CONTAMINATION OF GROUNDWATER BY TRIAZINES, METOLACHLOR AND ALACHLOR

The movement of triazines (atrazine, simazine, cyanazine), metolachlor and alachlor were studied in continuous irrigated corn in an Evesboro loamy sand soil. Both no-tillage and conventional tillage treatments were used. Atrazine and simazine were detected in the groundwater more frequently than cyanazine and metolachlor. Alachlor, atrazine and sim azine moved rapidly to the groundwater if sufficient rainfall occurred shortly after they were applied. Alachlor concentrations ranged from 4.0 to 15.0 ppb and atrazine concentrations ranged from < 1.0 to 54 pp b. Metolachlor was detected in the groundwater more frequently than cy anazine. Metolachlor concentrations range from < 1.0 to 12.0 ppb and c yanazine concentrations ranged from < 1.0 to 29.0 ppb. There was no la rge differences in pesticide movement between conventional tillage and no-tillage.