Abstract

The aim of this research was to investigate the effect of applying sewage sludge combined with wheat crop residue as an organic amendment on the dissipation rate of simazine spiked at 2 and 20 mg kg(-1) in an Andisol soil from southern Chile. Changes in some soil enzymes related to soil quality were measured by spectrophotometry, simazine dissipation rates were measured by gas chromatography, and biomass production in the contaminated soil was evaluated. Results of this study indicated that application of the organic amendment inoculated with Trametes versicolor enabled a decrease in negative effects of the herbicide on soil enzymatic activities and a reduction in final concentrations of simazine (similar to 80% at both doses). The simazine half-life time was reduced from 14 to 10 days and from 36 to 15 days for doses of 2 and 20 mg kg(-1), respectively. These findings prove that the combined strategy of biostimulation and bioaugmentation using these residues can be effectively used to reduce residue pesticides in soils, mainly by increasing the microbiological activity, thus improving simazine dissipation in an Andisol soil.