When growers consider corn after corn, they should be aware of issues that may require more-intense crop management, says Ryan Clayton, a DuPont Pioneer field agronomist based in Waukee, IA. "Residue management will be critical," says Clayton. "This is especially true with no-till production because growers must handle residue with harvest and planting activities."
Establishing good early-season plant stands is vital. Clayton notes growers will often see a drop in average yield with the first year of corn-after-corn production. That effect tapers off in subsequent years of continuous corn.
There may also be an increase in disease pressure, especially foliar diseases, as pathogens remain in the residue of the previous year's plants. Pressure from pests such as corn rootworm also may be heavier following corn. Growers should consider hybrids that contain adequate disease and insect tolerance.
Growers must also remember they can't take the normal credit for nitrogen (N) fixation that soybeans provide. Growers will need to gear their fertility programs to their anticipated yield levels. Clayton suggests a split application of N and, where possible, side-dressing the crop.
After a drought year, moisture may be a critical limitation for newly planted corn. Fields that contained corn in 2012 may start off with less soil moisture than those that held soybeans.