A new model of farming

> An innovative model

In order to develop the most environmentally friendly urban agriculture, the City has been working for several years with the AgroParisTech institute and INRA, which are developing a circular, ecological, productive and adapted cultivation method for soil-less cultivation in an urban environment.

It will be the first vertical greenhouse for diversified vegetable production, on a circular substrate and in a “low tech” operation.

Market garden production at the Cité Maraîchère will have no equivalent on the market.
Indeed, it will be the first:

  • Market garden production from Romainville.
  • Soil-less, circular, ecological*, socially responsible and operational market garden production.
  • Intensive production (1,000 m2 of cultivation) of market garden produce using this agronomic system.
  • Production on a circular substrate in greenhouses.
  • The Cité Maraîchère is therefore intended to be a laboratory for experimentation of soil-less agricultural techniques in urban areas.

* The “Organic Agriculture” certification can only apply to open-field production, it will therefore not be possible for the market garden production of the Cité Maraîchère.

Farming in growing trays © ilimelgo – Secousses

> Market gardening activity in growing trays

The production is carried out in growing trays on substrate.

The latter has been adapted to the cultivation of vegetable plants through a prior action research project on the substrates, the materials used and the irrigation system. This type of cultivation is currently implemented on many farms around the world, but the modalities vary widely from one farm to another (substrate materials, lighting or heating system, fertilization methods, etc.).

> A substrate made from 100% waste products

The objective of the Cité Maraîchère‘s agronomic project is to recreate a soil by reusing the city’s waste (wood waste, compost, coffee grounds, etc.) in a circular economy that does not require chemical fertilizers either. In fact, the philosophy is to cultivate in an ecological way, without synthetic chemicals (fertilizer or pesticide).

In France, faced with the emergence of urban agriculture, the AgroParisTech institute has begun research on the cultivation of “technosols” composed of urban waste, the T4P (Toit Parisien Productif Projet Pilote – Parisian Roof Productive Pilot Project) research project, in order to meet its demands for ease of implementation and its environmental (production on soil unsuitable for cultivation, for example) and economic (low investment, relatively low operating costs) challenges.

In 2017-2018, a research project that won a CASDAR (Compte d’Affectation Spéciale pour le Développement Agricole et Rural – Special Allocation Account for Agricultural and Rural Development) from the Ministry of Agriculture and Food, was based on the work of AgroParisTech and tested different types of substrates according to their composition (organic urban waste and construction waste) and their preparation (mixed or stacked). This study “Lifting the technological brakes on urban agriculture – Techn’AU”, carried out by the Astredhor Institute in partnership with AgroParisTech, Terreau Ciel, Paysan Urbain, Agricool and the City of Romainville, has made it possible to identify the optimal composition of the substrate for the Cité Maraîchère.

For the Cité Maraîchère project, particular attention was paid to the agronomic quality of the substrates. These will be used as supports for cultivation according to the principles of agroecology (crop associations, organic fertilization, etc.).

The City’s expectations with regard to the substrate are as follows:

  • Ensure sufficient yields.
  • To be light enough to be adapted to the expected bearing capacity of the vertical greenhouse floors.
  • Not to degrade too quickly to avoid having to renew the substrate too frequently (and reduce costs and handling).
  • Integrate recycled products from urban metabolism into its composition, particularly those from the Cité Maraîchère.

The thematic working group on agronomic techniques created by the City has been meeting since September 2018 to discuss, in particular, the composition of the substrate to be used in the Cité Maraîchère. A sub-group has committed to work more specifically on this point. Hence, an experiment was launched in April 2019 to test different mixes in greenhouses.

Conducted by the company Florentaise in partnership with AgroParisTech, Astredhor, Moulinot, UpCycle-La Boîte À Champignons and the City, the experiment compares a control substrate used in horticulture with 3 substrates composed of locally produced urban waste, including those to be produced at the Cité Maraîchère: vermicompost from food waste collected in Romainville (supplied by Moulinot), myceliumized coffee grounds, which is a mushroom cultivation waste produced in the Hauts-de-Seine (supplied by UpCycle-La Boîte À Champignons), crushed cellular concrete from construction waste from the Île-de-France region (supplied by Florentaise) and beer grain from breweries in the inner suburbs (supplied by Moulinot).

The experiment will be carried out over several cultivation cycles to test different species according to the seasons.

> An integrated and scalable cultivation system

The design of the Cité Maraîchère of Romainville has been optimized by integrating many parameters: load-bearing capacity, diffusion of light in the floors, integrated watering, etc.

The growing trays long rooted species (such as carrots) and some trays are arranged on two superimposed levels to increase the cultivation area.

Watering is done by drip or sprinkler depending on the type of crop, with a programmable system whose flow rate is adjustable according to the water requirements of the different planting areas.

Diagram of the cultivation in growing trays

> A varied, natural and seasonal production

In order to provide the residents with fresh and healthy products, to cultivate in an ecological way and to participate in raising the awareness of the population on environmental issues, the production of the Cité Maraîchère will respect strict specifications:

  • no synthetic chemical inputs.
  • seasonal production.
  • diversified crops.
  • common and ancient varieties, even tropical varieties if a demand emerges among the residents.

> Technical and scientific monitoring

Considering the innovative nature of the agronomic model, the cultivation is run in conjunction with the scientific and technical partners of the project through the thematic working group on agronomic techniques. The latter, which is composed of AgroParisTech, INRA, Astredhor, the Ministry of Agriculture, the Florentaise companies, UpCycle-La Boîte À Champignons and Moulinot, provides technical and scientific support through:

  • The monitoring and evaluation of agronomic systems, economic impacts (sales, distribution network, etc.), social impacts.
  • The analysis and consideration of studies and survey results.
  • The recognition of needs (jobs, training, etc.).

The cultivation or farm will be subject to quantitative and qualitative monitoring based on regular measurements and data collection. This data may be analyzed at meetings of the working group.

Finally, the results and data from the cultivation will be open and freely shared. According to the principles of open data, this information will be freely accessible and made available to any organization that requires it for research purposes.

This working group has been meeting approximately every quarter since September 26, 2018.

The Scientific Council meeting in June 2018