Extractors for zinc and copper quantification in soils cultivated with soybean - DOI: 10.4025/actasciagron.v26i3.1832

Abstract

The growint demand of micronutrients analysis, was avaliated the efficiency of acid extractor was evaluated (Mehlich 1), complexante (DTPA) and of the acid combination and complexante (Mehlich 3), for the determination of Zn and Cu of different representative soils of Paraná. The extractors Mehlich 1 was used in the relationship 1:5 and 1:10; Mehlich 3 in the relationship 1:10 and DTPA in the relationship 1:2. The analytic methodologies included the immediate filtrate or the filtrate after decantate of 16 hours; it was still evaluated the filtrate need, comparatively to solution pipetate. The results were appraised through the correlation among the concentration of the nutrients in the soil and in the soy plant. In the evaluation of all the soils, larger efficiency was observed in the extraction of Zn by Mehlich 3; even so in agreement with the texture, Zn was extracted better by all extractors. The extraction of the Cu went more efficient for all the soils when used Mehlich 1 and Mehlich 3. In soil with smaller clay than 470 g kg^-1 the Cu was extracted better by all extractors. The extraction methodologies were equal him, independent of the proportion soil/extractor, of the time of filtrate and of the use of the filtrate or pipetated. The largest texts were found when used the methodology with decantação of 16 hours for Mehlich 1 and Mehlich 3