ADSORPTION OF PARAQUAT HERBICIDE BY DYSTRANDEPT, PALEUDULT, AND PSAMMENT ON VARIOUS CONCENTRATIONS OF NaCl AND MgCl2

The presence of adsorbed Na and Mg in soil, influences the adsorption of herbicide by soil colloid. The objectives of this research were to explain the effect of NaCl and MgCl concentration on paraquat adsorption by Dystrandept, Paleudult and Psamment, to compare the effect of NaCl and MgCl2 concentration on pH and DHL change during the adsorption, and to descriptively compare the adsorption of paraquat by Dystrandept, Paleudult and Psamment. The research consisted of three separate experiments namely paraquat adsorption by Dystrandept, Paleudult and Psamment. The experiment was conducted using CRD with treatments of NaCl and MgCl concentration of 0, 10, 20, 30, 40, and 50 mmol L-1 , respectively and replicated 3 times. Adsorption experiment was conducted using Batch method. The experiment showed that paraquat herbicide adsorption increased as concentration of NaCl and MgCl2 increased. MgCl gave more significant effect on the paraquat adsorption as compared to that of NaCl. Adsorption of paraquat at concentration of 50 mmol MgCl2 L was 3.20 and 3.01 cmol kg-1 for Psamment and Dystrandept respectively, while the adsorption of paraquat by Paleudult was 3.22 cmol kg .The experiment also revealed that adsorption of paraquat by soil colloids caused decrease in pH suspension. Increase in neutral salt concentration caused reduction of pH and increase in EC of the suspension