My family farms in Carroll County. Rate all depends on quality of land. There is some that rents for $175/acre all the way to $500+
You could check out dollarsanddirt.com or dreamdirt.com they break it into zones. Not sure what is out for 2015. Think the 2014 average in that area was in the 288$ range. Also they are talking around a 4% drop. Lots of variables. Some still pay in big money for easy access good tillable. Still selling in the 6-9k range.