Research & reports

Mirelys Rodríguez Alfaro, Olegário Muñiz Ugarte, Bernardo Calero Martín, A. Álvarez, Francisco Martínez Rodríguez, Teudys Limeres Jiménez, Mercedes Orphee Montoya, Adriana M. de Aguilar Accioly · DOAJ (DOAJ: Directory of Open Access Journals) · Cuba

This study evaluated the heavy metal content of Cadmium, Lead, and Nickel in organic fertilizers (composts from urban solid waste) and substrates, and their effect on vegetables grown in organoponics in Havana and Guantánamo, Cuba. Composts obtained from unsorted urban solid waste and the substrates prepared from them were found to contain heavy metals, especially Cadmium and Lead, above maximum permissible limits. It was concluded that these products should not be used for food production, as these metals translocate to the edible parts of the cultivated vegetables.

L Ndiaye M, Y Dieng, S. Niang, Rak H, Mauro Tonolla, Raffaele Peduzzi · African Journal of Microbiology Research · Senegal (Dakar)

A survey in Dakar, Senegal, assessed the effect of irrigation water quality on Salmonella spp. incidence in lettuce. Microbiological analysis revealed that 35% of irrigation water was contaminated by Salmonella spp., with no significant difference between groundwater and wastewater. Lettuce from Dalifort and Grand-Yoff markets showed significantly higher contamination rates than those from Sham and Zinc markets. The study concluded that irrigation water and manure are potential sources of contamination, and lettuce may serve as a vector for pathogen transmission to consumers.

Hyuck-Soo Kim, Young‐Nam Kim, Jin‐Won Kim, Kye-Hoon Kim · 한국토양비료학회지 · South Korea (Seoul)

This study investigated the properties and total and phytoavailable contents of heavy metals (Cd, Pb, Cu, Zn) in 21 urban agricultural soils in Seoul, South Korea. The total heavy metal concentrations in the examined urban agricultural soils were found to be lower than the warning levels for area 1 according to the Soil Environmental Conservation Act of Korea. Phytoavailable-Cu, -Pb, and -Zn concentrations were also reported as 0.02-0.28, N.D-0.09, and 0.01-0.43 mg/kg, respectively.

Saad El‐Din Hassan, Eva Boon, Marc St‐Arnaud, Mohamed Hijri · Molecular Ecology · Canada

A study assessing indigenous arbuscular mycorrhizal fungi (AMF) community structure in roots and soil of Plantago major (plantain) growing on trace-metal (TM)-contaminated versus uncontaminated sites, selected based on a survey of TM concentrations (As, Cd, Cu, Pb, Sn, Zn) in community garden soils in Montreal, Canada. AMF community structure was analyzed using PCR-DGGE, cloning and sequencing, and direct sequencing. Native AMF diversity, measured by the number of AMF ribotypes, was decreased in TM-polluted soils and plant roots compared with unpolluted sites, and community structure was altered by TM contamination. Various Glomus species along with Scutellospora aurigloba and S. calospora were the most abundant ribotypes in unpolluted soil, while G. etunicatum, G. irregulare/G. intraradices and G. viscosum occurred in both polluted and unpolluted soils, and G. mosseae together with unidentified Glomus ribotypes (B9, B13) dominated in TM-polluted sites. The predominance of G. mosseae at metal-polluted sites is interpreted as suggesting tolerance to TM stress and potential use for phytoremediation.

Zhou Pei · · China (Shanghai)

A study conducted in Orchard Village, Nanhui District, Shanghai, from July to September 2009, investigated the effects of phosphorus non-point source pollution on groundwater in an urban agricultural region. Total phosphorus concentrations averaged 1.31 mg/L and phosphate concentrations averaged 0.42 mg/L, with phosphate significantly exceeding the V class surface water standard (0.4 mg/L), rendering the water unsuitable for drinking. Phosphorus non-point source transport was linked to land-use types, with phosphorus content near orchards changing with increased rainfall, and farmland phosphorus loss accelerating with runoff, fertilization, and water leach.

