Zinc, lead and cadmium influence in rice plants (Oryza Sativa L.) cultivated in soil with addition of siderurgical residue

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">The effects of application of siderurgical residue, originated from the zinc concentration in siderurgical high-ovens mud, as supply of zinc for rice plants (Oryza Sativa L.) and the toxicity due to cadmium and lead from the residue, were studied in a greenhouse experiment.The period of the experiment was from April of 2005 to March of 2006. The soil materials were from the A and B horizons of a Yellow – Red Oxisol, and the A horizon of an Entisol, from Pinheiral municipality, State of Rio de Janeiro, and the rice (Oryza Sativa L.) variety utilized was the “BRS Curinga”. There were applied four dosages of residue (94; 281; 844 and 2531kg ha-1) plus the testimony, without residue. The amount of zinc, cadmium and lead was determined in the root and aerial part of the rice plants. The plants cultivated in the A horizon of the Entisol presented the biggest dry biomass production, the highest zinc accumulation, and the smallest cadmium level. The plants cultivated in the Oxisol B horizon had the smallest dry biomass production, lowest zinc accumulation, and the highest level of lead. As for the Oxisol A horizon, the rice plants showed a good dry biomass production. The zinc and lead concentrated, mainly, in the roots; and cadmium in the aerial part. Based on the characteristics of the studied soils, and the fitotoxicity by lead showed in the rice plants grown on the Oxisol B horizon, the application of the siderurgical residue, is not recommended, as a zinc source for the rice crop.