Just posting this in case it helps another frustrated gardener sick of having crows pull up new corn and ruining your corn crop. I remember when once, I took my family out for a movie in the middle of the day, and that was just long enough for the crows to decimate my crop, which was fairly large. I was so mad I almost sat out there with a gun. You know the situation, the corn is just coming up out of the ground, and the birds come along and pull out the plants to get at the seed, killing the plant. I suffered this for a few years, doing the usual crap like pie pans, rags, decoys, and the really bad advice of having enough bird food in your bird feeders so the crows would eat the bird food instead of the corn. I think all that did was just attract more crows. Anyway the solution is very simple, and cheap. I wish I could say that I thought very hard about this, but the truth is it was just an accident. Anyway, the fix: when you plant your corn, leave the string up between your row marker sticks. I use string between my sticks, otherwise when I hoe my row, it tends to not be very straight. i.e. stick your two row marker sticks in the soil, tie up your marker string, and hoe your row. Plant the corn, cover it up, but leave the string. When you are done, every single row of corn will have a string over the top of it, and this works 100% at keeping birds from eating your corn. I think they are too afraid of landing in it. Once the corn gets big enough you can get rid of that string. I stumbled across this one year, by leaving a couple of strings up for some reason or another, got attacked by crows, and the 2 rows that had string up were untouched.
Hope this helps,