Residue: Too much of a good thing
Farmers are getting slammed with a triple whammy (or too much of a good thing) when it comes to crop residue, particularly that from corn.
Bt hybrids bred to withstand lodging and the increased use of foliar fungicides have resulted in stalks that resist decomposition.
Ever-increasing plant populations and corresponding fertilization programs are boosting both yields and the amount of stover a crop produces.
Compounding both situations is the trend to more corn-on-corn. The result is a bounty of crop trash that, if left unattended, can spell trouble next spring.
“Generally, excess residues tend to be a problem in the northern U.S. and Canada. Warmer temperatures in the south promote winter degradation,” explains Steven Butzen, Pioneer Hi-Bred.
Adam Heimer of John Deere cautions there is no single solution for dealing with increased residue. “It starts with the combine doing a good job of processing trash and a strategic tillage program,” he says.
On the other hand, University of Nebraska ag engineer Paul Jasa says crop residue disappears too fast for his preferences. “In terms of catching moisture (in snowfall) and stopping soil erosion, residue is an asset,” he says.
Following are six management tips to help you tame your trash.
1. Aim for 80% head-width distribution
Even distribution of trash behind the entire width of a combine's head is the key.
An arsenal of tools can be brought together to battle against excessive residue. Two such tools are full-bodied residue-management systems and more aggressive heads. Discover a step-by-step guide to keeping choppers fine-tuned on page 35. Corn heads that process (chop, chew up, or crush stalks) are discussed on page 36.
“When it comes to residue management at the combine, the key is to spread it evenly behind the entire width of the head or platform whether running in corn, soybeans, or small grains,” recommends Kim Cramers of John Deere.
Situations where a narrow strip or a windrow of residue is being left directly behind the combine are a recipe for trouble next spring, warns Bob Wolkowski, a University of Wisconsin agronomist.
Wolkowski uses a rule of thumb for distribution where residue is spread across a minimum of 80% of the width of the head. If that is not occurring, he recommends upgrading the combine with a more aggressive residue chopper.
“Generally, farms don't spread wide enough,” says Phil Needham of Needham Ag Technologies. “You've absolutely got to spread evenly as well. We've seen examples where a heavy band of residue right behind the combine can cause a decrease in stands by 20% to 30% in no-till situations.”
Options abound when it comes to residue systems on combines. Some manufacturers are now offering three system options, ranging from the traditional beater spreaders (horizontal spinning disks) up to aggressive attachments with chopping knives that can be adjusted to conditions.