The study of soi morphology, combined with that of free Fe and Al and organic matter, for the first 10cm of B horizon, shows the existence of 9 statistically different changes in podzolization intensity along the trench. The coefficient of variation (CV) of principal chemical properties varies generally from large (30%) to very large (60%) so that except for pH, a large number of samples is required to estimate their means with a precision of 10% of that mean ( 95%). As far as grain size components of this sandy soil are concerned, the CV is low (11%) for sand, larger for silt (24%) in B (10cm) horizon and always large (35%) for clay, which is not very abundant.-from English summary