grounds for malaria vectors, particularly Anopheles mosquitoes. It examines the complex relationship between urban agriculture, water management and mosquito breeding in peri-urban areas, including how irrigation systems, water storage and waste management contribute to malaria transmission, and discusses the implications for malaria control. It also reviews emerging technologies such as remote sensing, GIS and mobile health platforms that can enhance mosquito surveillance and community involvement, and calls for a multi-sectoral approach spanning urban planning, vector control and community-based interventions, along with sustainable urban agricultural practices to mitigate malaria risks in SSA.

A. K. Ahmed, Rasheed Abiodun KURANGA, Oluwadara Latifat ISOLA-MUYIDEEN · International Journal of Research and Innovation in Social Science · Nigeria (Ilorin)

This study assessed the sustainability of environmental management practices among peri-urban rice farmers in Ilorin, Nigeria, using a sustainability index. It found that many practices were less sustainable, with 69.51% of farmers relying on chemical sprays and 69.85% using chemical fertilizers. The overall Environmental Management Practices Sustainability Index (EMPSI) for all farmers was 0.492, placing them in the moderately sustainable category.

Mahacla Odongo, Caleb Mireri, Peter Mwangi · Environmental Technology and Science Journal · Kenya (Nairobi)

The Nairobi River riparian reserve in Kenya has undergone immense land use and land cover changes over the past 20 years due to urban development. A survey of 650 respondents revealed that urban agricultural activities dominated the upper segment at 69%, commercial ventures constituted 79% of the middle segment, and residential usage comprised 89% in the lower segment. These activities caused significant degradation from crop cultivation of river slopes, pollution infiltration, and loss of biodiversity, indicating a severe depletion of the riparian space's functions.

Fuchaka Waswa, Duncan Gichabe, Ruth Kahuthıa-Gathu · Journal of the Kenya National Commission for UNESCO · Kenya (Ruiru)

This study investigated land use changes in Ruiru Sub-County, Kenya, from 1988 to 2024 using GIS. By 2024, agricultural land had decreased by 45.62%, while urban land use increased by 509%, and bare/rocky areas rose by 133% due to abandoned stone mining. The decline in agricultural land leads to reduced industrial crop areas and a shift to leafy vegetables, with an expected increase in agro-chemical use in intensive peri-urban farming.

Vidjinnagni Vinasse Ametooyona Azagoun, Kossi Komi, Djigbo Félicien Badou, Expédit Vissin, Komi Sélom Klassou · Geographies · Africa

Drawing on socio-economic, techno-agronomic, and perceptual data collected from 369 growers in the Grand Nokoué region of Benin, this study combined multiple correspondence analysis (MCA) with ascending hierarchical analysis (AHA), confirmed by K-means partitioning, to identify profiles of climatic vulnerability among urban market gardeners. Three distinct vulnerability groups were identified, differing in socioeconomic, technical, and territorial characteristics and in their exposure to flooding, drought, and dry spells. The most vulnerable farmers were disproportionately young women with low incomes, limited access to land, and reliance on manual irrigation in flood-prone areas. The findings point to an uneven distribution of adaptive capacity and a need for public policies tailored to strengthen the resilience of small-scale, low-income, and land-insecure urban farmers who are exposed to these climate-related risks.

Olivier Grünberger, Radhouane Hamdi, Manon Lagacherie, Hanène Chaâbane · Journal of Environmental Science and Health Part B · Africa

Two years of monthly water sampling and hydrological monitoring at the outlet of the Wadi Guenniche watershed (86 km², with rainfed cereal, legume and orchard cultivation and irrigated market gardening) in northern Tunisia, a tributary of the Bizerte coastal lagoon, tested for 469 pesticide active ingredients and metabolites. Twenty-nine pesticide active ingredients and 2 metabolites were detected in the water, 24 of which are authorized for use in Tunisia; 14 of the authorized substances had never before been mentioned in farmer surveys. The five most frequently detected herbicides and metabolites were AMPA (100%), glyphosate (94%), simazine (94%), 2,4-D (70%) and deisopropylatrazine (DIA, 47%). The detection frequency and concentration range suggest phytosanitary pressure and water contamination comparable to the northern Mediterranean shore, indicating a need for further study of pesticide use and fate on the southern shore, particularly in Tunisia.

