[Not exactly an answer, but something your post made me realize might be useful to you or other PMs.]
Brettski, while you aren't an agricultural operation, you might want to check out membership in the Illinois Farm Bureau (assuming such a critter exists - do they do any farming in Illinois? :rolleyes: ).
In Ohio this is about $50/year. In addition to some interesting signs basically telling people "This is a farm, manure smells, get used to it" their publications have much useful information on trespassing, liability, and fence/property line law (like how far apart "No Trespassing" signs should be).