Adsorption and desorption of bensulfuron-methyl on Italian paddy field soils

A study on bensulfuron-methyl adsorption and desortion processes has been carried out in three different Italian paddy field soils (silt-loam, sandy-loam and loamy-sandy). The kinetic study has shown that equilibrium was reached in the early stages (twenty minutes) of contact between soil and herbicide. The results of the experiments on adsorption fit Freundlichʹs equation. Koc values have shown that bensulfuron-methyl adsorption mainly regards the clay mineral fraction. The desorption of the pesticide from sandy-loam and loamy-sand soil has resulted to be about 50% when soil washing is carried out with a water volume 7.5 times greater than soil mass, while the amount released from silt-loam soil is 21%.