Agronomy Research Expertise in Montpellier and Languedoc-Roussillon (South of France)

Agronomy : crops and cropping systems

UPR  Recycling and risk

Member institutes and partners  : Cirad

The internal research unit (UPR) Environmental Risks of Recycling (CIRAD) develops solutions for recycling organic matter and waste using agricultural practices while controlling the agroenvironmental risks and making effective use of the cleansing potential of soil and plants. It addresses this issue by investing in research topics ranging from studies on biophysical organic matter and waste transfer and processing systems to the modelling and the integrated management of organic matter stocks and flows from the plot to the territory.

The UPR is based at several sites, with the main ones being in Montpellier (France) and Réunion. Studies are also conducted at other sites under collaboration agreements: (i) Aix-en-Provence (France) with the Centre Européen de Recherche et d’Enseignement des Géosciences de l’Environnement (two researchers), (ii) Rennes (France) with UMR Sol, Agro et hydrosystème Spatialisation (INRA, one researcher) and (iii) Hanoi (Vietnam) with the National Institute of Animal Husbandry (one researcher).

The UPR is organized along two main lines of scientific research:

  • Line 1. Management of aboveground and territorial residual organic waste (from workshop to territorial scales)
  • Line 2. Studies on residual waste-soil-crop interactions (from molecular to plot scales)

It is also supported by analytical and experimental platforms at each of the main sites.

The research topic ‘Modelling and analysis of mass flows on a territorial scale’ (Line 1) is focused on developing models to simulate agricultural production systems in which recycling has been used and to assess them in terms of sustainable development objectives, while taking two organization levels into account: farms (individual management) and organized groups of farms (collective management). The research topic ‘Interaction dynamics between residual organic waste, soil and crops’ (Line 2) is aimed at studying the dynamics of interactions of trace metals and nitrates with cropping systems and different types of soil on three different scales: regional, experimental plots and laboratory (rhizosphere and molecular).

In Réunion, the UPR is closely collaborating with local authorities and above all with the Région de La Réunion. In Montpellier, it has forged innovative partnerships with private companies, especially Phalippou Frayssinet, the leading organic fertilizer manufacturer in France.

Funding is mainly provided by the public sector and additional French national resources (Agence nationale de la recherche, ministries other than the Ministère de l’Enseignement supérieur et de la Recherche, Ministère de l’Outre-mer, Agence de l’Environnement et de la Maîtrise de l’Énergie). Funding associated with the unit’s research activities in Réunion is provided by the European Community and local authorities. Funding from the private sector and consulting missions also contributes to the unit’s financial balance.

Director: Jean-Marie Paillat

17  scientists

Unit website

List of research examples/projects for the resarch unit UPR  Recycling and risk on Agronomy: crops and cropping systems topics

Rhizosphere–a suitable scale for assessing the phytoavailability of trace elements?

In situ sampled (1.5-4 mm thick) durum wheat plant with soil attached to its roots, representing the rhizosphere. - © M.Bravin

Plants are key constituents of agroecosystems,so it is essential to study soil-plant transfers (phytoavailability) of trace elements (TE) in contaminated agricultural soils. Some TE such as arsenic (As) can accumulate in plants, with a high subsequent risk of contaminating the food chain. Other TE like copper (Cu) are mainly phytotoxic and affect crop yields. (...)

Integrated modelling of cropping practices and biomass flows in agricultural production systems

View of a cattle farm in the highland region of Réunion. - © J.M. Médoc

The ‘Mafate’ approach was developed for modelling and analysing mass flows on farm and territory scales, and designed to represent farmers’ practices and test management strategies. It involves four steps: (i) acquisition of knowledge on practices, (ii) their conceptual representation (action models, typologies), (iii) construction of simulation models, (iv) (...)

Managing nitrate pollution hazards in western Réunion

The population of the island of Réunion should increase by around 30% by 2030. Treatment of agroindustrial (effluents, composts, stillage, etc.) and urban (STEP sludge, waste water, mixed compost) organic waste will accelerate to overcome the structural delays. Moreover, in this island region, expansion of the urban fabric substantially hampers the development (...)

Environmental impact of composting

Turning compost windrows on the Plaine des Cafres, Réunion (photo: J. Lepetit, 2005)

Composting is an interesting technique for better spatiotemporal management of organic matter derived from livestock farming: reduction in mass and volume, enhanced soil fertility, and gradual plant nutrition. However, gas release accounts for some loss during organic matter transformation, sometimes representing as much as 50% of the composted organic matter. (...)


Update on 19/04/12


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