F.E. Awoyelu, R.A. Mebo · Agro-Science · Nigeria (Osun State)

This study assessed the effects of artisanal sand mining on peri-urban agriculture in Ife East and Ife Central Local Government Areas, Osun State, Nigeria, from 2015 to 2019. Data from 120 respondents (landowners, cultivators, residents) showed that cultivated land area decreased by 24.8% (from 48% to 23.2%), while sand-mined area substantially increased by 20.4% (from 14.6% to 35%). Landowners' decision to part with land for sand mining increased with age, household size, and farming as primary occupation, but decreased with higher education levels.

Abigail Benson, NICHOLAS O EHISIENMHEN, EUNICE T ADEWALE, R ANIMASAHUN-OLADIMEJI, TOBA R ARIBILOLA, RAZAQ A AFIZ, Augustine Okeke, Oliver P. John, Idris Ahmad Isa, BADRAT O IMRAN, KELVIN D DIRISU, OMOTOYE O OMISORE · Greener Journal of Agricultural Sciences · Nigeria (Ondo State)

This study assessed the impact of urbanization on agricultural land in Akure South Local Government Area, Ondo State, Nigeria, using populated figures and land use data from satellite images for 2002, 2012, and 2022. GIS analysis revealed an increase in settlement and a decrease in agricultural land from 2002 to 2022. Urbanization significantly decreased agricultural land, farming activities, and farm size, driven by increasing settlement and built-up areas.

Bernardino Bernardo, Elisa Eda Nhambire, Alice Castigo Binda Freia, Octávio Manuel de Jesus, José Júlio Júnior Guambe, Zacarias Alexandre Ombe, Gustavo Sobrinho Dgedge · Cadernos de Geografia · Mozambique (Maputo)

This mixed-method study analyzed the impacts of hailstorms on urban horticulture in northern Maputo City and Matola, Mozambique, following a storm on June 1, 2021. The study found total and partial destruction of ready-to-cut vegetables, including cabbage, lettuce, and onions, across all production areas. This resulted in heavy financial losses for farmers and a significant increase in vegetable prices in local markets.

Anne-Louise Fritz, Ramia Jannoura, René Beuschel, Christoph Steiner, Andreas Buerkert, Rainer Georg Joergensen · Chemical and Biological Technologies in Agriculture · Africa

This 2-year study in semi-arid Ouagadougou and sub-humid Tamale, West Africa, measured the effects of biochar and N fertilization on soil microbial biomass carbon, fungal ergosterol, and functional diversity. Sole biochar addition did not affect soil chemical or biological properties, but biochar with N fertilization increased microbial respiratory response. N fertilization decreased soil pH by 1.1 units in both cities, and a pH of 4.7 led to reduced microbial biomass carbon and ergosterol contents in Tamale. An N fertilizer-induced decline in soil pH below 5 should be avoided, as it decreased microbial biomass carbon and microbial functional diversity.

Shabu Terwase · International Journal of African and Asian Studies · Nigeria

This study assessed the impact of urbanization on agricultural land in Makurdi Local Government Area, Benue State, Nigeria, using population figures and land use data from 1997, 2007, and 2017. GIS analysis revealed an increase in settlement and a decrease in agricultural land, with 99.51 hectares of agricultural land converted to settlement between 1997 and 2017. Urbanization significantly decreased agricultural land, activities, and farm size in the study area.

Mekonnen Amberber Degefu, Mekuria Argaw, Gudina Legese Feyisa, Sileshi Degefa · ENVIRONMENTAL SYSTEMS RESEARCH · Ethiopia

This study characterized and compared the Spatio-temporal responses of ecological land to urban landscape dynamics in Bahir Dar, Addis Ababa, Adama, and Hawassa cities in Ethiopia for the last three decades (1990–2020). Three sets of Landsat satellite images, field observations, and urban land indexes were used to produce landscape maps and geo-spatial data analysis. Results showed that in all cities, ecological land had changed intensely regarding its quantity and spatial pattern, and the substantial expansion of built-up ecosystems was manifested at the cost of ecological land.

Solomon 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.

