Adsorption and Mobility of Metribuzin in Soil

Abstract

The sorption equilibria and relative mobility of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] were evaluated on 16 soils from the lower alluvial flood plain of the Mississippi River as a function of soil properties. Metribuzin sorption and mobility were significantly correlated with each other and both parameters were significantly associated with clay content, organic matter, and water content at 0, 0.33 field capacity (FC), and 15 bars tension. Prediction equations for adsorption (K1= −1.10 + 0.08 FC) and mobility (Rf= 0.81 − 0.015 FC) indices were developed based on water content at 0.33 bar tension (FC). A competitive effect was observed between the combination of various levels of clay and organic matter as related to metribuzin adsorption.