MOVEMENT OF 2,4,5-T THROUGH LARGE SOIL COLUMNS

Abstract

The movement of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) through large soil columns was measured and simulated by means of a model that incorporates adsorptiondesorption and biological degradation processes. Water(3H) and 2,4,5-T (14C) distributions with depth were calculated after each of several irrigations and compared with concentrations of the isotopes measured in soil solution samples collected at several depths via suction cups inserted into the soil columns. The model successfully predicted tritiated water distributions after several irrigations and adequately predicted herbicide concentrations after the first irrigation. Nevertheless, predicted herbicide concentrations in the soil solution after the second and subsequent irrigations were much greater than observed values. The movement of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) through large soil columns was measured and simulated by means of a model that incorporates adsorptiondesorption and biological degradation processes. Water(3H) and 2,4,5-T (14C) distributions with depth were calculated after each of several irrigations and compared with concentrations of the isotopes measured in soil solution samples collected at several depths via suction cups inserted into the soil columns. The model successfully predicted tritiated water distributions after several irrigations and adequately predicted herbicide concentrations after the first irrigation. Nevertheless, predicted herbicide concentrations in the soil solution after the second and subsequent irrigations were much greater than observed values. © Williams & Wilkins 1980. All Rights Reserved.