Since corn and soybean prices took off in 2006, there has been much written about how landowners have hiked cash rents via open-bid lease offerings.

Yet, recent research on crop input expenses suggests that farm machinery manufacturers and seed companies have been the undisputed stars when it comes to extracting their share of rising crop revenues.

Using Illinois as a proxy for the Midwest, data from a recent University of Illinois post on non-land crop production costs show that machinery depreciation expense has spiked 175% from $20 per acre in 2005 to $55 in 2012. Seed costs have jumped 151% from $43 in 2005 to $108 per acre in 2012. The expense data comes from Illinois Farm Business Farm Management, a cooperative that collects and analyzes farmer financial records.

Meanwhile, cash rents for Illinois cropland have risen just 64% from $129 per acre in 2005 to $212 per acre in 2012, according to the USDA annual cash rent survey. Rents across the Corn Belt (Illinois, Indiana, Iowa, Missouri and Ohio) have risen 66% over the seven-year period. Even in the Northern Plains (Kansas, Nebraska and the Dakotas), which has seen the greatest farmland price inflation in recent years, cash rents have risen 74% between 2005-2012.

If you have interest in gaining greater insights into market cash rents based on historical relationships between rents as a percentage of crop revenues, see our analysis on Expected Rents. ■