In theory you can buy organic sunflower but 2004 was a very bad growing year so you might have a bit of a hunt and the price might not really be reasonable for feeding wild birds. After poking around a little in an attempt to get some updated information, I'm inclined to think you can go on feeding your sunflower as the U.S.D.A. has been reined in, at least somewhat, on this issue.
Here's a link to a symposium on the problem. The National Audubon Society position is near the end, so you have to read down:
http://www.aphis.usda.gov/ws/nwrc/symposia/blackbirds/abstracts.htmlYou'll see as you read down that it's a difficult issue since sunflower seeds are difficult to protect. Organic farms net each head which adds substantially to the cost because of the hand labor involved.
Most sunflower is not raised to feed birds. It is raised for oil. After several years of falling production, in part because of failure to find a way to deal with Redwinged Blackbirds without creating public outcry, sunflower production is again rising because of higher demand. (Sunflower oil can replace trans-fats which are being removed from the market for health reasons.) Even if no one ever bought any bird seed ever again, there would still be a growing commercial sunflower market.
A few years back, the U.S.D.A. proposed a huge program to poison Redwings and other crop pests. They are not a branch of Fish and Wildlife after all, their first concern to promote agriculture. Indeed, Fish and Wildlife objected to this proposal. Because of the public outcry, this huge program of mass poisoning was cancelled. Now the U.S.D.A. is still a little free at times with depredation permits, but they know they are being watched.
I don't think it's realistic to expect that no blackbirds will be killed where any grain is raised. Many (maybe most?) fields in Minnesota that are being converted to sunflower were formerly growing soy, which is no friend to the birds either. I guess my final answer is that U.S.D.A. knows that eyes are on them when they get too permit-happy.
The big problem is that every agency wishes to become more powerful and U.S.D.A./APHIS continue to propose large blackbird kills -- for instance in 2004, they proposed to kill 2 million blackbirds. Their proposal was again shot down after testimony from the Fish and Wildlife Service, as well as the American Bird Conservancy and other groups.
We just have to keep an eye on U.S.D.A. They are trying to protect our food sources, but they go a bit overboard when not watched.
The conservation movement is a breeding ground of communists
and other subversives. We intend to clean them out,
even if it means rounding up every birdwatcher in the country.
--John Mitchell, US Attorney General 1969-72