Transporte de Atrazina en un Andosol y un Vertisol de México

the problem of pesticide migration in agricultural lands is traditionally studied by means of periodical soil, water and plant sampling. more advanced methods are available today, which permit to reduce the costs of field analysis and to predict environmental contamination risk. these methods are based on mathematical simulation of pesticide movement. the process of atrazine migration in a volcanic soil andosol and a vertisol of mexico was studied by means of laboratory experiments in packed columns. different atrazine doses and steady state unsaturated water flow were applied in the experiments. the 18o and br- water tracers were used to compare atrazine and water movement. the atrazine and water mass balance components were measured, as well as the dynamics of elution. the chemical substances movement theory was applied to interpret the experimental results and to obtain the principal properties of atrazine transport in both soils. the results show that atrazine moves in the andosol 10-16 times slower than water, and 2.5 times slower in the vertisol. five properties of atrazine transport were determined, which can be used to predict the migration of this pesticide so as to minimize the sampling effort in the field, and to assess the risk of soil and aquifer contamination by calculation methods reported in the literature.