Production Blog

JEFFERSON CITY, Mo. (DTN) -- As the 2024 season enters the homestretch and farmers begin to reap what they have sown, it's easy to get impatient. But budgeting a little extra time to ensure that harvest equipment is performing at peak efficiency is critical to maximizing yield and minimizing field losses.

According to a University of Georgia study, if just two corn kernels are left behind per square foot of harvested field, that is equal to the loss of one bushel per acre. Fail to get just one average-sized ear through a 12-row header every 15 feet? That's also equal to one lost bushel.

Seemingly similar small numbers in soybeans also add up to substantial losses quickly. Extension specialists at North Carolina State University determined that it only takes four average-sized soybeans left unharvested per square foot to equal one lost bushel.

In both crops, losses may occur both prior to and during harvest. Pre-harvest losses are highest in corn when crop condition deteriorates while awaiting acceptable harvest moisture, resulting in dropped ears. Scout fields and prioritize the harvest of fields where standability has become suspect. During harvest, losses can occur at several steps in the process, beginning at the header and continuing through threshing and separation.

As a starting point, prepare the combine with the settings recommended by the manufacturer. Then, adjust as needed to the condition of the crop as the day progresses. The more often adjustments are made, the fewer the harvest losses.

KERNEL KNOWLEDGE

An Iowa State University Extension publication on profitable corn harvesting lists these combine adjustments for farmers to consider:

-- Adjust gathering snouts so that under normal conditions, they just touch the ground. If plants are lodged, let snouts float on the ground and reduce ground speed as needed.

-- Set snapping roll spacing according to stalk thickness. Set the stripper plates as wide as possible without losing ears or shelling kernels off the ear. To prevent wedging, set plates slightly narrower in the front than in the back. Narrow the plates so that small-diameter ears are not pulled through and lost.

-- Set ground speed as fast as possible based on the condition of the crop. Set snapping rolls relative to ground speed. When set too fast, rolls increase the impact of the ear on the stripper plates, resulting in ear bounce and causing kernels to be shelled and lost.

-- Set the cylinder/rotor speed to an rpm that will shell the grain within acceptable loss levels (less than 1% in good-standing fields). Excessive speed can cause grain damage, while kernels can remain unshelled if threshing is too gentle. To reduce unthreshed losses without increasing grain damage, try decreasing the concave clearance before increasing cylinder/rotor speed.

-- Set concave clearance to avoid breaking the cobs excessively. This can lead to kernels left on cob fragments. For best results and minimal threshing losses, cobs should only be broken into three or four pieces.

-- Set sieve and fan settings to optimize separation and cleaning. Kernels can be lost if the fan speed is too high, but excess foreign material can be retained in the grain if the speed is too low.

SOYBEAN SUGGESTIONS

According to N.C. State Extension specialists, gathering losses account for more than 75% of overall soybean losses at harvest, so proper header adjustment and operation is crucial. Here are some items to remember:

-- Maintain ground speed at 3 mph or less. Indications that ground speed is too fast include long stubble, uneven cutting height and shatter losses due to knife stripping.

-- Operate the cutterbar as close to the ground as possible. A floating, flexible cutterbar with automatic header height control will keep losses at low levels.

-- Keep knife sections sharp. Make sure guards, wear plates and hold-down clips are in good condition and properly adjusted. Narrow-section knives reduce shatter and may permit slightly higher ground speeds.

-- Operate reel about 25% faster than ground speed. Position reel axis 6 to 12 inches ahead of cutterbar. Bats should enter the crop only enough to gain control.

-- Operate the cylinder at the lowest speed that still allows for complete threshing. This will reduce bean splitting. Check and adjust as crop and field conditions change throughout the day.

Formulas are available to help farmers determine the extent of pre-harvest losses as well as header losses and threshing and separation losses. Taking the time to assess your combine's performance and reduce harvest losses means more grain in the tank and, ultimately, a more profitable season.

Here are links to university resources explaining how to estimate and reduce harvest losses:

-- https://cropwatch.unl.edu/…

-- https://dr.lib.iastate.edu/…

-- https://extension.uga.edu/…

-- https://content.ces.ncsu.edu/…

Jason Jenkins can be reached at jason.jenkins@dtn.com

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