Will ducks denude a soil?

My wife and I were just talking adding ducks to the farm. Specifically I want to ask others here who have or have had ducks, their experience with a ducks impact on soil and grasses.

If we do this, I'll dig a tiny little pond, likely about the size of a pickup truck, and put up electric net style fence around the pond, a small cluster of trees and some grassy area for them. I plan to keep the grassy area mowed. I know that any pond I dig will be subject to some amount of eutrophication and will grow things as the years pass. I'm open to suggestions and ideas, especially the "I learned this the hard way" suggestions.

Things ducks don't do (that chickens do): Scratch, dig, invert and otherwise scatter the soil. They also don't do dust baths, which can leave pretty sizable craters in the garden or lawn if there is an appealing spot.

Things ducks do: Trample smaller plants, fossick around in the mulch, and eat the more enticing greenery. This tends to be the things we have planted and varies with the breed and also a mix of curiosity and boredom. Most of them don't really eat grass, though, with the exception of Muscovies.

If you keep ducks penned in a small space for any length of time it will end up pretty barren, if not devoid of most plants.  Grasses will persist beyond most other families, and if the area is big enough you can reach an equilibrium. If you're mowing the grass, it will be supercharged with N from the extra fertiliser, so you can put that to good use in other places.

To add to what Phil wrote:

1. The most destructive thing that our ducks do to soil happens if there is a small puddle.  Since they are filter feeders, they'll take advantage of the puddle and burrow into the mud and make some few-inch holes while they suck the bugs out.  This can be preventable if you don't create temporary puddles where the soil is loose and can get muddy.  You can distract the ducks with something else until the water drains; that's what we do when emptying a kiddie pool in an area where we don't necessarily want them digging with their beaks.

2. Our ducks enjoy having access to grass and will nibble along with a meal.  But they don't eat enough grass to make any impact on the health of the grass.  They prefer to eat bugs, produce, and the grains from chicken feed (except for the corn).

3.  Also I should mention, although you might have considered this already, that ducks like to have shade.