Mamadou Ndiaye, H.‐R. Pfeifer, S. Niang, Y Dieng, Mauro Tonolla, Raffaele Peduzzi · VertigO · Senegal (Dakar)

In Dakar's urban agriculture, untreated wastewater is used for irrigation due to shallow groundwater salinization. A study conducted at Pikine and Patte d'Oie sites evaluated the chemical and microbiological quality of irrigation water. Findings showed that total nitrogen in irrigation water exceeded WHO guideline values, Salmonella spp. was isolated from 35% of irrigation water, and a wastewater sample tested positive for Vibrio cholerae. This research indicates that irrigation with polluted water and the use of organic fertilizers can degrade groundwater quality and pose health risks.

Zhou Pei · · China (Shanghai)

A study from July to September 2009 in an orchard village, Nanhui District, Shanghai, investigated the characteristics of non-point source nitrogen pollution in groundwater. Total nitrogen and its three forms (NO3-N, NH4-N, NO2-N) were monitored, revealing NO3-N as the main form (average 1.43-13.71 mg/L). Nitrogen pollution in groundwater depended on land use, with NH4-N pollution most serious under residential areas (average 0.074-0.457 mg/L). Total nitrogen pollution near the river and orchard (average 33.67-62.57 mg/L and 33.05-65.04 mg/L) was more severe than under residential areas.

Xiaona Li · Nongye huanjing kexue xuebao · China

A study measuring dioxin-like compound (PCDD/Fs) concentrations in 23 surface soil samples collected from different areas of Baiyin City, China, using HRGC/HRMS (high-resolution gas chromatography/high-resolution mass spectrometry). The concentration range of 2,3,7,8-PCDD/Fs was 0.42-8.56 pg I-TEQ/g, averaging 2.28 pg I-TEQ/g. By land-use type, concentrations averaged 3.37 pg I-TEQ/g in industrial areas, 1.31 in urban areas, 1.01 in agricultural areas, and 0.85 in background areas, following the order industrial > urban > agricultural > background. Higher-chlorinated isomers were the dominant contributors to total toxic equivalency (TEQ) in most samples.

O. Muñiz, M. Ternero, Álvarez Montero, F. Martínez, T. Limeres, O. Jouber, M. Orphee, Julia Vidan Estevez, B. Calero, F. A. de Alcantara, Adriana María de Aguiar Accioly · Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) · Global

This paper situates its topic within the urban agriculture movement, which it describes as having successfully enabled low-input food production in cities, noting that organoponicos — plots focused on producing leafy vegetables and condiment crops in organic substrates — have driven up demand for organic material sources. The title indicates the study addresses the effect of using heavy-metal-contaminated compost on vegetable production, but the available abstract provides only this background context, with no results on contamination or crop impact stated.

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.

Y. A. Iyaka, SE Kakulu · African Research Review · Nigeria

This study determined the levels of copper (Cu) and zinc (Zn) in soil samples collected from cultivated farmlands near abandoned industrial sites in Minna and Bida, Niger State, Nigeria, using flame atomic absorption spectrophotometry. Concentrations ranged from 12-89 mg Cu kg-1 and 2.8-41 mg Zn kg-1 for Minna, and 2.4-6.5 mg Cu kg-1 and 0.57-36 mg Zn kg-1 for Bida. Apparent accumulation of Cu was found in Minna cultivated farmlands, with a mean Cu content of 24 ± 22 ppm, which was almost five times that of the control soils. Other mean values were similar to soil background averages.

J.N. Hogard, Julius N. Fobil, Godfred K. Ofosu-Budu, D. Carboo, Nii‐Ayi Ankrah, Alexander K. Nyarko · · Ghana

This study in Ghana investigated the macro-nutrient content and heavy metal concentrations in solid waste composts to assess their potential for soil fertility amelioration and health implications in urban and peri-urban agriculture. Overall NPK concentration was low, with agricultural waste composts showing higher total N, K, and organic carbon than municipal solid waste (MSW) composts. Heavy metal concentrations for Ni, Zn, Cu, and Cd were generally low and within Australian standards. However, lead (Pb) concentration in mixed MSW composts was significantly high during the dry season, exceeding the Australian limit of 150 mg/kg Pb for unrestricted use. Seasons and composting processes were found to be important determinants of toxic metal concentrations in final compost products.

