Measuring soybean harvest losses

Measuring soybean harvest losses periodically is essential to determine if combine adjustments are necessary and effective.

September 6, 2012 - Author: Mike Staton,

Equipment adjustments play a significant role in reducing soybean harvest losses. In order to make the proper adjustments, the combine operator should stop the combine periodically and check the amount and type of loss that is occurring. Since 80 percent of the losses occur at the header, this article will focus on measuring gathering losses.

The first step is to build a frame having an inside area of 1 square foot. I use 1-inch PVC pipe. Next, stop the combine in a representative area of the field and back up 10 to 15 feet. Use the frame to count the number of beans on the ground in the harvested area in front of the header. Take at least four counts across the entire length of the header. For each count, record the following information.

  • Shatter loss. Count all the loose beans and beans in loose pods in the standing crop ahead of the combine and subtract this number from the number of loose beans and beans in pods you find in the harvested area.
  • Loose stalk loss. Count all the beans in pods attached to plants that were cut but not gathered into the combine.
  • Lodged stalk loss. Count all the beans in pods attached to plants that were not cut.
  • Stubble loss. Count all beans in pods that remain on the stubble.

Determine the average losses in beans per square foot for each category and divide by four (four beans per square foot equals one bushel per acre). Use this information and the recommendations covered in the accompanying article, Pay close attention to reducing soybean harvest losses this fall, to adjust your combine settings.Make one adjustment at a time and stop periodically to evaluate your progress toward reducing harvest losses to 3 percent.

Gathering loss measurement example:

Sample Area

Sample 1

Sample 2

Sample  3

Sample 4
















The average gathering loss in this example is 8.5 beans per square foot which equals 2.2 bushels per acre.

(8 + 8 + 9 + 9) ÷ 4 = 8.5 beans/ft2

8.5 beans/ft2 ÷ 4 = 2.1 bushels/acre

For more information on reducing soybean harvest losses, join us September 20 for a Soybean Harvest Equipment Field Day and Plot Tour.

This article was produced by the SMaRT project(Soybean Management and Research Technology). The SMaRT project was developed to help Michigan producers increase soybean yields and farm profitability.SMaRT is a partnership between MSU Extension and the Michigan Soybean Checkoff program.

Tags: agriculture, field crops, msu extension, soybeans

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