Many Illinois farmers have been disappointed with 2011 corn-after-corn yields, reporting significantly lower corn-after-corn yields compared to corn-after-soybean yields. So as to provide guidance for 2012 planting decisions, breakeven corn-after-corn yields are calculated for farms in northern, central Illinois with high-productivity farmland (central-high), central Illinois with low-productivity farmland (central-low) and southern Illinois regions. Breakeven corn-after-corn yields are between 24 and 35 bu. lower than corn-after-soybean yields.

Breakeven Corn-After-Corn Yields

Breakeven corn-after-corn yields are calculated in Table 1 and require soybean returns, corn-after-corn non-land costs and corn price information. Calculations are shown for northern Illinois. In northern Illinois, soybean returns are projected at \$342/acre (54-bu. soybean yield x \$12 soybean price - \$306 non-land costs). This soybean return, along with corn-after-corn non-land costs and corn price, are used to find the breakeven corn-after-corn yield. For \$542/acre of non-land costs for corn and a \$5.50 corn price, the breakeven corn-after-corn yield is 161 bu./acre (161 bu. = (\$342 soybean return + \$542 corn non-land costs) / \$5.50 corn price). This means that corn-after-corn with 168-bu. yield will give the same return as soybeans with 54-bu. yield.

The 168-bu. breakeven corn-after-corn yields for northern Illinois is 29 bu. below the 190 bu. projected yield for corn-after-soybeans. This suggests that the breakeven yield drag between corn-after-soybeans and corn-after-corn is 29 bu. in northern Illinois. Calculations in other regions indicate:

• The breakeven corn-after-corn yield in central-Illinois with high productivity farmland is 163 bu./acre, 35 bu. below the 198 projected corn-after-soybean yield.

• The breakeven corn-after-corn yield in central Illinois for farms with low-productivity farmland is 160 bu., 24 bu. below the 184-bu. projected corn-after-soybean yield.

• The breakeven corn-after-corn yield in southern Illinois is 143 bu./acre, 24 bu. below the 161-bu. projected yield for corn-after-soybeans.

Obviously these break-evens vary with differing prices, yields, and costs. Farms will have different yields and costs; hence, breakevens vary across farms.