Case studies France
Management of metallic soil pollution in the urban allotment gardens of Nantes
- Phytoremediation experimentation (Juin2013)
The emerging concept of sustainable city encourages the expansion of allotment urban gardens. However, gardens may have been developed on areas where soil quality was not taken into account in urban planning. Attentive to the potential health risks associated with consumption of vegetables growing on contaminated soils, the city of Nantes has launched a program to assess the soil quality of its 24 collective gardens (one thousand plots) towards organic contaminants and trace elements and joined the french national research program JASSUR (ANR) on urban allotment gardens (2013-2016). The specific research objectives of the scientific teams in Nantes are : i) characterisation of soils (global parameters and contamination); ii) origin of contamination (geogenic, anthropogenic); iii) mapping of trace metals contents in soils; iv) evaluation of translocation from soils to vegetables; v) biophytoremediation processes development; vi) advising local authorities for making-decisions and soil management. Such a methodology has been/is currently developed for 5 allotment gardens.
Management of metallic soil pollution in the urban allotment gardens of Nantes
The emerging concept of sustainable city encourages the expansion of allotment urban gardens. However, gardens may have been developed on areas where soil quality was not taken into account in urban planning. Attentive to the potential health risks associated with consumption of vegetables growing on contaminated soils, the city of Nantes has launched a program to assess the soil quality of its 24 collective gardens (one thousand plots) towards organic contaminants and trace elements and joined the french national research program JASSUR (ANR) on urban allotment gardens (2013-2016). The specific research objectives of the scientific teams in Nantes are : i) characterisation of soils (global parameters and contamination); ii) origin of contamination (geogenic, anthropogenic); iii) mapping of trace metals contents in soils; iv) evaluation of translocation from soils to vegetables; v) biophytoremediation processes development; vi) advising local authorities for making-decisions and soil management. Such a methodology has been/is currently developed for 5 allotment gardens.
Food function and cropping practices of gardeners in urban allotment gardens of Paris and Montreal
This PhD is under the joint supervision of the University of Quebec in Montreal and AgroParisTech. It’s part of the French research program “Jassur” (“Urban associative gardens”) that began in 2013.
Montreal
In Montreal, in 2012, there were 95 community gardens and 77 collective gardens, which covered around 27 hectares[1]. The City program for community gardens was born in 1975. First centralized, it then became a responsibility of each district after the creation of the unified city of Montreal that merged the Island of Montreal and 27 surroundings municipalities in 2002. The heritage of this centralized program is visible in the size of the plots, the layout of the gardens and the rules that apply to the gardens, which are more or less the same all over the Island of Montreal: all plots in community gardens are between 15 to 18 m².
Collective gardens were born more recently and were initially dedicated to offer another option than donating food to fight food insecurity. As participants usually garden under the coordination of a garden supervisor, we did not include collective gardens in our study.
Paris and the “petite couronne” (surroundings districts)
In the Ile-de-France region (region of Paris), there is a long tradition of urban gardening: the heritage of the 19th century “workers’ garden” is significant, and the renewed interest for urban agriculture led to the appearance of a new form of associative garden inspired by New York community gardens: “shared gardens”.
Parisian gardens show a huge variability in their modes of organization (individual vs communal plots, size of the plots), denomination[2] and status. For example, in Paris region, plot sizes can range from 2m² to 500m².
In Paris itself, there were five “shared gardens” in 2003, they now are 131, chiefly localized in the eastern and southern boroughs of the city that used to be the industrial boroughs (which means more available spaces when industries left Paris) and were traditionally more popular, even if some of these boroughs experienced forms of gentrification. Most gardens within Paris belong to a municipal program called « Main Verte ». This program was created in 2003 by the City of Paris to deal with the increasing demand for garden plots and to provide them an institutional frame and common rules.
After a great decrease during the sixties and seventies, family gardens have been achieving a renewed interest from the end of the XXth century, both in terms of how they are considered by citizens and decision-makers and in figures. In the Ile-de-France region, most of these family gardens are affiliated to the National Federation of Collective and Family Gardens (FNJFC). Their exact number and area they cover is still poorly known. A spatial inventory is in progress to give a more accurate view of the extent of associative gardens in the region; first results show that urban associative gardens, all together, cover more than 900 ha in the Parisian region.
Research focus
Associative gardens fulfill a high diversity of function (Duchemin & Wegmuller 2010). Their social and recreational functions are well known, but their food function remains unknown and little information is available on gardeners’ cropping practices or the quantity and use of harvests. Meanwhile, associative gardens have the specificity to be located in urban environments that can bring contaminants to the gardens and to their products. Therefore, our research was oriented to answer these three questions:
- What are the gardeners’ production strategies and their determinants?
- How important is the food function of associative gardens according to gardeners (in relation to other functions)?
- Can gardeners’ assessment of soil sanitary quality lead to adaptations of their practices?
Research objectives:
- Identify the functions of associative gardens according to gardeners, their hierarchy and the importance of food function
- Evaluate quantitatively and qualitatively the food production of the gardens (amount of food produced, destination and use of products, reasons for growing these crops)
- Investigate gardeners’ cropping practices and their determinants to describe and evaluate their cropping systems
- Understand how gardeners consider or evaluate potential contamination of their garden (especially regarding their soil)
[1] In Montreal, there are two main types of associative gardens: collective gardens and community gardens. “Collective gardening is distinguished from community gardening by the fact that it is practiced by groups of people who grow a vegetable garden together instead of each person tending their own individual plot. Collective gardens involve the pooling of many small garden plots, with all participants assuming joint responsibility [usually under the coordination of a garden supervisor.] Community gardens, on the other hand, are administered by the Ville de Montréal and offer plots to individuals who grow and reap their own harvest. (http://www.centraide-mtl.org/en/stories/the-collective-gardens/)
[2] In Paris, many different names exist: jardins partagés, jardins d’insertion, jardins collectifs, jardins solidaires… The name that the group of gardeners has chosen to refer to their garden is meaningful, but it doesn’t refer to a fixed category. However, to simplify, we will distinguish to main category of gardens in the Parisian region: shared gardens are mostly located within the city of Paris, and are dedicated to be grown by a group of citizens, most of times, people that live in the very close neighborhood. The plots can be grown communally or be individual plots; and family gardens, which are the successors the 19th century-born « workers garden ».