Calculations and data collection in Illinois for the years of 2000 to 2010 shows that corn on corn yields needed to be 3.3 times the soybean yield for farmers to break even compared to being in a corn-soybean rotation, as reported by Greg Scheer, associate editor of Doane’s Agricultural Report, in interpreting data released by Gary Schnitkey, Department of Agricultural and Consumer Economics at the University of Illinois.

It’s common for farmers to notice a yield drag for corn after corn compared to corn following soybeans, but corn yields don’t continue slipping in a non-rotation situation. Soybean and corn market prices are the main factors influencing the yield necessary from a corn-on-corn planted field to beat the return from a corn-soybean rotation.

Scheer wrote the following: “The break-even for corn-after-corn yields relative to soybean yields is low historically. For northern Illinois, the 163 bushel break-even corn-after-corn yield is 3.0 times the 54 bushel per acre projected soybean yields. From 2000 to 2010, the corn-to-soybean break-even ratio has averaged 3.3, meaning corn yields had to be 3.3 times higher than soybean yields to break even. This relatively low ratio currently suggests that market signals are favoring corn production over soybean production even with a significant corn-after-corn yield drag. Also, some research has shown little or no further yield drag from subsequent years of corn-after-corn. Yields take a hit the first year and then stabilize.”

To go directly to Schnitkey’s extensive report click here.