The University of Illinois has developed a new spreadsheet entitled “Planting Decision Model” to provide some guidelines to help farmers make planting decisions.

"The spreadsheet compares corn and soybean returns by planting date," says Gary Schnitkey, University of Illinois farm management specialist.

"We've built in agronomic functions that give an average or a projected yield for different planting dates. We combine that with the price of corn and soybeans and determine which crop has a higher return on any given planting date."

The spreadsheet is available at http://www.farmdoc.illinois.edu/fasttools/index.asp.

Key factors impacting returns estimates are yield by planting date, harvest-time prices, and non-land costs.

Can farmers switch crops and make money? Schnitkey says probably not.

"Right now those yield functions and very high corn and soybean prices suggest that we wouldn't want to switch in northern and central Illinois until at least the end of May and early June. In southern Illinois, those decisions to switch from corn to soybeans occur in the last week of May, using yield functions that are defaulted within the model," he says.

"Using current commodity prices and costs, switching to more soybeans seems several weeks away," Schnitkey continues. "For northern and central Illinois, corn is projected to be more profitable than soybeans throughout May. In southern Illinois, corn is projected to be more profitable than soybeans through the last part of May. Commodity prices play a key role in return differentials. Current commodity prices favor corn compared to what one would expect with more typical prices."