ETUDE SYSTEMATIQUE DE LA VARIABILITE D’UN SOL PODZOLIQUE, LE LONG D’UNE TRANCHEE DANS UNE ERABLIERE A BOULEAU JAUNE

Abstract

In a 16.5-m long trench dug in a podzolic soil under a sugar maple-yellow birch stand, principal morphological variations have been studied and soil samples have been taken systematically. The study of soil morphology, combined with that of free Fe and Al and organic matter, for the first 10 cm of B horizon, shows the existence of nine statistically different changes in podzolization intensity along that 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 (α = 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(10 cm) horizon and always large (> 35%) for clay, which is not very abundant. Since these soil variations do not follow a regular cycle, the choice of pedon to describe this soil is especially difficult.