I know that most Ohio growers are already in the field busy with harvest. However, I thought it would be appropriate to remind growers of the importance of monitoring harvest losses throughout the harvest season, not just the first few days. We know that losing some grain during harvest is inevitable but measuring that loss behind the combine can pay big dividends to those who make adjustments during harvest. The combine owner’s manual is the best place to start in making sure that you don’t leave grain in the field above the normal and acceptable loss.
Every bushel of soybeans or corn left behind by the combine represents a loss in profits. While harvest losses cannot be completely eliminated, timely combine adjustments can reduce losses to 1 or 2 bushels per acre.
Measuring soybean harvest loss
To determine soybean harvest losses, count the number of beans on the ground in a 10 square foot area. Divide the number of beans in the 10 square foot area by 10 to determine the number of beans lost per square foot. Four beans per square foot equals 1 bushel per acre loss. Dividing the number of beans per square foot by 4 will give the loss in bushels per acre. Make loss determinations at several locations and calculate an average.
Reducing soybean harvest loss
Soybean combine losses can be as much as 15%. Careful maintenance and operation can help keep soybean harvest losses to 3%, which would be 1.35 bushels in a 45-bushel crop (or 5.4 beans per square foot). Most of soybean harvesting losses occur at the gathering unit of the combine between the header and standing beans. Loss at the gathering unit is often from shattering.
Shattering loss can be reduced by harvesting soybeans as quickly as possible when soybean moisture reaches 15% according to University Specialists. Ground speed should be reduced to 3 miles per hour or less, and reels should operate about 25% faster than ground speed. The best guide for correct combine settings and adjustments is your operator’s manual.
Measuring corn harvest loss
Determine total ear loss by counting the number of full-size ears, or the equivalent, in a 1/100-acre area. For 30-inch row corn, that is 17 feet 5 inches. For 20 inch row corn that is 26 feet 2 inches. Each full-size ear represents about 1 bushel per acre loss.
To measure kernel loss, count the loose kernels on the ground and those still attached to threshed cobs in a 10 square foot area for each row behind the combine. The area should have width equal to the planted row width. Two kernels per square foot equals a 1 bushel per acre loss.
Reducing corn harvest loss
Proper combine setting will allow you to maximize income by reducing harvest loss and reduce volunteer corn issues next season. Mechanical losses may be due to ear drop, stalk lodging, and kernel shattering.
These losses are expected, but keeping them to a minimum of 1% for ear loss, 0.3% threshing loss, and 0.5% loose kernel loss should be the goal according to University specialists. Altogether, a 1.8% mechanical loss from a 150-bushel corn yield would be 2.7 bushels per acre or an average of 5.4 kernels per square foot.
Ear loss can be minimized by setting snapping rolls to fit stalk width, and running snapping rolls at the same speed as ground speed. For most of Ohio there should be a large difference between 2013 stalk diameters and 2012. Cylinder or rotor speed can be adjusted to minimize threshing losses and kernel damage. Loose kernel losses can be affected by fan and shoe settings, and combines should be adjusted where stressed plants produced lighter kernels. Follow manufacturer’s settings to minimize losses.
As always, Please keep safety at the top of mind as you progress through the harvest season. We appreciate your business!