Abstract: Through fields-scale experiment and leaching-pond experiment,characteristics of the loss of water-resolvable pesticides from rice fields and their affecting factors were studied.In the experiment,the losses of monosaltap and dimethoate were estimated.The results show that the loss of monosultap by way of drainage and leakage was 208.0 and 222.0 (g·hm^-2),respectively,forming a total loss percentage of about 14.3%;while the loss of dimethoate via drainage and leakage was 238.5 and 160.8 g·hm^-2,respectively,forming a total loss percentage of about 13.4% from the rice fields.

Key words: water-resolvable pesticide, monosaltap, dimethoate, rice field, drainage, leakage, loss, degradation