Bereket Geberselassie Assa · Civil and environmental research · Ethiopia

A study of Wolayta Zone Sodo Zuria Woreda in southern Ethiopia used GIS and remote sensing to analyze how human intervention affects the agricultural system. It found that urbanization driven by demand for residential land, a 2.66% increase over nine years, has produced food insecurity and raised crop production costs in local markets. Forestland declined at a rate of 0.295% per year, of which 0.09% was converted to residential land. Land use classification from 30 m Landsat 7 imagery was evaluated using the Analytic Hierarchy Process with a consistency ratio of 0.016%, and the study notes that the impact of deforestation on urban agriculture and livelihoods in this part of southern Ethiopia's highlands had not previously been scientifically studied.

Joshua Jonah Kunda, Ahmed Abubakar Jajere, E. A. Otabe, Chindo Musa Muhammed, Umar Muhammed Bibi, Yusuf Maina-Bukar · Environment and Pollution · Nigeria

This study in Makurdi, Benue State, Nigeria, used geospatial technology to assess agricultural land vulnerability to flooding, deriving factor weights (rainfall 25%, elevation 22%, slope 20%, drainage density 13%, land use/cover 12%, soil type 8%) through pairwise Analytical Hierarchy Process comparison (consistency ratio 0.078) and a weighted overlay model in ArcGIS 10.4. Farmland along the floodplains of the River Benue fell within the very highly vulnerable category, with elements at risk totaling 537.6 units of farmland (66.1%), 40.5 units of irrigation land (5.0%), and 125.8 units of built-up land (15.5%).

Achamyeleh Gashu Adam · IntechOpen eBooks · Ethiopia

A case-study and desk-review analysis of how new urban built-up properties form in the transitional peri-urban areas of Ethiopia. These areas are described as sites of intense competition between agricultural and non-agricultural land use, where rural agricultural land rights are vanishing. The study finds that both formal and informal actors play a significant role in converting peri-urban agricultural land into non-agricultural urban built-up property, and that these properties result from land-use conversion through both formal and informal channels.

Delphine Manka’abusi, Désiré Jean‐Pascal Lompo, Christoph Steiner, Mariko Ingold, Edmund Kyei Akoto-Danso, Steffen Werner, Volker Häring, George Nyarko, Bernd Marschner, Andreas Buerkert · Journal of Plant Nutrition and Soil Science · Sub-Saharan Africa

To quantify carbon and nitrogen losses in urban and peri-urban agriculture soils in West Africa, this study measured CO2-C, N2O-N, and NH3-N fluxes from irrigated fields in Ouagadougou, Burkina Faso, and Tamale, Ghana, under different fertilization and (waste)water regimes. Compared with unamended controls, fertilizer application increased average cumulative CO2-C emissions by 103% over eight cropping cycles in Ouagadougou and by 42% over seven cropping cycles in Tamale. Total emissions across all cropping cycles reached 14 t C/ha in Ouagadougou — 73% of the carbon applied as organic fertilizer over two years at that site — and 9 t C/ha in Tamale. Fertilizer application increased N2O-N emissions in Ouagadougou by 37-360% across cropping cycles and NH3-N losses by an average of 670%, but had no significant effect on N2O-N losses in Tamale. Wastewater irrigation did not significantly raise CO2-C emissions in Ouagadougou, but in Tamale CO2-C emissions were 71% higher on wastewater plots (1.6 t C/ha) than on controls (0.9 t C/ha); wastewater had no significant effect on N2O-N or NH3-N emissions at either site. Biochar did not affect N2O-N or NH3-N losses but could help reduce CO2-C emissions from urban garden soils.

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.

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.

Shailesh Deshpande, Priyanka Verma, Piyush Yadav, Jay Gubbi, P Balamurali · Asian Journal of Geoinformatics · South Africa (Johannesburg)

Land Use Land Cover (LULC) changes in Johannesburg City, South Africa, were analyzed using Landsat imagery from 2000 to 2016. The analysis revealed that impervious surface increased by 57.03% during this period, leading to a 47.8% loss of urban vegetation (grass, tree cover) and urban agricultural land. Additionally, soil and water loss amounted to 16.75%.

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.

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.