Modelling the continuous exchange of carbon between living organisms, the soil and the atmosphere Ibrahim, H. /Pansu, Marc /Blavet, Didier Hatira, A. McDonald, P. /Bernoux, Martial Drevon, J. J. Carbon flows Microbial biomass Microbial exchanges Model proposition Agro-ecology Global change This study evaluated a framework for modelling the continuous exchange of carbon (C) between the atmosphere, plants, humus, and microorganisms, proposing a plant C model coupled to MOMOS, an existing microbial C model. C data were collected on low fertility cereal-legume cropping systems. Plant C and microbial C were modelled simultaneously and the growth parameters of plants and nitrogen-fixing microorganisms were fitted to the data. All C exchanges were successfully predicted using the same weather correction for plant and microbial processes. Most of the photosynthetic production was allocated to the roots, reducing yields. The C losses were found modelled mainly by root respiration for cereals, probably as an energy source for nutrient explorings, and by root mortality for legumes as a growth source for decomposers and symbiotic nodules. The effect of root-nodule activity on shoot growth was found non-linear. The system was modelled as a sink of 4.2 Mg C ha(-1) year(-1) in the soil's labile C reserve. This paper coordinates theoretical bases for modelling the processes regulating plant productivity associated with plant C losses. The tool appears to be robust and is now available for calculating the essential parameters of agro-ecology and climate change. 2016 text https://www.documentation.ird.fr/hor/fdi:010066212 fdi:010066212 Ibrahim H., Pansu Marc, Blavet Didier, Hatira A., McDonald P., Bernoux Martial, Drevon J. J.. Modelling the continuous exchange of carbon between living organisms, the soil and the atmosphere. 2016, 398 (1-2), 381-397 EN