Leaching of broadcast and banded atrazine from maize plots

There are few reports that compare losses of atrazine 16-chloro-N-ethyl-N'- (1-methyethyl)-1,3,5-triazine from band and broadcast applications. A field study was conducted in Connecticut to determine the leaching losses of atr azine when applied to maize (Zea mays L.) in 15-cm bands over the rows or b roadcast onto the entire plot. Estimates of leaching losses were made with zero-tension pan lysimeters. The experiment was set out as a randomized com plete block design with four replicates and treatments were method of appli cation (broadcast vs. band) and location of lysimeters (row vs. interrow), Water samples were analyzed for atrazine and related s-triazines using enzy me-linked immunosorbent assay (ELISA), There was a greater (P < 0.01) frequ ency of water samples with atrazine detections from the broadcast applicati on (>99%) than from the band application (82%), Atrazine concentrations als o were more likely (P < 0.01) to be above the maximum contaminant level (MC L) of 3 mu g L-1 from broadcast treatments (7.1%) than from band treatments (0.7%), Concentrations and mass loss of atrazine were three to four times greater (P < 0.05) in the broadcast treatment than in the band treatment. T here were significant (P < 0.05) differences in concentrations and mass los ses of atrazine between row and interrow locations of lysimeters for band a pplication but not for broadcast application. Maize yield was not reduced b y band atrazine application with interrow cultivation. There is less potent ial of groundwater contamination from atrazine when applied in a band than when applied broadcast.