The official response to the millet question from the United States Fish & Wildlife Service:

Dear Brian,

Thank you for your inquiry regarding Federal baiting regulations and waterfowl hunting . Our mission is working with others to conserve, protect, and enhance fish, wildlife, and plants and their habitats for the continuing benefit of the American people.

Your question is concerning wildlife food plots and whether or not a person may legally hunt waterfowl over first year planted millet. Nothing in the regulations prohibits you from hunting waterfowl in wildlife food plots, including those planted with millet, unless the seed has been freshly distributed, scattered, or exposed. Therefore, food plots with standing millet may be legally hunted, even in the first year of growth. Because wildlife food plots do not meet the definition of a normal agriculture planting, harvest, post-harvest manipulation, or a normal soil stabilization practice, any millet planted in these areas could not be manipulated for purposes of waterfowl hunting at any time. You also asked for clarification of when millet is considered a natural vegetation. Natural vegetation does not include planted millet because of its use as both an agricultural crop and a species of natural vegetation for moist soil management. However, planted millet that grows on its own in subsequent years is considered natural vegetation.
You can find more information about migratory bird hunting and baiting regulations on our web site at: http://www.fws.gov/le/HuntFish
You can find the waterfowl baiting regulations in 50 CFR Part 20 at: http://www.gpoaccess.gov.

Thank you for your cooperation in complying with our regulations that help protect fish, wildlife, and plants and their habitats. Please feel free to respond to this message with any further inquiries that you may have regarding this matter.

The email address to respond to if anyone has further questions is R9LE_WWW@fws.gov.