Winter wheat harvest season is upon us, and harvest efficiency plays a critical role in protecting yield and profitability. Reducing harvest losses from 5% to 3% in a field averaging 75 bushels/acre recovers an additional 1.5 bushels/acre. If growers receive $5/bushel, that equates to an extra $7.50 per acre income. While that might not sound like much, they add up on the field level and every dollar counts when farm economics are tight.
Besides potential loss of income, wheat kernels lost at harvest will become volunteer wheat which may act as a weed in some cases. This may be problematic for those considering late summer seeded alfalfa or certain cover crops. Planting legume cover crops after wheat harvest is a great opportunity to utilize the remainder of the growing season to build nitrogen for next year’s crop, but competition with volunteer wheat can reduce establishment and create inconsistencies throughout the field.
Combine operators should take time to determine how much harvest loss is happening in the field and make adjustments to mitigate the problem.
How to determine harvest loss: Find them, fix them
Count the number of wheat kernels within one square foot on the ground in the discharge area behind the combine. It is best to repeat this process in several locations in this area and determine an average. There is approximately one bushel per acre loss for every 20-22 kernels on the ground depending on the size of the kernels. Do not count shriveled, light, or aborted kernels.
However, not all kernels on the ground behind the combine may be the result of machine settings. Pre-harvest shatter losses and broken stems can be a factor. Check the standing crop ahead of the combine and evaluate the number of kernels within one square foot. This number should be subtracted from the number of kernels found per square foot in the discharge area since pre-harvest losses cannot be reduced with machine adjustment.
This process can also be used to help diagnose where harvest losses are occurring. Counting the number of kernels in one square foot alongside the combine (behind the header but ahead of the discharge area) and subtracting pre-harvest loss numbers indicates how much harvest loss can be attributed to the head of the combine. Kernels that are not lost pre-harvest or at the header can be the result of threshing, separating, and cleaning.
If total harvest losses exceed one bushel per acre, there is room for improvement and adjustments should be made.
Dial in the settings on your Combine to save more grain
For losses occurring at the head of the combine, determine if reel speed is too fast, or if the knives are in poor condition. Proper reel speed is important for thorough grain harvest as reel speed should match the ground speed. Dull knives tend to shake the plants more than sharp knives, leading to increased shatter loss. If whole wheat heads are observed on the ground, the reel height and cutterbar may need to be adjusted or the reel speed is too low.
Once the header adjustments have been made, there may still need to be corrections made in threshing, separating, and cleaning. Unthreshed kernels are a sign that thresher speed should be increased or concave clearance should be decreased. Alternatively, damaged kernels in the tank indicate that thresher speed should be decreased, or concave clearance should be increased. Fan speed should be high enough to lift chaff and straw out, but not so high that it blows grain out of the combine. Utilize your specific combine’s operating manual as a resource for more settings to consider.
The success of these mechanical settings is highly dependent on having a consistent flow of material, or feed rate, into the combine. This is influenced by many factors including ground speed, crop yield, and moisture. Harvesting wheat below 14% will likely increase shatter and head loss while harvesting at a higher moisture, such as 18% will require more aggressive threshing to separate seed from head.
Conditions may change from field to field, or even within a field due to varying soil types, field slopes, and weather changes throughout the day. Recognizing these changes and fine-tuning adjustments on the go is important to maximizing the efficiency of the combine and minimizing loss.
Conclusion
Harvest season can feel like a rush, but investing time in evaluating harvest loss has several benefits for producers. Minimizing wheat harvest losses requires attention to detail, consistent evaluation, and timely adjustments throughout the harvest process. Staying attentive to changing field conditions and maintaining optimal combine settings ultimately helps ensure that more grain makes it into the tank and fewer resources are left behind.
Jordyn Sattler is the Regional Crops and Soils Educator for Grant, Green, Iowa, and Lafayette Counties via UW-Madison Division of Extension
This article originally appeared on Wisconsin State Farmer: Keep more grain in the bin by paying attention to detail during harvest
Reporting by Jordyn Sattler, Wisconsin State Farmer / Wisconsin State Farmer
USA TODAY Network via Reuters Connect
By Jordyn Sattler, Wisconsin State Farmer | USA TODAY Network
