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Minimizing Combine Grain Loss

As a combine operator, it’s tough to know just how many bushels are being left behind in your fields. With harvest being such a hectic time of year, it’s critical to consider potential harvest losses and take time to make necessary adjustments. 

Every bushel of corn or soybeans left behind by the combine represents a loss in potential profits. While harvest losses cannot be completely eliminated, mechanical losses should be kept to a minimum. Harvesting at the right moistures, along with the appropriate combine adjustments, may reduce loss to a 1-2 bushel per acre (bu/A) range. 

Soybean harvest loss
Count the number of soybeans on the ground inside a 1 foot square, and replicate the process several times throughout the field. This will help determine the average number of soybeans lost per square foot. When counting soybeans on the ground, 4 soybeans per square foot = 1 bu/A yield reduction. 

Most soybean harvest loss occurs at the gathering unit of the combine between the header and standing soybean plants. This loss is often due to pod shatter. Losses due to shattering may be reduced by harvesting soybeans as quickly as possible when moisture levels reach 13%-14%. The combine ground speed should be reduced to 3 mph or less, and the reels should be operating at 25% faster than the ground speed.

Corn harvest loss
One source of corn yield loss is due to dropped ears. Determine total ear loss by counting the number of dropped ears in an area equivalent to 1/100th of an acre. When planting in 30” rows and harvesting 6 rows at a time, 1/1000th of an acre sample would utilize 29 feet of rows. When harvesting 8 rows at a time, you would utilize 22 feet of rows for a 1/100th acre sample. Each full size dropped ear in your sample area would represent a 1 bu/A yield loss.

To determine corn yield loss from scattered kernels on the ground and kernels still attached to the combined cobs, utilize the same 1 foot square used in the soybean example. Count the number of lost corn kernels within the 1 foot square. Replicate this process several times throughout the field to obtain an average lost kernel count. Every 2 kernels of corn left on the ground represents 1 bu/A yield reduction. 

Proper combine settings will allow you to maximize income by reducing harvest losses while decreasing volunteer corn issues that could crop up the following year. Minimize ear loss by setting the snapping rolls to fit the stalk width, and running the snapping rolls at the same speed as the ground speed. Cylinder or rotor speed can be adjusted to minimize threshing loss and kernel damage. Adjust combine settings and fan speeds whenever harvesting stressed plants with lighter kernel weights. Understanding your corn’s stalk integrity across fields is crucial helps determine a profitable plan by minimizing harvest losses.

Contact your Golden Harvest Seed Advisor with questions or for additional agronomic insights.

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