Every since I can remember seed corn has been treated with a fungicide and insecticide. In addition today, much of the soybean seed is treated. These treatments help farmers protect yields from insects and fungal diseases resulting in higher yields. Farmers must remember that whatever that seed came in it is pesticide container. That means it must be properly disposed of or sent back to the seed company.
I am a small farmer so I still get all of my seed in 50 pound bags. Most farmers today get their seed in large reusable containers. You must remember that a 50 pound paper bag or container is a "pesticide container." The larger containers are sent back to the seed company to be used again. The 50 paper bags many times used to get burned in the field. In Minnesota it is against the law to burn those paper seed bags. Instead they should be taken to the land fill.
Proper seed stewardship should also be followed if you spill some seed in the field. Seed is very expensive and you try and be careful. But I am sure every farmer has spilled some seed in the field while refilling the planter. You clean up what you can without getting any dirt mixed in with the seed. Then you just leave the rest lying on the ground.
That is not proper seed stewardship. Different species of birds and other animals will eat the seed lying on top of the ground. If they eat enough it can be lethal to birds and other animals. So, if you spill treated seed this spring clean it up dispose of it properly.