Technical Abstract: SULFENTRAZONE PERSISTENCE IN SOIL REQUIRES MANY CROP ROTATIONAL RESTRICTIONS. THE SORPTION AND MOBILITY OF SULFENTRAZONE PLAY AN IMPORTANT ROLE IN ITS SOIL PERSISTENCE. THUS, A SERIES OF LABORATORY EXPERIMENTS WERE CONDUCTED TO MIMIC THE SOIL PROPERTIES OF CATION AND ANION EXCHANGE WITH DIFFERENT INTERMEDIATES. THE MOLECULAR CHARACTERIZATION AND IONIZATION SHIFT OF SULFENTRAZONE FROM A NEUTRAL MOLECULE TO AN ANION WERE DETERMINED USING A THREE-DIMENSIONAL GRAPHING TECHNIQUE AND TITRATION CURVE, RESPECTIVELY. SORPTION AND MOBILITY OF 2.6X10-5 M 14C-SULFENTRAZONE WERE EVALUATED USING A SOIL SOLUTION TECHNIQUE WITH ION EXCHANGE RESINS AND POLYACRYLAMIDE GEL ELECTROPHORESIS, RESPECTIVELY. SOLUTION PH RANGED FROM 4.0 TO 7.4. AS PH INCREASED, SULFENTRAZONE SORPTION TO AN ANION RESIN INCREASED AND ITS SORPTION TO A CATION RESIN DECREASED. PERCENT SULFENTRAZONE IN SOLUTION WAS PH-DEPENDENT AND RANGED BETWEEN 0 TO 18% AND 54 TO 88% FOR THE ANION AND CATION RESINS, RESPECTIVELY. MOBILITY OF SULFENTRAZONE ON A 20% POLYACRYALMIDE GEL RESULTED IN RF VALUES OF +0.02 AND +0.39 FOR PH OF 4.0 AND 7.4, RESPECTIVELY.