We have a few running through fields and one that will be installed this summer.  You can decide if you want to fight it or not.  If you accept it is coming, the first thing I would do is sit down and design a drainage plan with a very large main running about 5-6' deep around where the proposed route is installed.  In Iowa, they are required to be at least 1' beneath the a tile line.  

The one coming this summer started with 4' of cover.  After some landowner negotiations it changed to 5' everywhere.  Our's is paying x amount for the easement and prorated crop damages for 5 years.  100% this year, 80% next and so on.  It is prorated over 5 years crops, but will all be paid this year.