Study on belmviour of pesticide Dimehypo in soil

Degradation，adsorption and field fate of pesticide Dhnehypo have been investigated．The results are as follows：hydrolysis of Dimehypo is very slow under pH range of 3 to 9．Degradation of Dimehypo in soil is mainly microorganism-related．Furthermore，Dimehypo and Nereistoxin can be rapidly degraded under ultraviolet light．Adsorption of Dimehypo by soil is negligible，while Nereistoxin can be sorbed‘o a large extent．After foliar spray in the rice field。distribution of Dimehypo concentration has the following sequence：crop>field water>soil．Field trials have proved considerable tendency of pesticide to leach down the profile，particular attention should be paid to threats of Dimehypo posed to the groundwater．