In the 0.30 m deep pits, in the same layers (i, ii, and iii), disturbed
samples were collected. In the laboratory, these samples were dried in
shade until they reached the humidity corresponding to the friability
point. Next, they were sieved in a 9.52mmmesh sieve, breaking aggregates
larger than 9.52 mm in their weak plans. Later on, a part of the
sample was sieved in a 2 mm mesh sieve to determine particle size,
water dispersed clay (Gee and Or, 2002) and the soil organic carbon
through the Walkley–Black method. The remaining sample was used
to quantify the water stability of aggregates, adapted from the method
described by Kemper and Chepil (1965), using the Yoder (1936) vertical
oscillationmachine. Each sample of air dried soil was homogenized and
then divided into four subsamples uniformly distributed aggregates.
Three of these were used for wet stability measurements and one for
water content assessment. Thus, the wet stability tests had three replicates
per plot depth