Transport to ground-water of six commonly used herbicides: a prediction for two Italian scenarios

In Italy suitable standard scenarios for pesticide risk assessment based on computer models are lacking. In this paper we examine the use of the VARLE ACH model to assess the potential danger of ground-water pollution by six h erbicides (alachlor, atrazine, cyanazine, linuron, simazine and terbuthylaz ine) which are used to protect irrigated (maize) and non-irrigated (sorghum ) crops in the Po Main, one of the most important agricultural lands in Ita ly. Two extreme scenarios are taken: red worst case (sandy soil) and real b est case (clay loam soil). The simulation suggests that cyanazine, Linuron and terbuthylazine can be s afely used in clay loam soil in both non-irrigated and irrigated crops, whi le alachlor, atrazine and simazine can be safely used only in non-irrigated crops. On the other hand, the application of all the herbicides tested sho uld be avoided in sandy soil, with the exception of linuron in non-irrigate d crops. (C) 2000 Society of Chemical Industry.