On Friday, I left the rolling hills of Columbia, Mo., and headed northwest, to the flat farmland of Saline County. The purpose of the drive was to get a look at the priciest cropland in Missouri for a story I'm doing on how investors with no connection to farmland are increasingly interested in buying acreage in the Midwest. I had heard from farmers and real estate brokers that cropland values were at all-time highs in the Corn Belt, and incredibly many of the tracts of land are being paid for in cash.