I have a commercial vineyard, and about mid summer, the grass is brown, and grape plants start looking pretty tasty to the local deer.
I have tried just about everything listed in this discussion, but the only thing that was ever successful was an 8 foot tall woven wire fence. Early on, I tried plastic fencing, but the deer went through it or under it. I also incorporated a deer pass through to allow formovement through the area, which helped prevent testing of the fence line.
25 acres would be cost prohibitive, unless soy beans pay more than I think. I used the double fence method in my mother in laws large garden, and it worked well, deer apparently won't jump a fence if they don't have a clear landing spot.