Estimating Harvest Losses in Cereals – Don’t Just Rely on the Grain Loss Monitor!

UPDATED FROM ARTICLE POSTED ON AUGUST 12, 2015

Winter wheat and fall rye harvest is underway in Manitoba. Since final yields aren’t determined until the crop is in the bin, attention now has to be focused on the harvest operation. Grain loss at harvesting time is a direct loss of income. The more grain saved, the greater the returns. The following information comes from 2 articles: ‘Grain Harvest Losses’ by V. Hofman with edits by Dr. J Wiersma & T. Allrich (University of Minnesota) and ‘Estimating Harvest Loss’ by G. Carlson & D. Clay (South Dakota State University).

Grain harvest losses result from shattering of the standing grain, shattering during windrowing (swathing) or direct combining, picking up the swath with the combine, and threshing, separating and cleaning within the combine. Estimates of acceptable losses for small grains such as wheat, barley and oats are placed at 3% of total yield (total yield equals harvested yield plus harvest losses).

It is usually very difficult to reduce total losses below 1 to 2% so the operator must decide on the value of the crop, the cost of combining and the time available for combining or climate conditions. Some harvest loss is unavoidable in order to get harvesting done in the time available with an end goal of cleaned harvested grain.

Estimating Harvest Losses.  Advancements in engineering have greatly improved harvest operations. Combines have various types of monitoring equipment available, including grain loss monitors, to help alert the operator to any potential problems.  A grain loss monitor is a good guide in selecting travel speed for varying conditions such as size of windrow and moisture conditions. A grain loss monitor must be calibrated to provide an acceptable grain loss reading. If the combine is used on different crops, the monitors are not only useful in limiting maximum speeds and losses, but can be used to properly feed the combine for optimum capacity.

However, a grain loss monitor is not a substitute for careful machine adjustments and good old fashioned monitoring, i.e. getting out of the combine to estimate losses. Or even better, when your local retail agronomist comes out with cold beverages, put him/her to work to estimate harvest losses.

A simple and rough estimate of grain loss requires the use of a one-foot square frame. A rough estimate of how much grain is left behind in a harvested field can be done with a few simple steps:

  1. Pick a typical area of the field after the combine has passed.
  2. Place a 1 ft by 1 ft (inside dimension) box on the ground and count the kernels found within the box. To improve accuracy, three counts (one behind the left side of the header, one behind the centre of the combine, and one behind the right side of the combine) are better.
  3. A one (1) bushel per acre loss equates to 20 wheat kernels/ft2, 14 barley kernels/ft2 and 10 oat kernels/ft2. Keep in mind that this is a ‘fudge factor’ but for the purpose of rough field estimation is an adequate estimate. There are more accurate ways to estimate harvest losses which take into consideration the width of windrower cut and combine cylinder.

If losses are on the high end, some investigation is warranted to try and identify the source of loss.  Is the crop shattering prior to the arrival of the combine (to check for losses that occurred prior to the arrival of the combine, i.e. shattering, use the method above in the unharvested areas of the field)? Are there header losses? Or are the losses due to less than perfect threshing/separation of grain within the combine?  Finding the answer may help to adjust the harvest operation and maximize the amount of grain going into the bin!

Good luck with #Harvest16!

Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

Manitoba Agriculture website: www.manitoba.ca/agriculture
Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture
Respond
Have a follow-up question?

Don’t Rely Solely on Your Grain Loss Monitor – Estimating Harvest Losses in Cereals

It is harvest time in Manitoba. Since final yields aren’t determined until the crop is in the bin, attention now has to be focused on the harvest operation. Grain loss at harvesting time is a direct loss of income. The more grain saved, the greater the returns. The following information comes from 2 articles: ‘Grain Harvest Losses’ by V. Hofman with edits by Dr. J Wiersma & T. Allrich (University of Minnesota) and ‘Estimating Harvest Loss’ by G. Carlson & D. Clay (South Dakota State University).

Grain harvest losses result from shattering of the standing grain, shattering during windrowing (swathing) or direct combining, picking up the swath with the combine, and threshing, separating and cleaning within the combine. Estimates of acceptable losses for small grains such as wheat, barley and oats are placed at 3% of total yield (total yield equals harvested yield plus harvest losses).

It is usually very difficult to reduce total losses below 1 to 2% so the operator must decide on the value of the crop, the cost of combining and the time available for combining or climate conditions. Some harvest loss is unavoidable in order to get harvesting done in the time available with an end goal of cleaned harvested grain.

Estimating Harvest Losses.  Advancements in engineering have greatly improved harvest operations. Combines have various types of monitoring equipment available, including grain loss monitors, to help alert the operator to any potential problems.  A grain loss monitor is a good guide in selecting travel speed for varying conditions such as size of windrow and moisture conditions. A grain loss monitor must be calibrated to provide an acceptable grain loss reading. If the combine is used on different crops, the monitors are not only useful in limiting maximum speeds and losses, but can be used to properly feed the combine for optimum capacity.

However, a grain loss monitor is not a substitute for careful machine adjustments and good old fashioned monitoring, i.e. getting out of the combine to estimate losses. Or even better, when your local retail agronomist comes out with cold beverages, put him/her to work to estimate harvest losses.

