The potential of urban agriculture in combination with organic waste valorization: Assessment of resource flows and emissions for two european cities

Waste management has become pertinent in urban regions, along with rapid population growth. The current ways of managing waste, such as refuse collection and recycling, are failing to minimise waste in cities. With urban populations growing worldwide, there is the challenge of increased pressure to import food from rural areas. Urban agriculture not only presents an opportunity to explore other means of sustainable food production, but for managing organic waste in cities. However, this opportunity is not taken advantage of. Besides, there is a challenge of mixed reactions from urban planners and policymakers concerning the challenges and benefits presented by using organic waste in urban agriculture. The current paper explores the perceived challenges and opportunities for organic waste utilisation and management through urban agriculture in the Durban South Basin in eThekwini Municipality in KwaZulu-Natal (KZN) Province of South Africa. It is anticipated that this information will be of use to the eThekwini Municipality, policymakers, researchers, urban agriculture initiatives, households and relevant stakeholders in the study areas and similar contexts globally. Two hundred (200) households involved in any urban farming activity and ten (10) key informants (six (6) staff from the Cleaning and Solid Waste Unit of the eThekwini Municipality and four (4) from the urban agricultural initiative) were selected using convenient sampling. Descriptive statistics and inductive thematic analysis were used to analyse data. The significant perceived challenges and risks associated with the utilisation of organic waste through urban agriculture included lack of a supporting policy, climatic variation, lack of land tenure rights, soil contamination and food safety concerns. Qualitative data further showed that the difficulty in segregating waste, water scarcity, difficulty in accessing inputs, limited transportation of organic waste, inadequate handling and treatment of organic waste, and being a health hazard were some important challenges. On the other hand, the significant perceived benefits associated with the utilisation of organic waste through urban agriculture were enhanced food and nutrition security, and opportunities for business incubation. Other important benefits established through qualitative data were an improved market expansion for farmers and improved productivity. Overall, despite the perceived challenges and risks, there is an opportunity to manage organic waste through urban agriculture. It is imperative for an integrated policy encompassing the food, climate and waste management to be developed to support this strategy. All stakeholders—the government, municipal authorities and urban agricultural initiatives should also, guided by the policy, support urban farmers, for example, through pieces of training on how to properly manage and recycle organic waste, land distribution, inputs availability and water usage rights among other things.

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Rearing substrate impacts growth and macronutrient composition of Hermetia illucens (L.) (Diptera: Stratiomyidae) larvae produced at an industrial scale

Scientific Reports ◽

10.1038/s41598-020-76571-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Andrea Scala ◽

Jonathan A. Cammack ◽

Rosanna Salvia ◽

Carmen Scieuzo ◽

Antonio Franco ◽

...

Keyword(s):

Organic Waste ◽

Fruits And Vegetables ◽

Industrial Applications ◽

Biodiesel Production ◽

Industrial Scale ◽

Waste Valorization ◽

Black Soldier Fly ◽

Hermetia Illucens ◽

Wide Range ◽

Spent Grain

Abstract Organic waste is a rapidly increasing problem due to the growth of the agricultural production needed to meet global food demands. Development of sustainable waste management solutions is essential. Black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) (BSF), larvae are voracious consumers of a wide range of organic materials ranging from fruits and vegetables to animal remains, and manure. Thanks to this ability and considering the larval high protein and lipid content, BSF larvae are a useful additive in animal feeds and biodiesel production. Unfortunately, the feasibility of using the black soldier fly as a tool for waste valorization and feed production has primarily been investigated at the benchtop scale. Thus, mobilization of current practices to an industrial scale is challenging because scaling up from small laboratory studies to large industrial studies is not necessarily linear. The goal of this study was to demonstrate the ability of the BSF to recycle organic waste at an industrial scale. To accomplish this goal, three organic waste streams were used (e.g., apples, bananas, and spent grain from a brewery) to test six diet treatments (1) apple, (2) banana, (3) spent grain, (4) apple and banana, (5) apple and spent grain, and (6) banana and spent grain. Working at scale of 10,000 BSF larvae life history traits, waste valorization, protein and lipid profiles were measured for each diet treatment. Differences were recorded across all variables, except substrate conversion, for larvae fed on fruit and spent grain (alone or with fruit). Growth rate significantly differed across treatments; larvae reared on spent grain grew twice as fast as those fed apples alone, but those reared on the apple and spent grain mixture produced twice as much insect biomass. However, it should be noted that larvae resulting from the apple diet contained 50% more fat than larvae fed the fruit and spent grain mixtures. Commonly-available organic wastes were successfully used at an industrial scale to produce BSF larvae that have the potential to substitute other sources of protein and lipids in different industrial applications. Industrialization efforts are encouraged to assess these impacts when integrating diverse ingredients into larval diets as a means to more precisely predict output, such as larval development time and final larval biomass.

