The geese seem to do the most damage, however the deer are right up with them, fence and some odorous material like old highly perfumed soap, moth balls solve that problem around the garden.
Geese are unreal here, they are not native, yet 30 of em reside in our 20 acre pond, they brood their young and turn into destructive grazing monsters immediately. They nip all the corn, can really clean off the tops of oats in short order, but with some harassment, not much damage is really done, unless you do nothing to keep after em. Cat & mouse, you shoot, they leave, they come back, hide behind a knoll, you find em again, shoot, they leave, harass, take and capture their young, hold em up and make em really mad, thinking that will keep em out, nope, best thing is to wipe a bunch out, take the breast meat if so inclined or leave em, coyote, fox and what have you will come in and be around, they get some at night, but they still show up.
I have never found a way to rid them, never been able to oil the eggs when it needs to be done, not sure about scarecrow and enemy decoys, they get used to everything, I've shot one and left it in plain sight, that does not work either.
What gets me is they will reside in a fallow field, with little grazing, maybe cause its open, not high grasses, weeds, same part of that field where I plant forage for deer, it was mold board plowed and not even disc'd, they are right in that area, once they wiped out a clover patch, years back, that started the war, NYSDEC depradation permits etc. The sight of them in any planted field makes you sick, they have the complete run of 30 acres of corn adjacent to the pond this year and have nipped the tops, but I don't think it will amount to much as the corn seems to be ok with it at the 4 leaf stage which is where its at, they are getting ready to spray soon.
PS, I have a .22 WMR dedicated to their cause, little more wallop than the .17, but that .17 like my friend has in a savage with real tight groups makes a head shot real easy, darned things are just relentless around here, was great when we did not have them, and rarely saw them in the sky, in the fall thousands of them pass through.