INFLUENCE OF SOIL PROPERTIES ON SORPTION-DESORPTION OF IMIDACLOPRID

Sorption-desorption studies of imidacloprid o-3-pyridinyl)methyl]-N-ni tro-2-imidazolidinimine) were conducted using the batch equilibration method with seven U.S. soils varying in their physicochemical properti es. Initial imidacloprid concentrations ranged from 3 to 300 mu g L-1. Sorption coefficients K-f and the soil properties organic carbon and CEC gave the higher single correlation coefficients; the latter due to the positive correlation between OC and CEC. Sorption was irreversibl e and desorption hysteresis in general was greater at low soil solutio n concentrations. K-f values were lower at 1:5 soil:solution ratio tha n at 1:1, suggesting a possible effect of a soluble soil component, su ch as salt concentration, on sorption; no significant differences in p H between solutions were detected.