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.

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.

F Ortega Sastriques, Rosa Orellana Gallego · Revista ciencias técnicas agropecuarias · Global

In many cities, potable water is expensive, and its availability is limited and will decrease in the future. Urban agriculture is an aspect to consider in this context.

F Ortega Sastriques, Rosa Orellana Gallego · · Global

Due to high prices and limited availability of drinking water in many cities, urban agriculture will require the use of alternative water sources. Groundwater and surface currents near cities are typically polluted, and this paper points out aspects to consider for safe irrigation using sewage water.

Astrid Mendez, Paulo Cseri Ricardo, P Jeny Pérez, Callejas Hernández, Osvaldo Campos · DOAJ (DOAJ: Directory of Open Access Journals) · Cuba

This introductory study in Arroyo Naranjo municipality, Cuba, examined the use of Luyanó effluent wastewater for irrigation in urban agriculture. The wastewater was classified as low contamination based on BOD5 and COD values and posed no toxic contamination risk to soil or environment. However, it should not be used without prior treatment for direct consumption crops due to its microbial load. Experimental plots with carrot, radish, and marigold showed high agricultural yields, and radish harvests had no bacterial contamination.

Halidou Koanda · Infoscience (Ecole Polytechnique Fédérale de Lausanne) · Sub-Saharan Africa

In Sub-Saharan Africa, faecal sludge management practices are often financially unviable due to widespread lack of municipal involvement, paucity of legal provisions, and absence of stakeholder coordination. This leads to indiscriminate dumping of faecal sludge in urban areas or its untreated use in urban agriculture. These practices pose permanent and serious health risks and contaminate scarce ground and surface water. This research aims to develop an innovative strategic planning approach for sustainable urban faecal sludge management to minimize public health and environmental risks.

B. Jankiewicz, B. Ptaszyński · Polish Journal of Environmental Studies · Poland

This study determined the levels of bioavailable and total chromium (III) and chromium (VI) in the soil of an allotment garden located in the center of Łódź, Poland. Chromium was measured using the spectrophotometric method and atomic absorption spectrometry. The research also examined the effects of iron and copper ions on the determination results.

R. B. Singh · IAHS-AISH publication · India

A study on wastewater management in 300 class-I cities and 23 metropolitan cities in India found that the total wastewater generated is approximately 158x10^8 l/day, with treatment capacity being only 375x10^7 l/day. In metropolitan cities, only 30% of wastewater is treated before disposal, and most cities only have primary treatment facilities. Untreated water is being used for urban agriculture, posing risks to public health and potential surface and groundwater pollution.

L.M. van den Berg · WIT transactions on ecology and the environment · Africa, Asia

Urban agriculture, despite severe competition for space, plays roles such as fresh food supply, leisure, supplementary income for the urban poor, and green space management. Case studies in Africa and Southeast Asia demonstrate the difficulty of maintaining these roles due to public health and environmental degradation concerns. Urban agricultural producers may rely on polluted streams for irrigation, cause soil erosion through inappropriate farming techniques, or poison surrounding residents with pesticides. The paper suggests that urban agriculture could be more beneficial to the urban system if treated by town planners as a normal urban function requiring both regulation and protection.

James R. Preer, Ahmed N. Abdi, Harkewal S. Sekhon, George B. Murchison · Journal of Environmental Science and Health Part A Environmental Science and Engineering and Toxicology · Global

This study investigated cadmium (Cd) and zinc (Zn) concentrations in vegetables grown in community gardens on different urban soils. Vegetables from a low-pH urban soil without contamination history showed higher Cd and Zn levels than those from a reclaimed landfill with digested sewage sludge, and also higher than a low-metal, neutral-pH site. Liming on the low-pH site reduced Cd and Zn concentrations in beet, lettuce, radish, and Swiss chard leaves, reaching background levels after four years. The findings indicate that soil pH is more important than total soil Cd and Zn in determining vegetable metal availability.