In the Rougiers de Camarès area (Aveyron, south of France), cultivated hillslopes are susceptible to hydric erosion. It results from physical conditions (steep slopes, soft bedrocks, thin soils), climate agressiveness (frost, storms, drought), as well as farming systems (tillage intensification, short crop successions, soil compaction). The main objective of this work was to study the effect of cultural practices (flat or raised moldboard plowing, superficial tillage, direct drilling, with mineral fertilizers or sheep manure) on soil erodibility, aggregate stability and carbon content in a Rougiers Entisol (Udorthent). Another objective was to study the relationships between soil erodibility (which was assessed by field rainfall simulation on manually retilled bare dry soil), water-stable aggregation (which was assessed by immersion and wet-sieving) and soil carbon content in the 0-10 cm depth layer. Runoff and soil losses were high in the plowed plots, lower in the direct drilling plots (where runoff remained rather high, however) and intermediate in the superficially-tilled plots, with no clear effect of the inputs (table 1, figure 1). In the fertilized plots, water-stable macroaggregation (> 0.2 mm) was higher in the direct drilling plots than in the plowed ones; on the other hand, it did not vary significantly among the manured plots (figure 2). Carbon content profiles showed a carbon concentration near the surface in the direct drilling and superficially-tilled plots, but its dilution within plowed layers (figure 3). Runoff, turbidity and soil losses (product of runoff and turbidity) were related to water-stable aggregation and soil carbon content in the 0-10 cm layer. At the beginning of the rain (30 min), runoff and soil losses were closely correlated to water-stable macroaggregation, but not to carbon content (table 1, figure 4) although there was a correlation between water-stable macroaggregation and carbon content At the end of the rain (runoff steady state), turbidity and soil losses were closely correlated to soil carbon content, and to a lesser extent, to water-stable macroaggregation (table 1 figure 4). The effect of cultural practices on erodibility therefore depended on their effects on wafer-stable macroaggregation and carbon content in the superficial soil layer.