DISPONIBILIDADE DE CÁDMIO EM DIFERENTES SOLOS DO RIO GRANDE DO NORTE

Abstract

This work had as objective studying the extraction of cadmium and evaluate four extractors as conventional chemical: Mehlich-1, Mehlich-3, TEA-DTPA and CaCl2 as indicators of the availability of cadmium in plants (Zea mays) in soils of the state of Rio Grande do Norte. The soils were submitted to the correction of pH and chemical and physical analysis. The determination of total cadmium in samples of soil, were made through the technique of digestion digesters in tubes containing nitric acid with the ratio of 3:1 v / v (aqua regia). The extracts were read by the atomic absorption spectrometry, setting up the total concentration of cadmium in the samples. For the extraction of cadmium in the plant samples were submitted to digestion nitric-perclórica will ratio of 3:1 (v / v). Statistical analyses were made in the programme Statistic 6.0, where the data were submitted to the analysis of variance and correlation, is adopting levels of significance of 1% and 5% probability. The capacidae recovery of extractors used followed the following order: Water Régia> Mehlich-1> Mehlich-3> DTPA-TEA> CaCl2. The aqua regia was a good extractor for phytoavailability, presenting the second highest correlation coefficient. The CaCl2 was given the best extractor due to the availability has presented better correlation between the cadmium content in dry plant maize and extracted by extratoras tested solutions. On average the Neossolo Quartzarênico led to better absorption of cadmium by plants of maize and Neossolo Flúvico and Haplic Cambisol the minors.