I'd use an electric fence to secure an acre. Using a ten foot interval, it get pretty expensive surrounding an acre. These Wirelessdeerfence stakes run $60 or so for three. I'm into the fourth year using most of the original stakes purchased. They are designed to protect small patches or a few plants. We use them at our home in town around a flower bed [7 stakes] and a few next to individual plants, etc..
We have the 14 blueberry bushes, three pear trees and two plum trees secured with the stakes. This patch is next to the pond and deer walk between it and the pond nighty and I've yet to find any damage this year. I use nine sticks here.
