Research & reports

Nicola Silvestri, E. Bonari · CINECA IRIS Institutial research information system (University of Pisa) · Italy

Focusing on the area around Lake Massaciuccoli in Tuscany, Italy, this paper discusses the relationship between the management of peri-urban agricultural land — the transition zone between city and countryside — and the lake's eutrophication problem. It argues that proper management of the extensive agricultural areas within this heavily anthropized territory could contribute significantly to resolving the lake's eutrophication through management and structural interventions, while noting that partially reorganizing existing agricultural models carries both cost and difficulty.

Zhigang Wei · Journal of Qingdao Agricultural University · China

A comprehensive survey of agricultural structure and layout in Qingdao, China. It states the sector has achieved transformation and upgrading, with growing agricultural industrialization and increasingly optimized layout of agricultural areas approaching cluster-scale planting and breeding industries. However, it reports that further adjustment of planting structure faces major bottlenecks due to limits on arable land and food security: the traditional small-scale fish-farming model seriously restricts further development of animal husbandry and aquaculture, and fluctuating agricultural product markets combined with a lack of competitiveness are affecting the agricultural industry's layout. It concludes that crop structure needs further adjustment, that production should be scaled up, specialized and standardized, and that urban agriculture should be emphasized to expand agricultural functions.

Chandra Sen · Journal of Interdisciplinary Economics · India

This study estimated the impact of air pollution on crop yields in peri-urban areas of Varanasi, India. Phytotoxic gases are known to cause major yield reductions in important crops in developing countries, and in this study all major crops grown in peri-urban Varanasi — paddy, pigeon pea, maize, wheat, and potato — showed yield reductions attributable to air pollution. Air pollution was found to reduce both the yield and the nutritional quality of the produce, and the study calls for similar validation studies in other cities and for efforts to reduce air pollution in the city to improve crop yield and quality.

Karin Ahrné, Jan Bengtsson, Thomas Elmqvist · PLoS ONE · Sweden (Stockholm)

This study investigated bumble bees in allotment gardens along an urbanization gradient from inner Stockholm to rural areas. Findings showed that bumble bee diversity decreased with increasing urbanization, from approximately eight species in rural areas to five to six species in urban allotment gardens. Higher variability in the abundance of certain species in the most urban areas suggested a potentially weaker reliability of the pollination ecosystem service in areas strongly influenced by human activity.

Rodrigue V.C. Diogo, Andreas Buerkert, Eva Schlecht · Nutrient Cycling in Agroecosystems · Niger (Niamey)

This 24-month study investigated nutrient efficiency and food safety in urban and peri-urban agriculture in Niamey, Niger. Nutrient inputs and offtakes were quantified for 10 vegetable gardens and 9 millet fields, and contamination of irrigation water and selected vegetables with fecal pathogens and heavy metals was determined. Above-threshold levels of Salmonella spp. and Escherichia coli were detected in lettuce irrigated with river water and fertilized with animal manure, and in lettuce irrigated with wastewater, indicating food safety concerns.

Andreas Buerkert, Eva Schlecht, Martina Předotová, Rodrigue V.C. Diogo, Katja Kehlenbeck, Jens Gebauer · eScholarship (California Digital Library) · Sub-Saharan Africa

This study analyzed urban and peri-urban agriculture (UPA) systems in major Sub-Saharan African cities, measuring carbon, nitrogen, phosphorus, and potassium fluxes and conducting biodiversity studies. In Niamey, low-input gardens showed annual gaseous carbon emissions of 20-25 t ha-1, predominantly CO2, and high-input gardens irrigated with wastewater had annual CO2-C emissions of 27 t ha-1, with N2O as a major nitrogen loss contributor. Animal manure stored in the open was subject to large carbon and nitrogen losses, indicating environmental tradeoffs. However, UPA gardens in Niamey maintained a large variety of fruit and vegetable species, with richness increasing with garden and household size and commercialization.

Shahzad Kouser, Mr. Abedullah, Abdus Samie · The Pakistan Development Review · Pakistan (Faisalabad)

This study, conducted in 2006 with 200 farmers in two peri-urban villages of Faisalabad, Pakistan, estimated the economic values of negative health externalities from wastewater use in cauliflower production. While wastewater use appeared profitable without considering externalities, factoring in health costs strongly discouraged its use. The health externalities for a three-month cauliflower crop on 741 acres amounted to Rs 3.2 million, and for 5,283 acres of vegetables cultivated with wastewater in Faisalabad, the annual total was Rs 90.7 million. The findings indicate a significant economic loss due to wastewater use, suggesting that installing a water treatment plant is a viable option to minimize these external effects.

Lucette Laurens · Journal for Geography · France

This inquiry examines peri-urban agricultural spaces in Languedoc-Roussillon and the Montpellier agglomeration, France, which are characterized by a decline in agricultural activities and abandonment. These spaces are confronted with new, uncertain, and innovative dynamics, appearing as multifunctional spaces that need to be re-invented. The study highlights the paradox of these areas caught between appropriation for different uses and agricultural decline.

