Research & reports

Ekaete Francis Asuquo · · Nigeria (Calabar)

The impact of urban expansion on agricultural land in Calabar and its environs, Nigeria, was investigated. A survey of 150 questionnaires and comparative assessment revealed a decrease in agricultural land in the fringes as urban expansion persists and increases. Before 2013, more farmers owned larger plots, but much of this agricultural land has been converted to housing estates, roads, leisure resorts, and schools, indicating that urban expansion has negatively impacted agricultural land, reducing food productivity and leading to farmer unemployment.

A. N. Mutune, M. A. Makobe, Mary Abukutsa‐Onyango · African Journal of Environmental Science and Technology · Kenya (Nairobi)

This study analyzed heavy metal content in 10 common African leafy vegetables and their rhizosphere soils from 25 sites along Nairobi Rivers, Kenya. While soil metal concentrations were generally within WHO/FAO permissible levels, except for some cadmium instances, all metals except copper in vegetables exceeded recommended limits at a few sites. This indicates potential heavy metal absorption from industrial and domestic effluent.

Salwa Tohmé Tawk, Mounir Abi Said, S.K. Hamadeh · Oxford University Press eBooks · Global

This study in the Middle East and North Africa region investigated the relationship between urban agriculture and food security in two peri-urban locations: Bebnine, Lebanon, and Wadi el Seer, Jordan. High food insecurity was prevalent in both locations, demonstrating that producers were more food insecure than non-producers. Food security was found to be strongly associated with poverty and the number of household members.

Yuki Sampei, Yuji Hara, Akinobu Murakami, Armand PALIJON, Kazuaki Tsuchiya, Makoto Yokohari · Journal of The Japanese Institute of Landscape Architecture · Philippines (Metro Manila)

The nitrogen supply-demand balance in compost and vegetable production on vacant lots in suburban residential districts of Quezon City, Metro Manila, was assessed. Analysis revealed that almost half of the subdivisions faced nitrogen oversupply, while several were in short supply. Current centralized composting facilities may not adequately support a continuous compost recycling system due to their distribution patterns. It was proposed that existing barangay-based policies on organic waste management and urban agriculture require greater flexibility and attention to coordination systems across subdivision boundaries.

Yuki Sampei, Yuji Hara, Akinobu Murakami, Armando M. Palijon, Kazuaki Tsuchiya, Makoto Yokohari · Institutional Repositories DataBase (IRDB) · Philippines

This study assessed the nitrogen supply-demand balance in compost and vegetable production on vacant lots in subdivisions and barangays in Quezon City, Metro Manila, using GIS. It found that nearly half of the subdivisions experienced nitrogen oversupply, while others faced shortages. Although cooperation among subdivisions within a barangay could improve nitrogen balance, the current centralized composting facilities were deemed insufficient to support a continuous compost recycling system due to their distribution patterns. The study concluded that current barangay-based policies on organic waste management and urban agriculture need greater flexibility and attention to inter-subdivision coordination across barangay boundaries.

Matilda Thelin · · Sweden

This qualitative study in peri-urban Uppsala, Sweden, identifies driving forces influencing land use decisions by commercial farmers and institutional landowners. It notes that approximately 700 hectares of land in Sweden are diverted from food production annually, with Uppsala Municipality showing the greatest change in 2013. The expropriation of agricultural land for urban development leads to farmers losing land resources and increased competition for remaining land, resulting in high land prices.

Suarau Odutola Oshunsanya, Tolafe Olayinka Adeniran · Agricultura tropica et subtropica · Nigeria (Ibadan)

A field experiment in Ibadan investigated the quality of irrigation water used for dry season vegetable cultivation along Ona-stream. Water samples from five isolated ponds and one locally dug well were analyzed for heavy metal status. Results showed high concentrations of Pb, Cr, and Co in soil from five farms (A-E) near the stream, and isolated pond water also contained Cr, Co, and Pb exceeding safe consumption thresholds. All vegetables irrigated with untreated isolated ponds contained Cd, Pb, and Ni concentrations above maximum permissible standards, posing potential risks to human health.

Eric Vaz, Marco Paìnho, Peter Nijkamp · European Planning Studies · Europe

This paper presents a spatial analysis integrating agricultural land use data inventories for Portugal with CORINE Land Cover data to assess change in the Algarve region. By overlaying the appropriation of agricultural land for urban use with population and urban data, it focuses on the consequences of specific regulations for the dynamics of land-use change. An integrated assessment of agricultural land loss found that agricultural land was being undermined by the consequences of urban sprawl. Building on this finding, the paper reviews existing decrees supporting sustainable development in the region, provides a qualitative assessment of future roles based on ethical values and economic efficiency, and offers a framework for policymakers regarding trends in the urban/agricultural dichotomy.

