With the last few years of high corn prices, continuous corn rotations are becoming more common. But, using a corn-on-corn system brings a new level of challenges.
Wade Thomason, assistant professor of grain crops at Virginia Tech, provides some key considerations you should have when planning for next year's corn crop.
Pick the Right Hybrid
Even with the almost endless option for corn hybrids, Thomason says you should ensure a few specific characteristics are in the mix. "For us, a lot of it comes down to hybrid selection,” he says. "Disease resistance should come up in the importance level.”
He says with the stronger likelihood of diseases carrying over on the corn residue, having a hybrid that is resistant to grey leaf spot, corn rootworm or other soil-borne pathogens will help keep yields high.
Choose the Right Field
Thomason says in his area, both systems of grain and silage corn production use corn-on-corn systems. He says, depending on the overall goals for a field, this may or may not be the best planting method to use.
"It really comes back to that it [a continuous corn rotation] works better on the better land,” he says.
Pump Up Your Nitrogen
Thomason says in studies at Virginia Tech, yield losses ranging from zero to 15% have occurred in corn-on-corn rotations. To help combat this, he says you may need to apply 20 to 30% more nitrogen.
The reason for the high nitrogen loss, Thomason says, is because the large amounts of residue left in the field tie up the nitrogen and immobilize it. So, the next round of corn cannot benefit from the nitrogen.
Plan Your Herbicide Attack
"In continuous corn, you limit yourself in the options for herbicides,” Thomason says. He says herbicide resistance can occur, if you use the same herbicide several years in a row.
"It's a good time to sketch out a plan,” he says. "Talk with your chemical supplier to see what's available to try.”
For More Information