Research & reports

Abegunde A. A, Emmanuel Olufemi Omisore, O. F. Oluodo, D O Olaleye · African Journal of Agricultural Research · Nigeria (Lagos)

A study in the Eti-Osa local government area of Lagos, Nigeria, investigated the socio-spatial effects of urban horticultural gardens. Of 75 identified gardens, 63 managers were interviewed, revealing that 79.4% of gardens were profit-oriented. Gardens had inadequate setbacks (mean 1.45 m) from roads, leading to off-street parking and traffic congestion. Only 20% of horticulturists aimed to improve urban aesthetics, indicating a need for urban planners to educate them to prioritize urban aesthetics over economic gain.

Justin Stoler, John R. Weeks, Arthur Getis, Allan G. Hill · American Journal of Tropical Medicine and Hygiene · Ghana (Accra)

A 2003 study in Accra, Ghana, surveyed 3,164 women to examine the relationship between self-reported malaria and proximity to urban agriculture (UA). The odds of self-reported malaria were significantly higher for women living within 1 km of UA compared to those living near an irrigation source, with the association disappearing beyond this distance. Malaria prevalence was often elevated in communities within 1 km of UA, even with more favorable socioeconomic characteristics.

Stefan Dongus, Dickson Nyika, Khadija Kannady, Deo Mtasiwa, Hassan Mshinda, Laura Gosoniu, Axel Drescher, Ulrike Fillinger, Marcel Tanner, Gerry F. Killeen, Márcia C. Castro · Geospatial health · Tanzania (Dar es Salaam)

A cross-sectional survey in urban Dar es Salaam, Tanzania, investigated the influence of agricultural and geographical features on Anopheles larvae presence. The study found that agricultural areas, covering over 5% of the 16.8 km2 study area, had a 1.7 times higher proportion of habitats containing Anopheles larvae compared to other areas. However, breeding sites originating from urban agriculture accounted for less than a fifth of all malaria vector breeding sites in the city.

P. S. Datta, Shipra Tyagi · · India

Peri-urban agriculture in the Delhi-NCR area is highly dependent on groundwater availability amid rapid urbanization. This study integrates dynamic δ18O isotopic composition data on groundwater with static data such as elevation of recharge sites to delineate potential recharge zones and hydrodynamic aquifer zones. Significant δ18O-elevation relationships were found (r² = 0.808 to 0.982), with recharge-site elevation resolutions of about 20m in the northwest and 75m in the southwest, identifying potential recharge zones at elevations of 210-230m in the northwest and above 260m in the south. However, variation in groundwater isotopic composition over time indicates that the corresponding aquifers are relatively small and of low productivity, and points to the likely presence of many low-permeability zones in the northwestern recharge areas — a constraint on the groundwater resources that sustain peri-urban agriculture there.

Eveline Klinkenberg, Philip J. McCall, Michael D. Wilson, Felix P. Amerasinghe, Martin J. Donnelly · Malaria Journal · Ghana

This study investigated the impact of urban agriculture on malaria transmission risk in Accra, Ghana, through larval and adult mosquito surveys. It found that Anopheles spp. and Culex quinquefasciatus outdoor biting rates were three and four times higher, respectively, in areas around agricultural sites compared to areas far from agriculture. The annual Entomological Inoculation Rate (EIR) was also higher in agricultural areas (19.2) than non-agricultural areas (6.6), suggesting that urban agricultural areas may increase malaria transmission risk by providing resting sites for adult mosquitoes.

M. B. David · African Affairs · Kenya

This study on urban agriculture in the Kenyan town of Nakuru illustrates health and environmental problems associated with keeping livestock in urban areas, the small size of plots cultivated, and the dependence of urban households on rural sources of food. These findings were observed in the context of economic hardships occasioned by structural adjustment programmes since the 1980s.

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.

Shane R. de Solla, Pamela A. Martin · Environmental Toxicology and Chemistry · United States

Because many reptiles oviposit in soil within agricultural landscapes, this study evaluated the toxicity of two commonly used nitrogenous fertilizers — urea and ammonium nitrate — to snapping turtle (Chelydra serpentina) egg survivorship. Eggs were incubated, unmanipulated and under ambient conditions, in a community garden plot treated with urea at realistic rates up to 200 kg/ha in 2004 and ammonium nitrate up to 2,000 kg/ha in 2005, and separately in covered laboratory bins designed to minimize nitrogen loss through volatilization or leaching. In the field, neither urea nor ammonium nitrate affected hatching success or development, despite ammonium nitrate showing overt toxicity to native plants. In the laboratory, however, both fertilizer exposures reduced hatching success, lowered body mass at hatching, and reduced post-hatching survival compared with controls. The authors attribute the field's lack of toxicity to leaching and atmospheric loss of nitrogen in soil, and conclude that nitrogenous fertilizers likely have little direct impact on turtle eggs deposited in agricultural landscapes.

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.

