This report comes from the USDA, and tracks changes in the prices received by farmers and in prices paid by farmers. It doesn't get a lot of respect from the equity markets - the contents of this report are typically the things getting excluded from the "core" inflation measures so beloved by various analysts and agencies - but this has a significant impact on GDP. Let's face it, even if food prices aren't being tracked in inflation costs, rising food prices will limit disposable income for other purchases.
So, let's have a look at the March report. The All Farm Products Index of Prices Received by Farmers hit 174%, up 400 bps (2.4%) from February and 3300 bps (23%) from March 2010. The Crop Index is up 100 bps (0.5%) from February, and the Livestock Index is up 700 bps (4.9% from February). Meanwhile, the Index of Prices Paid for Commodities and Services, Interest, Taxes, and Farm Wage Rates hit a level of 199%, up 200 bps (1%) from February and 1900 bps (11%) from March 2010.
That level, by the way, is essentially looking at how much each of those indices has increased since the base period of 1990-1992. So yes, that means that farmers are earning 174% more than they did 20 years ago, and they're paying 199% more on their expenses. On average.
The actual report is 43 pages long, with a lot of detail about changes in crop prices, livestock prices, and food commodities. Have a look at it. It's... educational.