Planting Corn After Corn Demands Top-of-Game Management

Pioneer agronomists offer best management practices to help maintain yields

Growers planting corn after corn need to be on top of their game to maximize yields, compared to traditional crop rotation systems. Agronomists from Pioneer Hi-Bred, a DuPont business, say growers’ success depends on using best management practices across the board in: field selection; soil temperature; hybrid selection; pest management; fertility; and residue management.

“Despite potential yield reductions with a corn-after-corn crop system, the economic advantages of growing corn after corn have outweighed the benefits of rotation for some growers,” says Steve Butzen, Pioneer agronomy information manager.

Field selection
The most successful corn-after-corn producers begin with highly productive fields, then manage these fields carefully to minimize compaction, handle excessive residue and maintain soil fertility.

Butzen recommends growers choose fields for corn-after-corn production that have historically high corn yields, good drainage and medium-textured soils with ample water-holding capacity.

Soil temperature
When it comes time to plant, corn-after-corn fields present a more adverse environment for corn seed and seedling.

“Don’t plant corn-after-corn fields too early - especially when soils are below 50 degrees and warmer weather is not in the forecast,” says Butzen.

Hybrid/technology selection
Some hybrids are better equipped for corn-after-corn situations than others. Butzen says Pioneer rates its hybrids for stress emergence, high residue suitability, resistance to leaf and stalk diseases, and stalk and root strength. All of these ratings are available to Pioneer customers to help determine which hybrids work best in corn-after-corn fields.

Growers should always be sure to:

*Select hybrids with proven performance under the diverse environments and stresses their field may encounter.
*Select hybrids with above-average drought tolerance.
*Select hybrid maturities that match planting date and seasonal growing degree units, accounting for cooler soils and slower emergence under corn residue.
*Choose the highest-performing genetics with the defensive traits required for this production system.

Pest management
Butzen says Pioneer offers several plant and seed technologies for controlling insects and diseases that increase in corn-after-corn production systems. He says effective control measures are critical for corn rootworm (CRW), since CRW pressure tends to be highest in the second and third years of continuous corn.

“For CRW control, choose from hybrids with a transgenic trait or an insecticide seed treatment or apply a granular soil insecticide,” Butzen says. “The appropriate option depends on the level of CRW damage expected in the field and which other insects need to be managed.”

Pioneer offers plant and seed technology options including Pioneer® brand hybrids with Herculex® XTRA insect protection or insecticide seed treatments for low to moderate CRW infestations, Herculex XTRA offers a combination of the Herculex RW and Herculex I traits to guard against CRW and a broad range of above-ground insects.

“Western, northern and Mexican corn rootworms are all controlled by Herculex RW,” Butzen explains. “The Herculex I gene protects against corn borer, black cutworm and western bean cutworm. In addition, it suppresses corn earworm, and controls fall armyworm and several other pests. These are important insects to monitor and manage in a corn-after-corn rotation.”

Secondary soil insects such as wireworms, seed corn maggots and white grubs can be controlled effectively by insecticide seed treatments.

On the disease front, Butzen notes that seedling disease problems caused by Pythium, Fusarium, Rhizoctonia and other pathogens have increased throughout the U. S. These diseases reduce stands and yields in corn-after-corn fields.

“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.

Fertility management
Soil fertility in corn-after-corn production should be based on thorough soil testing and local Extension recommendations. Soil tests are needed to determine soil pH and existing levels of phosphorous and potassium. Soil pH should be at 6.2 or above.

“In high residue fields, consider using 50 pounds of starter nitrogen to give plants a faster start,” says Butzen.

“In all fields, consider splitting nitrogen applications if possible. This can reduce nitrogen losses and help ensure corn plants have adequate nitrogen throughout the season.”

Residue management
A corn crop produces more than twice the amount of residue as a soybean crop. Excessive corn residue can result in cooler soil temperatures and higher soil moisture at planting.

To counter these problems, Butzen says growers should plan to manage corn residue effectively at planting. The goal is to clear residue from the row area.

“Row cleaners, coulters or other residue management attachments on the planter can help create a more suitable environment in the seed zone for more rapid germination and emergence,” Butzen says. “In addition, growers should distribute residue evenly at harvest. Tillage in the fall can help build a good seedbed, but plan to have adequate labor and equipment if corn acres are increasing.”

Butzen says research studies have shown tillage systems can have a significant impact on the relative yield of corn after corn versus corn after soybeans. Clearing residue often from over the row is important for best yields under no-till.

For further information on early corn planting, contact your local Pioneer sales professional. In addition to your sales professional, Pioneer offers a network of agronomists to provide assistance.