AVALIAçãO DE AGROTóXICOS EM SOLO DE SISTEMAS DE PRODUçãO AGRíCOLA CONVENCIONAL E AGROECOLóGICO

EVALUATION OF AGROCHEMICALS IN SOIL OF CONVENTIONAL AND AGROECOLOGICAL AGRICULTURAL PRODUCTION SYSTEMS. At the Contestado Settlement, Lapa, PR, soil samples from agroecological and conventional environments were evaluated against the agrochemicals alachlor, atrazine, chlorpyrifos and trifluralin. For sampling, 3 depths were considered, 10points were selected, 5 in an agroecological and 5 in the conventional environment, with sampling frequency was at 2-month intervals. The samples were characterized according to textural, chemical and fertility parameters and the data were used in the chemometric study (PCA) demonstrating that the environments are different. The method of extraction, identification and quantification was validated at the trace level. The analytes were analyzed by GC-MS/MS, the recovery values were between 83 to 113%, RSD less than 14%, LD equal to 0.01; 0.0028; 0.004 and 002 μg kg^-1, LQ equal to 0.04; 0.008; 0.011 and 0.05 μg kg^-1, for alachlor, atrazine, chlorpyrifos and trifluralin, respectively. Chlorpyrifos was identified in the Conv3 and trifluralin in the Agro2 and 3 and Conv2 environments. Therefore, the application of pesticides in conventional environments can contaminate agroecological environments. The effect of rain/precipitation on the samples was evaluated by simulation and it was found that the physical-chemical properties of the compounds and the soil have an influence on their behavior in the soil profile.

Keywords:
soil; agrochemicals; GC-MS/MS; agroecological system; conventional system