Phytoremediation of Contaminated Soil with Sulfentrazone by Different Density of Crotalaria juncea

Abstract

ABSTRACT: In phytoremediation programs of contaminated soil with herbicides, it is necessary to determine the appropriate density of phytoremediation species, since this practice will contribute to the efficiency of the process. The aim of this study, therefore, was to evaluate the influence of density in Crotalaria juncea on the phytoremediation of contaminated soils with the sulfentrazone herbicide. The experiment was conducted in a greenhouse using plastics pots. The treatments were the combination of density of C. juncea, (0, 60, 120 and 240 plants m-2) and doses of sulfentrazone (0, 200 and 400 g i.a. ha-1). The herbicide was applied on the pots and then the species used for phytoremediation were sown. At 75 days after emergence, the plants were cut close to the ground and discarded. Posteriorly, the bioindicator species for sulfentrazone, Pennisetum glaucum, was planted in each pot. In the absence of previous cultivation of C. juncea, the fresh mass and dry mass of shoot and root of P. glaucum were lower than those obtained with the previous cultivation. As the density of C. juncea increased, there was an increase in fresh mass and dry mass, regardless of the sulfentrazone dose applied to the soil. The earlier cultivation of C. juncea led to the remediation of the soil contaminated with sulfentrazone. The minimum density of C. juncea which allows P. glaucum to develop is 120 plants m-2.