Duck and Fruit Trees/Bushes

Hello! This is my first post here, but I was hoping to find some guidance, so I’ll just jump right into it.

I’m putting together an orchard (apple, pear, plum, and sugar maple) with some fruits (raspberry, blueberry, blackberry, elderberry). The orchard area is attached to the duck yard.

Now, I don’t have the ducks yet (or all the plants for that matter – that’ll take years) but I’ve got conflicting information online. I’d like to let the ducks wander the orchard, but I’ve read that the nitrogen in their waste can poison young trees. “Young” is anywhere from 1-5 years, according to a quick Google.

The trees I have in now are 1-2 years old. The combined orchard and duck run are about 2 acres. Would this be enough space to diffuse the waste? Or would I have to block access to the trees until they were grown?

Thanks in advance to anyone who replies 🙂