Emerson Nafziger, University of Illinois Extension agronomist, encourages growers not to lose heart because disappointing yields come down to a lack of water during the critical grain-filling period.

While continuous corn growers may still see 5-10% lower average yields, he offers tips for factors that can be controlled:

*Consider other rotations.Nafziger says a corn-corn-soybean rotation may offer a good alternative with yields of first-year corn the same as yields in a corn-soybean rotation. Yields of second-year corn were better than yields of continuous corn.

"One added benefit to the corn-corn-soybean rotation over corn-soybean rotation is that soybeans yield about 5% more following two years of corn versus following one year of corn," he says.

*Evaluate nitrogen management. While corn following corn typically needs more nitrogen (N), Nafziger says how much management should change is unclear. Getting N closer to the seed might help, but sound N management, including the right timing, right form and right rate, remain the most important factors.

*Don't fix what isn't broken. Nafziger's research shows that in either rotation, corn responds similarly to planting date and plant populations. While he has not identified hybrids that do consistently better in corn-following-corn, he says stresses must be considered.

"Residue-related diseases can be more of a challenge, especially when there is enough water, and water stress is less of a factor," he says. "Ask seed reps for stress-tolerant hybrid advice."

*Determine tillage needs. Illinois researchers compared no-till to tillage with and without residue removal. No-till with some residue removal yielded as much as conventional tillage. Nafziger's advice is to accurately assess soil conditions before and during spring fieldwork to see if operations compromise the ability of roots to penetrate, should it become dry later.