The Nebraska Department of Agriculture (NDA) has shared a document on its website providing runoff mitigation guidance to users of the herbicides Enlist One and Enlist Duo. Both Enlist herbicide labels require the applicator to select mitigation measures to avoid product runoff from the application site and subsequent surface water contamination. Each mitigation measure is worth a certain number of “credits.”
For example, use of contour buffer strips is worth two (2) credits. Applicators must know the Hydrologic Soil Group (HSG) for the area to be treated. If the application will be made to soil in Hydrologic Soil Groups A or B (sand, loamy sand, sandy loam, or sandy clay loam), the applicator must employ enough mitigation measures to add up to at least four (4) credits.
If the application will be made to soil in Hydrologic Soil Groups C or D (silt loam, loam, clay loam, silty clay loam, sandy clay, silty clay, or clay), the applicator must employ enough mitigation measures to add up to at least six (6) credits.
NDA’s new guidance document helps applicators use an online USDA tool to determine which HSG(s) are present in their field. If multiple HSGs are present in a field, NDA recommends following the more restrictive requirements for the entire field.
If a grower plans to hire a custom applicator to apply an Enlist herbicide, the grower should communicate this soil information to the custom applicator. Lastly, a field’s HSG(s) should not change over time. Therefore, NDA recommends that growers save a permanent record of this information for their fields for use in the future.