A number of systems including chisel plow, disk, ridge-till, and no-till have the
potential for leaving 30% or more residue cover following corn, sorghum, small
grains, and in some cases, soybeans. However, any planting system (including
no-till), if not properly managed, can leave significantly less residue cover than
needed for adequate soil protection.
The tillage and planter/drill-related factors discussed here greatly influence
residue cover and should be considered when planning to meet crop residue
management goals.
Number of operations
Make every effort to limit the number and intensity of field operations.
Speed of operation
Slowing down during field operations can save residue. Depending on the situation,
slowing down 2 mph can save 10-20% more residue. Studies show chisel plow-
ing corn residue at 2-3 mph instead of 5-6 mph can save over 10% more residue.
Disking soybean stubble at 3-4 mph instead of 6-7 mph can increase cover by
as much as 15%.
Depth of operation
Generally, the shallower the tilling, the less residue lost. For instance, disking soybean
stubble at 3 inches instead of 5 inches deep leaves 15% more residue. Chisel plowing
cornstalks at 5 instead of 7 inches results in 10% more cover.
Angle of operation
Most modern equipment for primary tillage like chisel plowing and disking is
designed for "high clearance." That means there's no longer a need to angle
field operations. Tilling in the same direction instead of at an angle to old rows
can leave significantly higher levels of residue cover.
Soil-engaging tools
Type of soil-engaging tool used is also
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important. For example, in non-fragile crop residues, using sweeps instead of chisel
plows can leave as much as 35% more residue.
Many attachments, like this residue manager, can improve planter performance.
Row-cleaning devices
Row cleaners (attached to planters or drills) are designed to move crop residue
from the row to provide a cleaner seedbed, more control of seed depth, and
more uniform soil warming. Such attachments usually include double-disc furrowers plus
horizontally mounted discs for ridge-till systems, row-cleaning brushes plus spoked or
spider wheels for no-till and some conventional systems.
Midwest research indicates row
cleaners can reduce surface residue cover as much as 20% after planting into corn and
soybean residue. They are effective when set to move only residue, but deeper
settings will move a considerable amount of soil. The result can be grooves that hold
moisture and lead to wet planting conditions and/or soil erosion in the row.
This photo shows how different tillage systems affect crop residue cover. (L-R:)
No-till, chisel, disk, moldboard plow.
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