The evolution of chemical weed control methods has been fundamental to cultivation of large areas where production costs are compatible with national and international markets. Currently, herbicides account for approximately 45.0% of all pesticides used in Brazil. Most of these compounds present long persistence in the environment, contaminating soil, hindering new crops as well as surface water and groundwater, thus leading to environmental problems. The objective of this work was to quantify, using the chromatographic technique, the efficacy of the species E. coracana in reducing picloram persistence in two soils, a Red Yellow Ultisol and a Red Yellow Latosol, treated with this herbicide, and widely cultivated for pastures and crops in Brazil. It was concluded that the species E. coracana is effective in the remediation of soils contaminated by this herbicide, indicating its potential use in programs of phytoremediation of contaminated areas to reduce the risk of environmental impact. Picloram half-life values of the soils evaluated differed for the same weather conditions, probably differing even more under field conditions.
half-life; herbicide; soil decontamination; liquid chromatography
