Dr. Joe Lauer at the University of Wisconsin has written on the subject of increasing input costs for corn growers. This is relevant this time of year since seed sales ads are prominent.
For another graph and more on the subject, please go to his article: Increasing Corn Production Costs Cut Into Profits.
"Since 2003, production costs have been steadily increasing from approximately $2.30 per bushel and $300 per acre to $3.47 per bushel and $531 per acre in 2009. With the exception of chemical costs, nearly all production cost categories (seed, fertilizer, harvesting, equipment and land) have increased since 2003. The most dramatic increases have been with seed and fertilizer. Both productions costs were similar in 2003 (approximately $40-$42) with seed doubling and fertilizer tripling by 2009. Harvesting costs include grain drying, which varies by year and is usually expensive in cool years like 2009."
For another graph and more on the subject, please go to his article: Increasing Corn Production Costs Cut Into Profits.