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Sociodemographic, Cultural, Environmental and Agroecological Characterization in order to Adopt Urban Agriculture in the Municipality of Tuluá, Colombia

WSEAS TRANSACTIONS ON ENVIRONMENT AND DEVELOPMENT ◽

10.37394/232015.2020.16.8 ◽

2020 ◽

Vol 16 ◽

Keyword(s):

Sustainable Development ◽

Urban Agriculture ◽

Agricultural Production ◽

Organic Waste ◽

Management Practices ◽

Diversity Index ◽

Study Population ◽

The City

Some communities have moved from the countryside to the city for different reasons, sometimes they have managed to settle in slums and some people go to agricultural production inside the city for their support, by means of a knowledge they bring from the countryside, seeking a place offering them useful resources to produce food, in this sense, urban agriculture as an alternative livelihood and occupation, has a symbolic value, since it is a survival strategy for families [3]. For this reason, this study was carried out within the macro project “Implementación del proyecto educativo comunitario salud alimentaria y productiva en el desarrollo sustentable de la invasión de la carrilera, corregimiento Campoalegre del municipio de Tuluá” (translated: “Implementation of the community educational project, food and productive health in the sustainable development of the invasion community La Carrilera, Campoalegre district of the municipality of Tuluá”), of the Health, Care and Society research groups; GIUR and Agricultural Production, which supported the characterization of the sociodemographic, cultural, environmental and agroecological components in the community of “La Carrilera” that aimed to evaluate and to identify the problems and needs of the study population, through the implementation of surveys, measurement of the biological quality of water based on the methodology used by IDEAM, Roldán and Shannon-Weaver, and the characterization of organic solid waste where the method defined by Marmolejo was implemented, resulting in the identification of the different social groups that make up the community, the occupation of women, the economic income of families, among others. In addition, the high levels of water pollution were manifested with a diversity index of 0.83, indicating the low diversity in the tributary of the community, also the BMWP index presented that the quality of the waters is critical and doubtful, and finally obtained an organic waste production of 60.1% identifying that mainly fruit and vegetable waste is produced. Subsequently, from the diagnosis obtained, some intervention strategies were determined for the conservation of the water resource and sustainable management practices for the use and transformation of organic waste in the study population, which allows adopting urban agriculture and contributing to sustainable development of the sector in the municipality of Tuluá, Valle del Cauca.

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Mapping urban agriculture in Portugal: Lessons from practice and their relevance for European post-crisis contexts

Moravian Geographical Reports ◽

10.1515/mgr-2017-0013 ◽

2017 ◽

Vol 25 (3) ◽

pp. 139-153 ◽

Cited By ~ 4

Author(s):

Cecília Delgado

Keyword(s):

Urban Agriculture ◽

Social Economy ◽

Food Chains ◽

Allotment Gardens ◽

European Cities ◽

Simple Processing ◽

Training Activities ◽

Multi Level ◽

And Training ◽

Level Analysis

Abstract A significant sample of twenty-nine Portuguese urban agriculture (UA) initiatives is analysed in this article. It argues that emerging initiatives are relevant for shifting from a post-crisis approach to one that is more developmental. This multi-level analysis finds that UA in Portugal: embraces allotment gardens, urban farms and short food chains; deals primarily with vegetables and fruit; takes place predominantly on public and institutional land; and is championed by municipalities and to a lesser extent by civil society initiatives. UA is predominantly a metropolitan phenomenon. Furthermore, activities are organised around three pillars: production of food; simple processing and distribution; and a significant set of capacity building and training activities. UA is recent phenomena in Portugal, and it has expanded quickly since the 2008 economic crisis. The paper explores in-depth four innovative short food chains from the sample of initiatives. They are led by young entrepreneurs, make positive use of social networks, are committed to social and economic values, and expanded successfully in generating jobs at the time of the crisis. These examples strongly suggest that UA social economy enterprises are a driving force behind integrated sustainable development approaches in European cities, if and when supported by public policies.

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