Observed and Simulated Distribution of Selected Herbicides in Silty Loam, SandyLoam, and Clay Soil Profiles Near Topeka, Kansas, 1986-88

摘要

The report describes the distribution of selected herbicides in the unsaturatedzone and the use of data collected from 1986-88 to evaluate simulations of leaching by PRZM and LEACH. The scope of the report includes determination of the traveltime of five herbicides (atrazine, alachlor, metolachlor, trifluralin, and 2,4-D) through the unsaturated zones of three soil types (silty loam, sandy loam, and clay) under varying rainfall amounts and irrigation practices. The main objectives of the study were to: (1) document observed movement of herbicides through the unsaturated zone of three soil types and (2) compare the observed movement to simulated movement using the Pesticide Root Zone Model (PRZM) and the 'Leaching Evaluation of Agricultural Chemicals Handbook' (LEACH).