Agricultural soil could be a major sink of carbon with appropriate cropping system and soil management. This study aimed to evaluate the potential of CA cropping systems to store carbon into soil from belowground biomass. Three cropping systems were compared: (1) rotation of upland rice followed by maize intercropped with Crotalaria grahamiana, with no tillage (R-MC_NT), (2) rotation of rice followed by oat (Avena sativa) intercropped with vetch (Vicia villosa), with no tillage (R-OV_NT), and (3) rotation of rice followed by maize intercropped with common bean, with conventional tillage (R-MB_CT). The two components of the rotation were cultivated each year. Maize, rice, crotalaria, common bean, oat and vetch were fertilized with 5 Mg ha-1 of “improved” manure. The experiment was conducted in a research station. Hénin & Dupuis model was used to simulate the change of soil carbon content according these three treatments. Compared to the total carbon input by both above- and below- ground biomass, 29%, 34% and 46%, so 1.40, 1.70 and 1.14 Mg ha-1, were attributed by plant roots, for R-MC_NT, R-MB_CT and R-OV_NT systems, respectively. Simulations in 20 years showed higher increasing of carbon stored with R-MC_NT system (from 71 to 84%). (Texte intégral)