Herbicide and tracer movement to field drainage tiles under simulated rainfall conditions

摘要: The extent of herbicide and tracer leaching to field drainage tiles may help predict chemical movement deeper groundwater systems. Field experiments were conducted in 1988 1989 measure tile lines during immediately after a simulated heavy rainstorm. eight monitored 1.2 m deep 3.4 long. In 1988, alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide), cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile) Rhodamine WT dye applied 4.5-m2 plots directly over tiles. 1989, alachlor, cyanazine, WT, pendimethalin (N-(1-ethylpropyl)-3,4 dimethyl-2,6 dinitrobenzenamine) used. Chloride or bromide tracers also soil applied. irrigated 24 h application with rainfall simulator. 53 mm was applied, whereas 81 rain 1989. Tile effluent intensively sampled for 8 irrigation. concentration peaks ranged from 1 38 μg l−1. concentrations higher than exceeding 500 l−1 one line. contrast, found only sample, barely above the detection limit. be useful as study profile. all samples containing detected. both years, peaked within 130 min start rainfall. rapid solute depth suggests that preferential flow is an important mechanism affecting transport through structured soils.