A simple and rough estimate of grain loss requires the use of a one-foot square frame. A rough estimate of how much grain is left behind in a harvested field can be done with a few simple steps:

  1. Pick a typical area of the field after the combine has passed.
  2. Place a 1 ft by 1 ft (inside dimension) box on the ground and count the kernels found within the box. To improve accuracy, three counts (one behind the left side of the header, one behind the centre of the combine, and one behind the right side of the combine) are better.
  3. A one (1) bushel per acre loss equates to 20 wheat kernels/ft2, 14 barley kernels/ft2 and 10 oat kernels/ft2. Keep in mind that this is a ‘fudge factor’ but for the purpose of rough field estimation is an adequate estimate. There are more accurate ways to estimate harvest losses which take into consideration the width of windrower cut and combine cylinder.

If losses are on the high end, some investigation is warranted to try and identify the source of loss.  Is the crop shattering prior to the arrival of the combine (do the above steps before harvest to determine this)? Are there header losses? Or are the losses due to less than perfect threshing/separation of grain within the combine?  Finding the answer may help to adjust the harvest operation and maximize the amount of grain going into the bin!

Good luck with Harvest 2015.

Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

 

Respond
Have a follow-up question?
,

Over Wintering Corn? Points to Consider

There remains grain corn to be harvested in some parts of Manitoba, due in some cases to high kernel moisture contents and immature crop.  Corn in the field may dry about 0.3 to 0.5 percentage points per day during October; however, that decreases to 0.15 per day or less during November.  The amount of drying in the field will depend on factors such as corn maturity, hybrid, moisture content, air temperature, relative humidity, solar radiation and wind speed.

Table 1: “Estimated” Corn Field Drying

Picture3Source:  Dr. Kenneth Hellevang, NDSU Extension Service.

 

However, what is interesting is regardless of kernel moisture content in November, if left standing the crop can dry down moisture contents below 20%.  The following figure from MASC illustrates this point.

Figure 1:  Grain Corn Moisture Content Change (1992)

Picture2

Source: MASC

 

Yield Loss.  If the stalks stay standing and there isn’t much ear drop, snow cover or wildlife damage, the crop can get through the winter without much yield loss. However, notice the number of disclaimers in that sentence. Ear drop will vary by hybrid and environmental conditions as well as the amount of grain on the ear (smaller ears should stay attached better than larger ears).  Stalk strength may have also been compromised this year due that early September frost event; although the cool temperatures did not kill the plant outright and only leaf material, the plant would have ‘scavenged’ resources from within itself, i.e. the stalk, to help with grain fill.  This would lead to compromised stalk strength.

If winter conditions are cool without snow then corn will continue to dry and can be harvested throughout the winter.

If you do find yourself in the position of wanting to over winter your corn, please touch base with your local MASC agent.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

Respond
Have a follow-up question?

Managing Fusarium Head Blight At Harvest

Winter wheat harvest 2014 will start shortly in Manitoba.  Field surveys being conducted by MAFRD staff are indicating higher than normal levels of fusarium head blight (FHB) in many winter wheat fields.

Unfortunately at this late stage of the growing season where harvest is right around the corner, there are no easy answers in managing FHB that is present. However, before harvest (and before a preharvest treatment is applied if one is planned), farmers and agronomists should head out to the fields for some final scouting to determine what, if any, harvest and storage strategies can be used to minimize the impact of fusarium damaged kernels. Careful harvesting, drying and storage strategies are the farmer’s best way to try and maximize grain quality and marketability.

The key at harvest is to try and prevent infected kernels from going into storage. Here are a few suggestions:

  • Thoroughly scout each field noting if there are any differences in infection levels between fields or if there are patterns within fields that are more affected by FHB, such as low areas or fungicide application misses.
  • Use higher fan speeds to try and blow infected kernels out the back. Research at Ridgetown found there was a tenfold decrease in Fusarium-damaged kernels in the grain sample when fan speeds were operated to deliver maximum air blast. However, the downside to this strategy is higher fan speeds can result in healthy kernels going out the back as well. And infected kernels blown out the back can provide a source of inoculum in future years.
  • Reduce combine travel speed as the slower speed allows for increased separation of the grain by allowing the increased air blast time to separate the good kernels from the infected kernels.
  • After harvest, gravity table grain separation may be effective in removing light-weight, damaged kernels. The increased marketability of the cleaned grain may pay for the cost of the clean-out process.

For additional information on harvest, drying and storage, as well as seed and feed considerations, visit MAFRD’s website at http://www.gov.mb.ca/agriculture/crops/plant-diseases/managing-fusarium-head-blight-harvest.html

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist

Respond
Have a follow-up question?

When is the Best Stage to Roll Soybeans After They Have Emerged?

Submitted by Dennis Lange, MAFRD Farm Production Advisor (Altona).  Updated from Manitoba Cooperator article by Allan Dawson, published on June 27, 2013 “Trifoliate stage best for rolling soybeans after emergence”

Don’t roll soybeans until they reach the first trifoliate stage, or you risk breaking too many young plants.

  • You don’t want any beans at the hook stage
  • Only roll if you have some stones or dirt that will cause you some harvest issues
  • Wait until later in the day when it’s warmer and plants are more plastic and should have less breakage (check to see if plants are breaking) 

Why Roll Your Soybean Field?

Rolling pushes down stones and levels the field allowing the combine cutter bar to be set lower and pick-up low-handing pods.  It can make soybean harvesting faster, more efficient and will reduce the risk of stones damaging the combine.

Soybean plant at firth trifoliate. Picture by Dennis Lange, MAFRD

Soybean plant at first trifoliate. photo: Dennis Lange, MAFRD

These emerging soybeans are at the hook stage. Rolling plants at this stage will cause a lot of plant damage. photo: Dennis Lange, MAFRD

 

This soybean plant is at the unifoliate stage with two true leaves and the cotyledons below. photo: Dennis Lange, MAFRD

 

Respond
Have a follow-up question?