Research & reports

AN Asadu, EM Igbokwe, JM Chah, IA Enwelu · Journal of Agricultural Extension · Nigeria (Enugu)

This study investigated farmers' perceptions of health and environmental hazards from urban livestock keeping in Enugu Urban, Nigeria, interviewing 75 heads of households. While all respondents were aware of general health and environmental implications, only 4.0% knew livestock could cause climate change. Identified environmental issues included crop destruction (89.3%), urban filth (89.3%), and noise (88.0%), while health issues included disease spread (50.7%), accidents (46.7%), and bad smell (86.7%).

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.

Danfeng Huang · Journal of Changjiang Vegetables · Global

This paper discussed the importance of intensive vegetable production in urban agriculture, highlighting its role in guaranteeing the supply, quality, and safety of fresh vegetables. It summarized key aspects of intensive production, including industrialized seedling production, facility production, efficient cultivation, postharvest processing, and commercial management, but also presented environmental problems and restricting factors in the development of intensive vegetable production.

Patrick F. Banga · · Zimbabwe

Unsanctioned urban agricultural activities in Emakhandeni High Density Suburb of Bulawayo, Zimbabwe, negatively impact biodiversity. Researchers interviewed 100 people and conducted field visits, finding that the majority of cultivators operate outside existing laws and guidelines. This leads to progressive land degradation, massive deforestation, soil erosion, dried wetlands, lowered water table, and compromised groundwater quality due to pesticides and inorganic fertilizers.

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.

Sylvestre Dasylva · Journal of environmental science & engineering · Senegal (Dakar)

This paper discusses rainwater management in the "niayes" zone of Dakar, Senegal. This area is characterized by agricultural depressions with typically high groundwater levels, but a recent drop has turned some into runoff-gathering sites, used for urban agriculture among other services. However, two acute problems are observed: hydrological drying due to insufficient rainwater refill and urbanization of these bottom-lands. Furthermore, decreasing pluviometry exacerbates nuisances like floods and malaria.

Christophe Antonio‐Nkondjio, Billy Tene‐Fossog, Cyrille Ndo, Benjamin Menze Djantio, Serge Zebaze Togouet, Parfait Awono‐Ambene, Carlo Costantini, Charles S. Wondji, Hilary Ranson · Malaria Journal · Cameroon

This study assessed the influence of urban pollution and agriculture on malaria vector distribution and insecticide susceptibility in Douala and Yaoundé, Cameroon, from October 2009 to December 2010. Researchers sampled 1,546 anopheline larval breeding sites and analyzed water parameters. Findings showed mosquitoes from cultivated urban areas exhibited the highest insecticide resistance levels, with urban agriculture, rather than pollution, suggested as the major factor driving resistance.

FU Li-hua · 自然资源学报 · China (Shanghai)

A study of Shanghai, China, building an evaluation index system reflecting the characteristics of sustainable urban agricultural development, using a combination of the analytic hierarchy process (AHP) and the information entropy method to determine index weights, and applying it to time-series data from 1993 onward to produce a quantitative, comprehensive appraisal. The results comprise three findings. First, the population subsystem progressively became a main obstructive factor for sustainable urban agricultural development, the economic subsystem gradually became a main contributing factor, and the social subsystem grew more important in raising development capability, while cultivated land resources became increasingly scarce and continued to decrease, constraining improvement, and the heavy burden of agricultural production's self-pollution had a negative effect on the overall upgrade of development capability. Second, the resource (R-D) composite index was not high and declined significantly, averaging 1.9090 over 1993-2006 and falling 6.00% per year from 2.5336 in 1993 to 0.5541 in 2006, indicating growing resource pressure; the environmental (E-D) composite index was smaller and changed little, remaining around 1.0000 in most years, with environmental pressure staying high but stable. Third, after earlier wave-like fluctuations, the overall composite evaluation index entered a sustained, steady climb, with a significant increasing trend in development capability.

Anges Yadouléton, Alex Asidi, Rousseau F Djouaka, B. James, Christian Agossou, Martin Akogbéto · Malaria Journal · Benin

A study in urban areas of Benin investigated the impact of rapid vegetable farming development on the emergence of insecticide resistance in Anopheles gambiae populations, using sociological data, bioassay tests, and biochemical analysis. The expansion of urban agriculture led to improper insecticide use for vegetable pests, exerting strong selection pressure on mosquito larval populations. This resulted in the emergence of insecticide resistance in malaria vectors, with permethrin mortality rates of 76% in Parakou, 23.5% in Porto-Novo, and 17% in Cotonou.

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.

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.

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.

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.

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, 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.

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.