Geoscience Reference
In-Depth Information
Fig. 12.34 Average a CaBr
2
,
b terbuthylazine, and
c bromacil concentrations in
the soil profile following
89.5 cm of leaching (Toiber-
Yasur et al.
1999
)
that, in the case of bromide, there is a continuous displacement of the center of mass
with cumulative infiltration. In contrast, the bulk of the herbicide contaminant mass
remains in the upper soil layer, with very little displacement.
Figure
12.35
shows the spatial distribution of terbuthylazine and bromacil
concentrations in a vertical cross section, after leaching by successive irrigations.
Differences between the concentrations of the two herbicides may be explained in
terms of the chemical properties and the soil spatial variability. The bulk of the
terbuthylazine remained close to the surface, being strongly affected by adsorption.
