Library Categories


Don’t leave beans, bucks behind

Soybeans don’t make money unless they make it into the grain bin. With the 2010 soybean harvest completed, hindsight and a simple yield loss monitoring tool can help producers hone in on their harvest efficiencies for the next growing season.

University of Nebraska Extension educator Tim Lemmons says that typical soybean harvest losses of 10% occur each year in the Midwest, with some losses reaching 25%.

At a glance

Yield losses at harvesttime can run up to 10% to 25%.

Extension educator says acceptable harvest losses are 3% or less.

Use a 10-square-foot metal frame to measure losses.

Lemmons recommends that producers field check for losses next harvest season, to see where they fit into that range. He suggests the following step-by-step procedure for checking field harvest losses.

While operating at harvest speed, stop the combine and back up 15 to 20 feet.

Take a metal frame measuring 10 feet square or measure and mark 10 feet square on the ground about 20 feet behind the combine.

Count all the soybeans found in the frame. Forty beans equals a loss of 1 bushel per acre.

Move the frame in front of the combine and measure the preharvest loss in the same way.

Measure shatter loss by counting all loose beans and beans in detached pods. (Acceptable loss is 0.75%.)

Measure stubble loss by counting all beans in pods attached to stubble that is partially cut but not gathered in the combine. (Acceptable loss is 0.75%.)

Measure lodged loss by counting beans in pods in harvest area attached to stalks that were not cut. (Acceptable loss is 0.50%.)

Measure loose loss by counting beans in pods attached to full stalks cut but not gathered in the combine. (Acceptable loss is 0.50%.)

According to Lemmons, preharvest loss should be 0.25% or less and combine loss should be at 2.75% or less, to add up to a total loss of 3% or less. If a 10-foot metal frame is too cumbersome, he says farmers could use a 1-square-foot frame, counting lost beans within that area and multiplying that number by 10 to arrive at the total loss figure.

With a 1-square-foot frame, every four beans found equals approximately 1 bushel of loss per acre; whereas with a 10-square-foot frame, 40 beans equals a 1-bushel-per-acre loss.

“There is a greater potential for bias in placement” with the 1-square-foot frame, Lemmons says.

“A producer may unintentionally place the frame in a position that may not be representative of the total platform loss. Using a 10-square-foot frame that has a width the same as the platform offers an opportunity to examine overall loss across the entire harvest cut,” he notes.

He says that combine yield monitors only display the approximate amount of loss from separation and threshing, and do not take into account preharvest losses, which can be substantial. Lemmons says that 80% to 85% of harvest loss occurs in front of the combine in the form of shattering, lodging and failure to cut, and gathering loss, which includes soybeans that are cut but not fed into threshing.

“While it is improbable that a producer is capable of minimizing harvest loss to zero, close monitoring of harvest operations and regular adjustment when necessary have demonstrated the potential to recapture $57.50 to $86.70 in revenue from a field with 60-bushels-per-acre yield potential,” he says.

For more information on monitoring and preventing yield losses during harvest, contact Lemmons at 402-370-4061.

Timing is crucial

Don’t wait for soybeans to become too mature at harvest. That’s the key to preventing harvest losses next year, says UNL Extension educator Tim Lemmons.

“Waiting too long after maturity is realized results in increased shatter loss,” he says. “Preharvest loss may be minimized by making sure that harvest operations are conducted when 95% of the field has reached maturity,” which is when the soybean plants reach proper maturity color and moisture content for the specific variety planted.

“Harvesting before maturity is realized results in green soybeans that may not separate during threshing,” Lemmons says.

Watch the reel speed, too, he says. “A reel that rotates too fast may cause increased shatter loss, while a reel that is rotating too slowly may not effectively gather plants during cutting.” Reel speed should be about 25% greater than ground speed.

Lemmons says that farmers should also check the cutting bar for broken or dulled teeth and guards, and should check their sensors regularly to make sure that automatically adjusting bean platforms are responding properly to field conditions.


MEASURING THE LOSS: Tim Lemmons, Extension educator, explains how to monitor harvest yield losses by using a metal frame in the field during harvest and counting soybeans left on the ground inside the frame in front of and behind the combine.

This article published in the December, 2010 edition of NEBRASKA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.