Herbicide retention by mulching in corn, under no-tillage system

Abstract

The objective ofthis trial was to study the reactions ofthe residual herbicide mixtures metolachlor plus atrazine and atrazine plus isoxaflutole applied in pre-ernergence for com under no-till system. The experiment was settled in Londrina, using black oat (Avena strigosa) mulch. A randomized complete block design was used. The treatments comprised the following rates ofherbicides: zero, 0.5N, 1.ON, I.5N and 2.0N (N=normal rate ofherbicide). In the present study, N=21 00 g/ha metolachlor + 1400 g/ha atrazine and 1660 g/ha atrazine + 68 g/ha isoxaflutole. Twenty four hours after herbicide applications, 48,3 mm ofwater was applied in the experiments . In the next day, samples of soil and straw were taken for chromatographic analysis purposes. The results showed that 50% of the metolachlor and atrazine leached from the straw to the soil. Approximately 10% of atrazine and 30% of isoxaflutole were detected in the soil after irrigation.