Effect of the Silicon in the Extraction of Cadmium by Native Plants of Brasilian's Savanas.

That trial of decontamination of soil for plant, to fitoextração, search capable species of extract metals of him soil on a large scale, without injure his development. The native plants of brazilian’s savannas (Cerrado) can be promising, seen that these are adapted to diverse conditions of stress, and one of the factors that possibly helps in that adaptation is the accumulation of silicon. The effect of the silicon in diminish the stress caused by some metals already was shown, as by example, the cadmium. This interaction can occur due to the immobilization of the metal in soil, or by interactions that occur inside the plant. Like this, the native plants of him closed can be capable of accumulate big quantity of cadmium, beyond that, the application of silicate can function like heavy metals immobilization factor in him soil. Aiming at verify these hypotheses; this work utilized two native species of Cerrado, Psidium firmum (Araçá) and Tabeluia golden (Ipê yellow). In these solos was added chloride of cadmium for obtaining the doses of: 10.0 and 50.0 mg kg-1, maintaining witness without cadmium. In these doses of cadmium was applied 100 mg kg-1 of silicon, with witness without silicon, having like spring the silicate of calcium. The results obtained of this experience showed that the growth of Ipê yellow and Araçá was built up by the presence of silicon, when cultivated in sand’s soil. Being that the Ipê accumulates more silicon, however the Araçá has bigger capacity of resist to the excess of cadmium in the environment of cultivation. The application of silicate shows different effects in the two kinds of soil and for the two species studied.