Efeito do silicato de cálcio na fitoextração induzida em solo contaminado por chumbo.

Abstract

The silicon uptake by plants results in amelioration of metals phytotoxicity. Such outcome can enhance phytoextraction owing to increased plant tolerance to metals. The critical levels of Si in plants and soils, as well as the best extractant to be used in soil, are still matter of discussion. The work aimed at evaluating the effectiveness of methods for Si extraction from soil (calcium chloride, acetic acid, citric acid, and water). In addition, the biomass yield, concentration and content of Si in maize plants grown in a Pb-contaminated soil were also studied. Si was applied at the rates 0, 100, 250, 350, and 500 mg kg-1 in 5.5 dm-3 pots in which 65 days old plants were cultivated. The Si doses promoted biomass reduction but increased the Si concentration in roots and shoots. However, applying up to 100 mg kg-1 of Si enhanced biomass. Calcium chloride and acetic acid were the extractants best correlated with Si concentrations in plants.