DES MOINES, Iowa, Feb. 20, 2009 - Corn rotated after soybeans generally out yields corn following corn, but there's help for growers choosing corn-after-corn rotations through modern crop technologies, say crop production experts from Pioneer, a DuPont business.
The "rotation effect" is an unexplained benefit that results in yield increases for corn following soybeans, compared to corn following corn.
"The rotation effect varies depending on growing conditions," says Steve Butzen, agronomy information manager at Pioneer. "When yield potential is low due to tough soils or lack of rain, the benefit of rotation is highest."
Another benefit with rotating corn and soybeans is the potential to lower the amount of nitrogen needed," says Paul Gaspar, agronomy research scientist for Pioneer. "In years with excess rainfall that leads to nitrogen losses, this advantage may be even more important."
"The less nitrogen growers have to apply the better for time and input costs," Butzen says. "Rotation also helps control diseases and insects. Continuous corn is a host to many of the corn pests growers have to face."
Also in corn after corn, the plant's root system may be limited due to corn rootworm feeding or soil compaction. This leads to increased plant stress and yield loss in years when demand for soil moisture is high.
"Despite potential yield reductions with a corn-after-corn system, the economic advantages of growing continuous corn have outweighed the benefits of rotation for some growers," says Butzen. "The most successful corn-after-corn producers start with highly productive fields with high water-holding capacity and good drainage. They then manage these fields carefully to minimize compaction, handle excessive residue and maintain soil fertility."
Hybrid selection is another key to corn-after-corn success. Pioneer offers the latest high-performing hybrids that can handle tough conditions.
"Although corn after corn is a more challenging production environment, Pioneer has hybrids and traits that help mitigate the risks," Gaspar says. "Select hybrids with a good disease package, corn borer and corn rootworm resistant traits, and good standability ratings. In addition, Pioneer provides stress emergence ratings and high residue suitability ratings for all corn hybrids. These ratings are assigned specifically to help determine which hybrids work best in corn-after-corn fields."
Seed treatments also significantly improve seedling health and should be considered, especially when planting early. Pioneer uses a seed treatment that includes Dynasty® fungicide for all corn hybrids. Dynasty has increased activity against several soil fungi that cause corn seedling diseases, says Butzen.
"Pioneer sales professionals can help you choose the right products, traits and seed treatments if you plant continuous corn" Gaspar surmises. "There are many more options now than there were just 10 to 15 years ago."
Pioneer Hi-Bred, a DuPont business, is the world's leading source of customized solutions for farmers, livestock producers and grain and oilseed processors. With headquarters in Des Moines, Iowa, Pioneer provides access to advanced plant genetics in nearly 70 countries.
DuPont is a science-based products and services company. Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture and food; building and construction; communications; and transportation.