http://www.backyarddeer.com/homemadedeterrent/

Check out the above link to a blog with several videos of his homemade deer deterrent that he says works for his two and a half acre property. Even better, he tells you exactly how to build one yourself with a list of materials, all very inexpensive or with thing you can scrounge up yourself.

I'm going to try this on my property! Enjoy:)