Submitted to: American Chemical Society Symposium Series
Publication Type: Abstract Only
Publication Acceptance Date: March 22, 1999
Publication Date: N/A
Previous comparisons of field measured atrazine distributions in the top 50 cm soil provile with PRZM simulations, indicates: PRZM tends to over predict atrazine concentration in the top 10 cm and under predict concentrations in the lower soil depths (10 to 50 cm). These results suggest PRZM does not well simulate the mechanisms of atrazine distribution and transport through the upper soil profiles. We are conducting a series of experiments to assess the effect of selected transport mechanisms on measured and simulated atrazine distributions in Topics include: atrazine retardation during infiltration, distribution of atrazine between application and the first rain event, estimation of the fraction of surface area involved in transport,and an evaluation of MACRO's (a model with macropore component) ability to simulate atrazine transport through the crop root zone to a depth of 1.8 m, and PRZMs ability to simulate atrazine distribution in the 0 to 10 cm horizon for the first tow weeks after application.