Six steps for growing continuous corn
"How many of you have been to a corn-on-corn presentation?" asked Paul Gaspar, an agronomy research scientist for Pioneer Hi-Bred International, to those attending a Pioneer Media Event this week.
Not surprisingly, a near-unanimous show of hands shot up.
He wasn't through. "How many?" he asked.
Like farm media members, you've probably sat in on your share of continuous corn sessions on the farm meeting circuit this winter. With corn futures rocketing past the $4 per bushel mark this winter, it's no wonder many of you are considering increasing corn planting.
Granted, you will take a yield hit of around 10% on corn-on-corn compared to corn rotated with soybeans. The good news is that after that first year of continuous corn, the yield decline levels off in subsequent years. And when you combine yield potential plus stratospheric prices, short-term economics point to continuous corn as a profitable option.
"People have been doing corn-on-corn in a lot of places," says Alan Scott, a Pioneer northern market agronomy information manager based in Mankato, Minnesota. "It can be done, but it needs to be thought out. You need to do things before the seed goes in the ground. After the seed goes in the ground, thereâ€™s not a lot you can do."
Some key steps include:
- Select hybrids suited for corn-on-corn.
As with rotated corn, yield potential still ranks as the top hybrid selection factor. However, it's important to combine this with traits such as stand establishment, stalk quality, stress emergence and disease resistance.
Producers who are considering planting more corn may find their selection narrowed, as many popular triple stack hybrids are sold out. However, hybrids well suited for continuous corn are still in supply, says Mike Hellmer, Pioneer agronomy information manager for the eastern market.
- Manage residue.You'll have to battle more residue with corn-on-corn. The increased residue can lower soil temperatures, leading to a cold environment for germination and emerging seedlings. It also can provide a haven for disease and insects.
What to do? Plan on mounting residue managers on a planter that clear a zone for the seed 8 to 12 inches wide. It'â€™s also important to space seed uniformly. If possible, tillage can be used to bury stalks.
"In my part of the world, we're seeing the moldboard plows come out again," says Gaspar, who also is based in Mankato. University of Minnesota studies show a 15-bushel per acre yield increase with moldboard plowing over chisel plowing with continuous corn. That gap widens to nearly 35 bushels per acre when moldboard plowing is compared to no-till under continuous corn.
However, moldboard plowing also has soil erosion considerations and other negative impacts. In some areas, tillage like deep ripping may be more appropriate. Gasper points out that chopping stalks and spreading residue while combining are also important residue management steps.