Zinc in soils of the state of São Paulo 1: total zinc

Determinations of total zinc, extracted with HF-HClO4, were carried out in 227 samples of 28 profiles of 14 soil units of the State of São Paulo, using the atomic absorption spectrophotometry. The amount of zinc found in the different soils was mainly determined by the zinc content of the soil forming material. In soils derived from basic igneous rocks, those richest in zinc, the weighted average contents of their A horizons were between 87 and 315 ppm; in those derived from alluvial and coluvial materials the contents were 53 and 84 ppm; in those derived from modern sediments the contents were batween 29 and 65 ppm; in those derived from Bauru sandstone the contents were between 16 and 30 ppm and in 'those derived from modern sandy sediments, the contents were between 1 and 17 ppm. A significant correlation (r = 0,79**) was determined between the Fe2O3 end the total zinc contents in the studied soils.

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