If you haven't heard of the tulip bubble, read about it.
I get tired of hearing "their not making any more of it".
 That being said, if you had the cash, I wouldn't be against buying land, but be prepared for a drop in price during your lifetime, if you can hold on to the right to farm the land.
Dad told me years ago about my maternal Grandfather buying 80 acres of excellent black land near Atlanta, Illinois for $600 per acre in 1928.  Borrowed almost all the money, and lost what he had paid down after the crash.  In 1950, he said the land would again bring $600 per acre, was selling for around $300 at that time.  Now we all know what happened to the price of land in that area.
The trick in investing in anything is to know the future, risk is inevitable.  The secret of predicting prices is to predict often, you will be right for a while, eventually you will be proven wrong.

Summary, buy land and prepare for either an increase or decrease in price.  Either can happen, but are we in a new bubble, or just in the low end of a bigger bubble, and how long will it last?