Shazia Iram, Iftikhar Ahmad, Doris Stüben · Pakistan Journal of Botany · Asia

Soil samples were collected from peri-urban agricultural land in Lahore, Pakistan, irrigated by industrial and sewerage waste from the Hudiara drain, and from mine waste soil in Wiesloch, Germany, and analyzed for heavy metals by X-ray fluorescence and ICP-MS and for fungal diversity and frequency by a soil dilution method. X-ray fluorescence found higher Zn, As and Pb in the German mine waste soil, and the more sensitive ICP-MS found higher Fe, Mn, Cu, As, Sr, Mo, Cd, Sb, Ti, Zn and Pb there as well; the Pakistani peri-urban soils had lower heavy metal concentrations than the German mine waste but higher overall fungal frequency and diversity. Testing radial growth of isolated Aspergillus niger, A. flavus and A. nodulans against CdCl2, CuSO4, NiCl2 and ZnCl2 at 1-40 ppm, all tested fungi tolerated ZnCl2 (25 ppm) and NiCl2 (12 ppm) but none tolerated CdCl2 or CuSO4.

Sophie Graefe, Eva Schlecht, Andreas Buerkert · Outlook on Agriculture · Niger (Niamey)

Semi-structured interviews with 130 households in Niamey, Niger, characterized urban and peri-urban agriculture (UPA) and assessed resource use. The study found high use of livestock manure and indiscriminate use of nutrient-loaded wastewater for irrigation, leading to significant nutrient surpluses in UPA gardens. Initial calculations suggested large gaseous emissions of nitrogenous compounds and and leaching of nitrogen, phosphorus, and potassium to groundwater.

Erastus K. Kang’ethe, Delia Grace, Thomas F. Randolph · East African Medical Journal · East Africa

This study synthesizes current knowledge on urban agriculture (UA) in East Africa, focusing on its human health impact. It identifies UA as an important source of food security, but notes that many zoonotic and food-borne diseases are associated with it, with a lack of evidence on human health impact and management. Major constraints include illegality and limited access to inputs and markets, indicating a need for more research to understand both positive and negative health impacts.

Bernard Keraita, Pay Drechsel, Flemming Konradsen · Water Science & Technology · Ghana (Kumasi)

A study in Kumasi, Ghana, assessed the use of on-farm ponds to reduce microbial contamination in wastewater-contaminated irrigation water, analyzing over 300 samples. It found that while ponds are common, their potential for pathogen removal via sedimentation is not fully optimized. Helminth eggs reduced by about 70% with careful water collection, but thermotolerant coliforms took six days in the dry season to meet WHO guidelines, indicating suboptimal performance for some pathogens.

Pay Drechsel, Olufunke Cofie, R. van Veenhuizen, Theophilus O. Larbi · Irrigation and Drainage · West Africa

Informal irrigation in urban and peri-urban agriculture (UPA) in West Africa offers benefits but is often hindered by water pollution, threatening public health. A multi-stakeholder process implemented since 2005 in six West African cities, including Accra, Ghana, aimed to integrate UPA into sustainable urban development. However, an internal lesson learned was that local partners may not prioritize every project, and capacity-building efforts might not provide expected incentives for commitment.

Euis Suryaningsih · Jurnal Hortikultura · Indonesia (Bandung)

From January to July 2001, a field experiment on vegetable disease control in a mosaic farming system in periurban agriculture was conducted at a farmer's field in Rancaekek, Bandung, Indonesia. Treatments included white plastic net cages, biorational pesticides, Bacillus subtilis, a mixture of Mancozeb and Bacillus subtilis, and an unsprayed control. All tested alternative control methods were very effective against major diseases of chili pepper, shallot, eggplant, beans, and cucumber, but the use of poisonous synthetic pesticides in periurban agriculture increases the likelihood of contaminating humans and the environment.

XU Yong-xian, Biao Huang · Soils · China

A study of a small-scale vegetable farming system in peri-urban Nanjing, China, monitored heavy metal balances and pollution potential from July 2003 to July 2004. Heavy metals entered the soil mainly through fertilization and irrigation, with organic manure application accounting for more than 98% of inputs. Annual heavy metal input in the area was significantly higher than in European farmland, while annual output was very low, under 10% of input, leading to accumulation of heavy metals in the plots; long-term vegetable cultivation had already caused heavy metal buildup in the soils. Copper, lead, zinc, and cadmium concentrations in vegetables and soil were still below national safety standard limits, so the vegetable farming system was assessed as currently safe. However, an evaluation that incorporated atmospheric deposition showed the region carries a high risk of copper, zinc, and cadmium contamination, and the study concludes that intensive vegetable cultivation will aggravate soil heavy metal pollution, potentially pushing the soil to Second Grade of the National Soil Environment Quality Standard within several decades.

