CARACTERIZAÇÃO NUTRICIONAL DE BRANQUILHO (Sebastiania commersoniana (Baillon) Smith & Downs - Euphorbiaceae), CULTIVADO EM SOLO CONTAMINADO POR PETRÓLEO

One year after a large oil spill near President Vargas Refinery, in the state of Parana-BR the effect of soil contamination on the nutritional status of S. commersoniana (Euphorbiaceae) seedlings was studied. In a field experiment, seedlings were planted on contaminated, not contaminated and biorreclamated soils. In a greenhouse the experiment consisted of four treatments: contaminated soil, not contaminated soil, contaminated soil + fertilizer and not contaminated soil + fertilizer. Seedlings were grown for 15 months at the field experiment and for 11 months in the greenhouse at the end of which plants were cut off and composite samples of leaves and stems were analyzed for macro and micronutrient content. Results for leaves showed statistical differences on average K, Mg and Fe contents. Contamination semmed to result in a decrease in K and an increase in Mg and Fe content. Significant reductions in Ca, Fe and Al contents were also observed in the stems. In the greenhouse experiment fertilizer addition lead to unclear results. A reduction of Mg and increase in Mn and Zn in the leaves on non contaminated soil was observed. In the stems higher N contents were found in the contaminated soil with addition of fertilizer, and also higher levels of Fe in contaminated soil regardless of fertilization. The results could have been strongly influenced by the complexity of soil morphological, chemical and physical characteristics of the alluvial plain.