Barbara Matthys, Penelope Vounatsou, Giovanna Raso, Andres B. Tschannen, EMMANUEL GBEDE BECKET, Laura Gosoniu, Guéladio Cissé, Marcel Tanner, ELIÉZER K. N’GORAN, Jürg Utzinger · American Journal of Tropical Medicine and Hygiene · Côte d'Ivoire

This study investigated malaria risk factors in urban farming communities in a medium-sized town in Côte d'Ivoire, conducting two cross-sectional surveys among 112 households across six agricultural zones. The overall prevalence of Plasmodium falciparum was 32.1%. Findings indicate that specific crop systems and agricultural practices may increase the risk of malaria in urban settings of tropical Africa.

Brian Halweil · · Global

This book points out that the long-distance food system consumes staggering amounts of fuel, generates greenhouse gases, and compromises food security. Since 1961, the tonnage of food shipped between nations has grown fourfold, with food in the United States typically traveling 1,500 to 2,500 miles from farm to plate. While this system often runs roughshod over local cuisines, varieties, and agriculture, a local-foods movement is beginning to emerge globally.

Kenny Lynch · · Indonesia (Jakarta)

This piece reviews the literature on urban agriculture (UA), noting that Bryceson (1993) provides documentary evidence from as early as 1939 of UA's importance during and after the Second World War, and that the UN University's Food Energy Nexus research programme in the mid-1980s prompted researchers to examine agricultural cultivation within city boundaries more seriously. Since then, a significant body of literature has developed around a central debate over whether urban agriculture is beneficial, summarized by Lynch (2002). This summary is described as having two problems: it assumes urban agriculture is a homogenous activity with universally similar impacts, and it is largely viewed from the perspective of a city's population, so urban agriculture tends to be seen as beneficial for food, employment and the environment with little consideration of its impacts on the rural-urban food supply. This led Lynch, Binns and Olofin (2001) to argue that urban agriculture should instead be considered part of the broader urban food supply system.

James M. Wolf, M S van Wijk, X Cheng, Yuanhao Hu, C.A. van Diepen, A.W. Jongbloed, H van Keulen, C H Lu, R.P. Roetter · Environment and Urbanization · China (Beijing)

This paper reviews agricultural production trends in Beijing Municipality and their impact on water quality. Rapid urbanization and agricultural intensification have led to concerns regarding water resource quantity and quality. The agricultural sector, while supplying food, is a major water user and has contributed to significant water supply-demand gaps and high levels of water pollution, particularly from intensive crop, vegetable, and livestock production.

Ausaf-ur Rahman, Mohammad Ait Kadi, Johan Rockström · Water Science & Technology · Global

A synthesis paper from a 2002 workshop reports that competing demand for water between agriculture and urban users is generating severe stress on water resources, with virtual water trade (importing food instead of pursuing self-sufficiency, to conserve real water resources) and water reuse (irrigation with treated urban wastewater) emerging as the two dominant proposed responses. It states that virtual water trade carries serious political and economic risks, with one proposed remedy being an international virtual water trading council.

E. Mensah, Philip Amoah, Pay Drechsel, Robert Clement Abaidoo · CABI Publishing eBooks · Sub-Saharan Africa

This work, presented as case studies from Accra and Kumasi, addresses environmental concerns of urban and peri-urban agriculture. It focuses on waste composting for urban and peri-urban agriculture, aiming to close the rural-urban nutrient cycle in Sub-Saharan Africa.

E. Mensah, Philip Amoah, Robert Clement Abaidoo, Pay Drechsel · CGSPace A Repository of Agricultural Research Outputs (Consultative Group for International Agricultural Research) · Ghana

This document presents case studies on environmental concerns related to urban and peri-urban vegetable production in Kumasi and Accra, Ghana. It is part of a larger work on waste composting for urban and peri-urban agriculture in Sub-Saharan Africa.

Fabio Bontadina, Pascale Contesse, Sandra Gloor · DORA WSL (Swiss Federal Institute for Forest, Snow and Landscape Research) · Switzerland (Zurich)

This study analyzed attitudes towards urban foxes in Switzerland using a nationwide survey and questionnaires for households and allotment gardeners in Zurich. While 60% of Swiss respondents were against urban foxes, only 40% in Zurich were; however, 70% of gardeners opposed them, with 55% reporting damage caused by foxes, which negatively correlated with fox acceptance.

Nicholas P. Dunning, Timothy Beach, David J. Rue · Ancient Mesoamerica · Guatemala

This study of the Petexbatun region, Guatemala, found that ancient Maya peoples in Preclassic times cleared large areas of upland tropical forest for agriculture, leading to significant soil erosion. During the Late Classic period, population expanded, forest clearance resumed, and upland agriculture, including terracing, was practiced, which significantly checked soil erosion. The study suggests considerable variation in urban agriculture among the region's major centers.

M. R. S. Mlozi · Development Southern Africa · Tanzania (Dar es Salaam)

This article discusses urban agriculture in Dar es Salaam, Tanzania, examining its role in helping residents cope with the country's economic crisis. The study also associates urban agriculture with environmental degradation in the city. Factors encouraging urban agriculture at four levels are identified, and concerted efforts at all four levels are suggested to mitigate further environmental degradation.