These charts show total returns for various forms of investment real estate in index form. Over the last 20 years, farmland has returned 70%, timberland 52%, and commercial real estate 0%.
In the period from 1992 to 2001, timberland was the best performer, with returns of 5x the original investment compared to 2.8x for commercial property and farmland. Since 2001, however, commercial real estate has given back all of those gains, timberland 87%, and farmland only 61%.
Farmland has held it's value for most of the last decade; the majority of it's losses have occurred since 2009, along with many other asset classes.