September 1, 2009
Growers who bale corn residue have a good reason to chop corn stalks. But everybody else could just as well skip that trip across the field and save about $8/acre.
That's one piece of cost-cutting advice from Midwest Extension experts.
“We want growers to evaluate each operation and ask, ‘Is it making me money?’” says Gary Zoubek, University of Nebraska Extension educator in southeast Nebraska.
In many parts of the Corn Belt, it's traditional to manage corn residue by chopping or shredding it after harvest, says Mahdi Al-Kaisi, Iowa State University Extension agronomist. “But there are better management options,” he says. These include:
Strip-tillage
Using residue managers on the planter to push residue off the seedbed
Properly weighted planter and down-pressure springs to maintain the correct planting depth
Carefully calibrated combine to ensure uniform residue distribution
Shredding residue costs from $4.25 to $13.50/acre, according to a 2008 custom rates survey by the Nebraska Extension Service. Iowa State University estimates are similar.
In addition to expense, fall stalk chopping has environmental costs, Al-Kaisi adds. Compared with standing stalks, light, loosely chopped residue is more likely to blow away or wash off, leaving the soil unprotected. “And our research shows that chopping residue doesn't speed decomposition,” he says.
Research across the Corn Belt has found no economic advantage for shredding cornstalks, Al-Kaisi and Zoubek say. In 2004 and 2005, for example, several southeast Nebraska growers compared fall cornstalk shredding vs. not shredding. The replicated strip trials were performed at multiple locations on irrigated, corn-on-corn fields.
Fall shredding did not increase corn yields, Zoubek says.
RON MAKOVICKA participated in Zoubek's stalk shredding research a few years back. He raises corn and soybeans in a three-year sequence on very productive irrigated ground in York County. He ridge-tills and had always shredded corn stalks after harvest to help manage all the trash. But “it was costing us to shred,” he says.
In 2005, Makovicka did side-by-side comparisons of shredding and not shredding in five pairs of replicated strips across an entire field. The strips with the standing stalks actually yielded slightly better than the strips with shredded residue, he says, possibly because they “caught more snow and conserved more moisture.”
So Makovicka quit shredding corn stalks in the fall. He continues his usual practice of going over the corn residue with a rotary stalk chopper right before planting in the spring, to prepare the ground. The spring field operation is faster and cheaper than fall shredding, he says, and it's better for erosion control.
“Every year, if there's something new, some way of cutting costs, we're willing to try it if it makes sense for our operation,” Makovicka says. This season, for example, he lowered soybean populations from 160,000 seeds/acre to 140,000.
“The key message is to have producers think about all the practices they do,” Zoubek says. “Evaluate each tillage operation and determine if the benefits outweigh the costs or expense,” he says.