Achamyeleh Gashu Adam · African review of economics and finance · Ethiopia

In Ethiopia, all land is state-owned and granted to residents only as a holding right, with separate systems for rural and urban areas. Focusing on peri-urban agricultural land under growing pressure from urbanisation, this desk-review study analyzed existing survey research together with property-rights literature, theory, and current land-rights laws and policies. It found that new recipients of peri-urban land under the urban land-lease system obtain better and more extensive bundles of land rights than the indigenous, local peri-urban landholders who previously held that land.

Y. Saleh, Amul M. Badr, F. El Banna, A. Shahata · Science World Journal · Nigeria

Using a combination of remote sensing and GIS, this study assessed the rate of agricultural land-use change in the Kaduna metropolis, Nigeria, between 1980 and 2012, classifying and comparing four satellite images (Landsat MSS 1980, Landsat TM 1990, Landsat ETM+ 2005, and Nigeria Sat X 2012). The study found a significant reduction in agricultural land and continued disappearance of farmland over the period, which it links to loss of livelihoods, reduced food supply, and increased poverty. It states that this has raised concerns about the sustainability of urban and peri-urban agriculture (UPA) production in the study area, with small-scale farmers the most affected.

Ande O.T, Adetunji A. M, Akinpelu M. E, Senjobi B.A · Journals & Books Hosting (International Knowledge Sharing Platform) · Nigeria

Ibadan metropolis, Nigeria, home to about 6 million people, has raised growing concern over lowland soils in its periurban area, where much of the industrial waste transported by the River Ona is deposited; these soils are used for dry-season farming and contribute to food security. This study aimed to characterize periurban lowland soils around Ibadan and determine their vulnerability to industrial pollution, using a 50m x 50m grid with surface samples taken at 50m intervals, plus representative profile pits described using the USDA method, and particle-size and chemical analyses (phosphorus, nitrogen, exchangeable cations Ca/Mg/Na/K, manganese, and heavy metals including lead, copper, zinc, chromium, iron, and cadmium). Results showed the floodplain's surface soil was fertile, with high nitrogen (0.35 cmol/kg), phosphorus (51.25 cmol/kg), and potassium (0.61 cmol/kg), and phosphorus levels ranging from very high to toxic, between 28.99 and 87.70 ppm. Average heavy metal concentrations were lead 34.30 mg/kg, zinc 171.20 mg/kg, iron 83.97 mg/kg, copper 19.11 mg/kg, manganese 31.10 mg/kg, chromium 0.69 mg/kg, and cadmium 0.3 mg/kg. Predicted soil-to-plant heavy metal transfer coefficients (Pb 35-343; Cr 0.46-4.6; Zn 171-1712; Cu 19-191; Fe 83-840; Mn 31-281; Cd 0.1-10) indicated crops grown in the area could contain toxic levels of these metals; however, high yields and healthy plant condition observed in the field, together with farmer interviews, suggested that the high phosphorus level (28.99-87 ppm) may have inhibited uptake of some metals such as lead, zinc, and copper.

C.F.A. van Wesenbeeck, Valentijn Venus, M.A. Keyzer, B. Wesselman, D. Asare Kye · · Africa

This study examined two tomato production areas in Burkina Faso with potential for counter-seasonal production aimed at Ghanaian urban markets, identifying the main obstacles to developing a horticultural supply chain: the monopsony power of Ghanaian traders and insufficient road quality causing high mechanical-damage losses in transport. Using a spatial-temporal simulation model to assess transport effects on tomato quality, the study found refrigerated transport is not a necessary condition for successful trade, since climate conditions alone do not severely harm quality, and concluded that regional diversification of exports offers Burkina Faso producers the best opportunities for improving their position in the chain, given the persistent trader monopsony and infrastructure constraints.

Yves Cabannes, Isabel María Raposo · City · Europe

This paper conducted a comparative analysis of peri-urban agriculture in Lisbon and London to assess its contribution to migrant social inclusion and urban biodiversity. The study found that social inclusion patterns are city-specific; for example, Cape Verdean urban farming communities in Lisbon strengthen community bonds but do not necessarily lead to better integration into wider Portuguese society. Migrant urban farmers contribute to broadening biodiversity, primarily in Lisbon and to a lesser extent in London.

Zakir Hussain, Markus Hanisch · Journal of Environmental Planning and Management · India

This paper describes the adaptation of agricultural management practices in the urban periphery of Hyderabad, India, due to structural changes. Based on 120 farmer interviews, the study found that increasing costs for agricultural inputs like labor and land motivated farmers to intensify water, machine, and chemical use, which created problematic environmental impacts. Farmers also adapted by resorting to part-time farming and organizing efforts to share family labor.

Sarah James · Geographical Research · Australia (Sydney)

This paper examined the failure of Sydney's 'green zones' farmland protection policies, which were abandoned due to protests. The failure was attributed to a lack of consultation with Sydney's diverse small-scale farmers, rather than a rejection of farmland protection itself. Farmer interviews suggested that a bottom-up policy-making approach would have been more successful in maintaining farming in peri-urban areas.

