Increases or decreases in DHA were obtained in the soils treated
with different doses of mesotrione after different incubation times. Significant
differences were observed in DHA mean values for the unamended
soils (LSD = 15.5, p b 0.05), and the SS- and C-amended
soils (LSD = 4.05, p b 0.001 and LSD = 50.1, p b 0.05, respectively) during
the incubation in all cases (control and soils treated with
mesotrione). At time 0 days, DHA decreased significantly in the unamended
soil and in the SS-amended soil treated with mesotrione at
10 and 50 mg kg−1 dw, respectively, and increased significantly in the
C-amended soil treated with mesotrione at 2 mg kg−1 dw. After 28
and 84 days of soil incubation, DHA values decreased in the unamended
and C-amended soils (control and treated at 2 mg kg−1 dw) or increased
in the unamended and amended soils at 10 mg kg−1 dw, but
no changes were observed in soils with mesotrione at 50 mg kg−1 dw.
Fig. 3 includes the ANOVA results between sampling times for each herbicide
dose (lower case letters), and no significant differences between
treatments were indicated with the same letter.