This study was developed with a soil contaminated by heavy metals, with the purpose of evaluating the action of silicon and phosphorus as protection agents through simple extractions by DTPA. The collected samples were prepared and incubated with five doses of silicon and five doses of phosphorus, with four replicates, amounting to 100 experimental units. After 30 and 60 days, samples of each treatment were collected, submitted to pH analyses and simple extraction by DTPA. The amounts of DTPA-extracted metals depended on the doses of silicon and phosphorus and on the pH. Treatments with silicon and phosphorus was efficient in decreasing the availability of heavy metals in soil.

Este trabalho foi desenvolvido em um solo contaminado por metais pesados de uma área de extração e industrialização de zinco pertencente à Companhia Mineira de Metais, em Três Marias, MG, com o objetivo de avaliar a eficiência do silício e do fósforo como agentes amenizadores da toxidez dos metais pesados. As amostras coletadas foram preparadas e incubadas em frascos de polietileno, com umidade equivalente a 60% do volume total de poros. Foram utilizados 25 tratamentos: cinco doses de silício (0; 2.340; 6.040; 9.860 e 13.660 mg dm-3) e cinco de fósforo (0; 90; 180; 360 e 720 mg dm-3), com quatro repetições, totalizando 100 unidades experimentais. Aos 30 e 60 dias, coletaram-se amostras de cada tratamento, submetidas a análises de pH em água e extrações simples por Mehlich-1. Os teores extraídos receberam influência do silício, do fósforo e do pH. Os teores de Zn e Cd, embora reduzidos, permaneceram acima dos níveis permitidos. O Pb diminuiu influenciado pelo incremento de silício e fósforo a níveis inferiores aos permitidos.

This work was developed on a soil contaminated by heavy metals from a zinc-extracting and industrializing area belonging to the Companhia Mineira de Metais at Tres Marias, Minas Gerais state, Brazil, with a view to evaluating the efficiency of silicon and phosphorus as ameliorating agents of heavy metal toxicity. The samples collected were prepared and incubated into polyethylene flasks, moisture equivalent to 60% of the total volume of pores. 25 treatments were utilized: five doses of silicon (0; 2.340; 6.040; 9.860 and 13.660 mg dm-3) and five of phosphorus (0; 90; 180; 360 and 720 mg dm-3) with four replicates amounting to 100 experimental units. At 30 and 60 days, samples from each treatment were collected, submitted to water pH analysis and simple extraction by Mehlich-1. The extracted contents received greater influence from both silicon and phosphorous and at a lesser extent from pH. Zn and Cd contents, although reduced, remained above the allowed levels. Pb decreased, influenced by the increase of silicon and phosphorus to level inferior to those permitted.