N E Etim, J J Dukiya · International Journal of Advanced Remote Sensing and GIS · Nigeria (Abuja)

A study in the Kuje area council of Abuja, Nigeria, used questionnaires and multi-temporal satellite images from 1975–2010 to assess urban encroachment on agricultural lands. It found that urban encroachment into agricultural lands is occurring at an alarming rate of 15.7 km² annually, resulting in a total loss of 509 km² of agricultural land to urbanization over 35 years.

Sheila Castillo, Curtis R. Winkle, Stephen Krauss, Amalia Turkewitz, Cristina L.M. Silva, Edie Heinemann · Journal of Agriculture Food Systems and Community Development · United States (Chicago)

This study identifies seven perceived barriers to urban and peri-urban agriculture in the greater Chicago metropolitan area through interviews with urban planners and farmers. All seven barriers involve unclear or agriculture-unfriendly regulations. Results suggest that urban and peri-urban farmers are commonly forced to operate within a legal limbo or petition for exceptions to current regulations.

Shazia Iram, Ayesha Zaman, Zaiba Iqbal, Rabia Shabbir · Polish Journal of Environmental Studies · Global

This study screened soil samples from peri-urban agricultural areas to investigate heavy metal contamination and identify heavy metal-tolerant fungi. Results showed that the majority of isolated fungi were resistant to lead (Pb) and chromium (Cr). Among the strains, Aspergillus niger was the most tolerant to Pb with an MIC of 600 mg/l, and Aspergillus flavus was the most tolerant to Cr with an MIC of 400 mg/l.

Andrew Butt · Economic Papers A journal of applied economics and policy · Australia

This article reviews changes in farm output and structure in peri-urban regions around Australia's cities. It concludes that farming in these regions is changing differently from other agricultural regions, with productivity centered on a few high-value activities. The majority of peri-urban farming, while potentially providing landscape services, is unable to adjust to changing productivity regimes, creating vulnerabilities for these farming systems.

Tathagata Chatterji · South Asia Journal of South Asian Studies · India (Gurgaon)

A case study of Gurgaon, India, examined how local political factors, the rural-urban divide, and inter-governmental conflicts influenced the governance of a rapidly globalizing urban region. The study found that Gurgaon's real estate-driven transformation from a rural town to an outsourcing hub, involving the conversion of peri-urban agricultural land, has resulted in a fragmented landscape with glaring inequalities. This rapid urban makeover created everyday tensions and contradictions, particularly evident with the formation of a new municipal corporation.

Anushiya Shrestha, Rajesh Sada · · Nepal (Kathmandu)

Climate change and its impacts on peri-urban agriculture were investigated in four peri-urban villages in the Kathmandu valley, Nepal. Temperature showed an increasing trend, while rainfall was erratic with no distinct pattern. These changes primarily had negative impacts on agriculture, leading to increased crop pests and diseases and a decline in crop production.

CDR Aza-Gnandji, Yongxin Xu, Lincoln Raitt, Jonathan Levy · Water SA · South Africa (Cape Town)

This study explored the salinity of irrigation water from the Cape Flats aquifer in the Philippi farming area of Cape Town, South Africa, collecting water samples from boreholes and ponds in summer and winter. Concentrations of chloride, nitrate, potassium, and sodium exceeded target maximum limits set by DWAF and FAO guidelines. Groundwater and pond water were found to be brackish in most parts of the research area, with salinization primarily attributed to agricultural activities. The water is generally suitable for irrigation but requires caution for salt-sensitive vegetables.

K.G. Rosin, Ravinder Kaur, Sushma Singh, Prabhat Kumar Singh, Digvijay Dubey · Procedia Environmental Sciences · India

A study was conducted in peri-urban agricultural sites around Faridabad, Haryana, India, to assess groundwater contamination and the contribution of salt/trace metal-laden irrigation waters. Mean EC, Cl, and F concentrations in root zone leachates were found to be far beyond permissible limits, and some trace metals posed a threat to deep percolating waters. However, due to existing cropping patterns and deeper water table depths, the groundwaters were not yet vulnerable to these salts/trace metals, and the presence of salts in the groundwaters was primarily geogenic.

Doreen Atkinson · African Journal of Range and Forage Science · South Africa

This paper critiques the assertion that commercialization of smallholder agriculture poses dangers for sustainable rangeland management in South Africa. It argues that a range of policy options are required, including commercialization and subsistence farming, large-scale and smallholder farming, various land tenure options, rural and peri-urban farming, and part-time farming. The case of municipal commonage land is used to demonstrate the effectiveness of flexible policy options regarding land ownership, farming scale, and the social nature of farming, but it is noted that effective institutional development is a key requirement in all cases.

Shogo Mlozi · International NGO Journal · Tanzania

This paper assesses the knowledge of livestock keepers in Dar es Salaam, Tanzania, regarding the climate change effects of their activities. Over two-thirds of respondents did not believe solid waste, liquid waste, and pollution from livestock would affect future climate risks. However, they did perceive chemical pollution and land degradation from urban and peri-urban agriculture (UPA) livestock keeping as having climate change effects.