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

Agronomy : crops and cropping systems

UMR Eco&Sols Functional Ecology & Biochemistry of Soils & Agroecosystems (in French)

Member institutes and partners  : Cirad, Inra, IRD, Montpellier SupAgro

Primary production in terrestrial ecosystems is regulated by radiation interception and the acquisition of resources, most of which are found in soils (water and nutrients). In ecosystems affected by human activities, this plant production function has long been maintained through management of inputs (mineral, organic) and soil physical and chemical properties. Through this strategy, global food production doubled between 1960 and 1995, but inputs of nitrogen fertilizer increased by almost sevenfold, along with a more than threefold rise in phosphate fertilizer inputs over the same period. Given the environmental impacts of these practices, this strategy cannot provide a sustainable response to the need to increase crop production to fulfil the food requirements of a growing population in the coming decades.

In this setting of increased primary production, management of inputs (chemical and organic) and global change (climatic and land use), the scientific objectives of the joint research unit Functional Ecology and Biogeochemistry of Soils (UMR Eco&Sols, CIRAD, INRA, IRD, Montpellier SupAgro) are to gain insight into, describe and predict factors that determine primary production in Mediterranean and tropical ecosystems, and especially ecological processes involved in ecosystem services that regulate mineral flows—primarily carbon and nutrients, nitrogen and phosphorus— in these agroecosystems. From an environmental standpoint, research is focused on carbon sequestration and greenhouse gas emissions and, secondly, on the ecodynamics of biological contaminants (viruses, Bt proteins, etc.). This research is in line with the aims of international (Millennium Ecosystem Assessment) and French (Grenelle de l’Environnement) initiatives concerning links between ecosystem services and human well-being.

To achieve these objectives, UMR Eco&Sols conducts studies to determine the impact of plants and soilborne organisms (plant roots, earthworms, termites, nematodes, fungi, bacteria), as well as interactions between them and with their environment in biogeochemical cycles within agroecosystems. This ecosystem-oriented strategy is focused on functional communities and interaction networks and is pivotal to laboratory (microcosms and mesocosms) and field research approaches geared towards the development of ecological engineering to reconcile sustainable agricultural production objectives and the preservation of agroecosystem environmental services. The stability and resilience of these functional communities to climate change and altered land-use patterns are studied in different Mediterranean and tropical soil-climate conditions, in collaboration with national agricultural research centres and universities in developing countries. These experimental approaches are closely associated with a modelling approach devoted to formalizing biological and biogeochemical processes that govern soil-plant interactions and to predicting flows in agroecosystems.

The UMR is based in France (Montpellier) and in several tropical countries in West Africa (Senegal, Burkina Faso), Central Africa (Congo), Madagascar, Southeast Asia (Thailand) and Latin America (Brazil, Costa Rica). The main agroecosystems studied include cereal and legume cropping systems, and tree crop stands for forestry (eucalyptus and maritime pine), agroforestry (coffee) and latex (natural rubber) production.

Annual and perennial legumes are introduced and managed in mixedspecies stands under a range of different soil-climate and agricultural conditions, especially in low input systems.

Director: Laurent Cournac

68  scientists

Unit website

List of research examples/projects for the resarch unit UMR Eco&Sols Functional Ecology & Biochemistry of Soils & Agroecosystems (in French) 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. (...)

Sharing major nutrient resources and uptake facilitation in intercropped cereal-legume systems: a case study on phosphorus

Intercropped peaduram wheat in a phosphate fertilization trial at INRA Toulouse- Auzeville (France).P. Hinsinger © INRA

In light of the importance of ecological intensification in agrosystems, the phosphorus issue is especially worrisome because of the finite nature of natural phosphate resources, which is the main source of phosphate fertilizers. The shortage of these fertilizers will be a major problem within a few decades, so solutions are urgently needed. Among the promising (...)

Nitrous oxide emission dependent on soil cover management in agroecosystems in Madagascar

Monitoring N2O emissions and key associated parameters in a maize-soybean DMC cropping system SCRiD research station, Madagascar).  - © E. Blanchart

In Madagascar, direct seeding mulch-based cropping systems (DMC) have been developed as an alterative to conventional systems based on soil tillage, which are unable to effectively meet the major challenges of land conservation, environmental preservation and food security. DMC systems combine no tillage and organic matter management (crop residue left on the (...)

Nitrogen cycle and the role of shade legumes in coffee cropping systems in Costa Rica

In Central America, agroforestry systems provide an alternative to intensive high-input coffee monoculture systems which have trouble reconciling production, environment-friendliness and cost-effectiveness. Agroforestry systems have a carbon storage potential, while also reducing nitrate leaching and emissions of nitrous oxide, a major greenhouse gas. However, (...)


Update on 19/04/12


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