Here’s what one farmer reported: “I need every soybean I can get this fall. How can I determine field loss for soybeans after the combine passes through the field?”

The panel of Indiana certified crop advisers offers suggestions. The panel includes Betsy Bower, agronomist with Ceres Solutions, Terre Haute; Jamie Bultemeier, agronomist and corporate sales director for A&L Great Lakes Labs, Fort Wayne; and Steve Gauck, sales agronomist for Beck’s, Greensburg.

Here are their recommendations.

Bower: To understand harvest losses, start with an understanding of current field loss of soybeans before harvest. Make a frame that is a foot square. It can be made out of any material, but the lighter the material, the easier it is to take to fields.

To determine current field loss, go to an area in front of the header that isn’t harvested. Put the frame on the soil surface and count number of loose beans in pods and beans on the ground. Do this in at least four spots across the header. This is the background field loss.

Gauck: Start by checking your combine before harvest. More grain is lost at the head than through the back of the combine. Be sure you have a sharp cutter bar with all guards in place.

Bultemeier: Checking for combine grain loss is as detailed or simple as you make it. On average, there are 180,000 soybeans in a bushel. Dividing that by 43,560 square feet in an acre, you get just over four soybeans per square foot behind the combine equaling 1 bushel of grain loss per acre. (Editor’s note: Gauck also recommends using 4 beans per square foot as 1 bushel of loss. Bower uses 3.5 beans per square foot.)  

Bower: Once you have background loss, run the combine and count again. Count not only soybeans on the loose beans and soybeans on the ground, but also count beans in pods still attached to the stem but not gathered into the combine. This is loose stalk loss. Then count all the beans in the pods of the plants that weren’t cut with the header — that’s lodged stalk loss. Also count the beans in the pods of loose stubble, known as stubble loss.

Determine the average loss of each category and subtract the current background field loss. This will help you understand where adjustments need to be made.

Bultemeier: If the loss is above 1% to 2%, further investigation is warranted. Before making combine adjustments, find out where the loss is occurring. Harvest another area, stop the combine, raise the head and back up more than one combine length. Count beans in standing crop, as Bower noted. Those preharvest losses can’t be reduced. Also count beans left on the ground under the combine. Those are header losses and need to be addressed with feeder and feeding adjustments.

Gauck: Following on that idea, do you need to change settings in the combine? Or is it settings and reel speed on the head that need adjusted?

Bower: Make one combine adjustment at a time and determine harvest losses again. Once the combine is set, monitor harvest losses periodically. Changes in growing conditions, varieties and pest issues can alter harvest losses between fields.