Evaluation of weed control practices for profitability and reduction of atrazine concentrations in surface runoff

Excerpt

Atrazine is the most widely used herbicide in corn and soybean production in the Midwestern United States, which produces approximately 80% of the nation's corn and soybeans. More than 90% of raw drinking water samples in northern Missouri have been found to contain atrazine in concentrations that exceed the US Environmental Protection Agency-established maximum concentration of three parts per billion for drinking water. Atrazine is slightly-to-moderately toxic to humans and animals, especially aquatic life. This study was undertaken to identify cost-effective atrazine management practices that reduce atrazine concentrations in surface runoff from the Route J watershed in northeastern Missouri.

The study used an integrated bio-economic weed management model to determine the following for the Route J watershed: (1) atrazine concentrations in surface runoff for different weed management practices; (2) the relationship between corn yield and atrazine or non-atrazine herbicide use based on crop-weed competition and weed management; (3) farm profitability with alternative weed management practices; and (4) policy implications. A geographical information system-based biophysical simulation model (i.e., the Soil and Water Assessment Tool) was used to simulate how different weed management practices influence surface runoff from the watershed. The profitability of alternative weed management practices with and without atrazine were …