Pharmacology, Toxicology and Environmental Health Commons^™

Atrazine Runoff In The Blue River Basin: Geomorphology, Rainfall, And Agronomic Practices, Kundan Dhakal

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Atrazine concentrations in the Big Blue River Basin (BRB) in Nebraska and Kansas periodically exceed the U.S. EPA Maximum Contaminant Level (MCL) of 3 µg L^-1. The present study is focused on watershed variables influencing surface runoff of atrazine. The assessment includes the impact of corn and sorghum planting progress (indicating atrazine application), rainfall, antecedent soil water content, and soil restrictive layer on stream-measured weekly atrazine load in independent BRB subwatersheds for 1997 - 2004. Maximum atrazine loading occurred after most of the corn had been planted but during sorghum planting from mid-May to early June, immediately following …