Research & reports

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.

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.

QI Airon · · China

A study of Xi'an, China, built indicators for urbanization and urban agriculture development and applied principal component analysis and correlation analysis to examine their interaction mechanism and quantitative coupling relationship. Urbanization was found to promote urban agriculture's commercialization and scale through market effects and information diffusion, but rapid urbanization's rising population and industrial land use also strained land and water resources and degraded soil and the urban ecological environment, constraining urban agricultural development.

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.

Zikrullah Safi, Martina Předotová, Eva Schlecht, Andreas Buerkert · Journal of Plant Nutrition and Soil Science · Afghanistan (Kabul)

A two-year study in Kabul, Afghanistan, measured horizontal flows of C, N, P, and K, and leaching losses of N and P in 21 vegetable gardens, 18 cereal fields, and vineyards. The findings suggest that soils in extensive cereal fields are at risk of N and K depletion, vegetable gardens face K depletion, and vineyards may be oversupplied with nutrients, potentially contributing to groundwater contamination. These results merit verification.

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.

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.

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.

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.

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.