Do Thuy Trang, Kåre Mølbak, Phung Dac Cam, Anders Dalsgaard · Tropical Medicine & International Health · Vietnam (Hanoi)

A cross-sectional study in a peri-urban area of Hanoi, Vietnam, surveyed 400 agricultural households and examined 807 stool samples from 620 adults and 187 children for helminth infections. The study found that 39% of samples were infected with helminths, with Ascaris sp. at 21.6%, Trichuris sp. at 9.8%, and hookworm at 21.8%. Wastewater exposure was not a major risk, but lack of sanitation facilities and use of fresh or inadequately composted human excreta in agriculture were important risk factors for infection.

Alex Thornton, Etienne Nel · Africanus Journal of Development Studies · South Africa (Peddie)

This study investigated the significance of urban and peri-urban agriculture (UPA) as a livelihoods strategy in Peddie, Eastern Cape province, South Africa, based on a PhD study. The findings indicate that UPA is not as significant or widely practiced as often assumed, despite its potential to address food insecurity and generate income. Its development has been slowed by various structural historical and socioeconomic barriers, limiting its current impact.

Viola Devasirvatham, P. S. Cornish · International Journal of Water · Australia

Peri-urban horticulture in Australia requires irrigation for year-round vegetable production. Subsurface Drip Irrigation (SDI) offers higher water use efficiency and crop yields, with the potential to reduce environmental risks from drainage and runoff. However, SDI has potential disadvantages, including poor germination or crop establishment and uneven wetting patterns. Research is needed to solve these problems and enable environmentally acceptable vegetable production.

이민수, 박덕병, 황대용 · 농어촌관광연구 · South Korea

A cost-benefit analysis of Sunchang County's 2007 pilot "allotment garden with log house" program (family farm-stay plots), launched by South Korea's Rural Development Administration in JeonBuk Province, using the county's internal records and interviews with project managers. The analysis found the program to be an inefficient business with a weak cost-benefit structure that produced a negative net benefit: at an assumed 6.5% discount rate, net present value was estimated at -262 million won, with a benefit-cost ratio of 0.70 and an internal rate of return of 2.7%. The authors nonetheless conclude the program is worth maintaining as part of the government's balanced regional development policy.

Mure Agbonlahor, S. Momoh, A. O. Dipeolu · International Journal of Vegetable Science · Africa

A sample survey of 242 urban vegetable farmers conducted through March 2006 examined production efficiency and its determinants in fadama agriculture — flood-plain cropping of short-duration crops on low-lying, seasonally flooded land — in urban southwestern Nigeria, using a stochastic frontier model. Mean farm size was 0.54 hectares and mean producer age was 42.6 years, while mean technical efficiency was only 74.36%, with the main sources of inefficiency identified as labor employment and the use of land and seed/cultivar resources; the most common crop combination was Telfaria occidentale, Amaranthus hybridus and Zea mays.

Stephanie Buechler, Gayathri Devi Mekala, B. Keraita · Victoria University Research Repository (Victoria University) · Global

This 2006 global study from Victoria University discusses wastewater use in urban and peri-urban agriculture for crop production and aquaculture, noting its role in generating livelihoods and providing cheap produce. However, the study emphasizes that clear policy guidelines and careful research are needed to prevent potential negative impacts on human health and the environment from wastewater reuse.

Adolphe Monkiédjé, Michael Spiteller, D. Fotio, Premasis Sukul · Journal of Environmental Quality · Cameroon (Yaounde)

This study evaluated the effect of different land uses on soil health indicators in peri-urban agricultural areas of Yaounde, Cameroon, by comparing five tilled sites with native forest land. While most cropped land showed higher levels of many soil health indicators, cultivation of crops like corn and sugarcane significantly impacted native soil quality. Specifically, phenol oxidase, microbial biomass C/organic C, and microbial biomass C/microbial biomass P were negatively affected, indicating negative management impacts on soil health.

Paule Moustier, George Danso · Agritrop (Cirad) · Global

This report discusses urban agriculture's role in addressing social, economic, and environmental challenges of rapid urban growth in developing countries. It notes that while urban agriculture attracts attention, its viability and need for political support remain debated. The report highlights arguments against targeting scarce public resources towards urban agriculture, citing high land costs in urban areas and insufficient evidence of its economic viability.

Samuel Martín, Nathalie Bertrand, Nicole Rousier · Géographie Économie Société · France (Rhône-Alpes)

This paper examines spatial planning documents in two Rhône-Alpes city regions, France, as a tool for regulating land use conflicts in peri-urban agricultural areas under urbanization pressure. The analysis highlights rising tensions between local actors and suggests that agriculture is instrumentalized by spatial planning policies at the inter-communal level. At the communal level, local plans manage neighborhood and land ownership conflicts.

Y. Arocha, B. Piñol, B. Picornell, R. Almeida, P. Jones, E. Boa · Plant Pathology · Cuba

A 2005 survey in the 'Alamar' organoponic in Havana province, Cuba, observed typical phytoplasma-symptoms of little leaf and witches' broom in all basil (Ocimum basilicum) plants. DNA analysis of leaf samples from 27 symptomatic plants confirmed an association with a 16SrI group phytoplasma (Aster Yellows; 'Candidatus Phytoplasma asteris'). This report from Cuba is the first record of this new disease, for which the name basil little leaf is proposed.