TY - JOUR T1 - Reducing herbicide losses from tile-outlet terraces JF - Journal of Soil and Water Conservation SP - 25 LP - 31 VL - 53 IS - 1 AU - T. G. Franti AU - C. J. Peter AU - D.P. Tierney AU - R. S. Fawcett AU - S. A. Myers Y1 - 1998/01/01 UR - http://www.jswconline.org/content/53/1/25.abstract N2 - This study evaluated the effectiveness of various tillage/herbicide management practices for reducing atrazine and cyanazine runoff from tile-outlet terrace systems. Of particular interest was the effectiveness of the 66ft (20-meter), no-spray setback area around tile-outlet riser pipes needed to meet label requirements compared to (1) tilled, 100% sprayed area; (2) no-till, 100% sprayed area; and (3) tilled, 100% sprayed area with herbicide incorporation. Four practices were replicated three times on 12 individual tile-outlet terraces in Iowa, Missouri, and Nebraska. Atrazine and cyanazine were applied at rates ranging from 0.88 to 2.5 lb./acre (0.99 to 2.8 kg/ha). Three runoff events were sampled in Iowa and Missouri, and one in Nebraska. Concentrations of atrazine and cyanazine were greatest from the tilled and no-till plots where 100% of the contributing area was sprayed. Conclusions include (1) incorporation into no-till or disk-till reduced herbicide runoff concentrations by approximately 25% compared to surface application alone; (2) the setback reduced herbicide losses in proportion to the area not sprayed; (3) no-till reduced total herbicide mass loss 94% and 91% for cyanazine and atrazine, respectively, because of a 72% reduction in total runoff volume; and, (4) a comparison of tilled and no-till based on one runoff event suggests greater herbicide mass loss from no-till; however, based on three events no-till shows a reduction in mass loss. ER -