Army worms are the scourge of duck plantings because the are usually growing good and are nice, green, and succulent when army worms are at their worst.
So - I have a couple areas with thick smartweed, still has some water standing. If summer heat ever shows up and if it quits raining - these areas may start drying out - but not soon enough to plant with conventional tillage. But, I am extremely interested in your method. How long after spraying do you broadcast the seed. You did nothing but spray and then broadcast?