Harvest is underway – update and calibrate yield monitors

Tony Nye - OSU Extension

Harvest is underway in Southwest Ohio, but you have to look around to find the activity. I know there has been some corn harvested in Clinton County, but no yield reports as of yet.

It won’t be long before many producers will be hard at it, gathering the harvest. Remember with grain harvest comes lots of big equipment moving from field to field, farm to farm and at a much slower speed than most of you like driving. My recommendation to all of you that have to pass me each day at speeds greater than 60 mph, be alert, give yourself extra time and just simply slow down!

Weather for harvest is always a concern. This year will be no different. According to weather forecasts, as we move into harvest season, It does look like there could be some delays in harvest this fall especially west of Ohio. However, it does not look real significant. Historic autumns coming out of big El Nino events are usually warmer than normal, a slightly later freeze and rainfall that goes from drier than normal to normal or slightly wetter than normal by the end of fall.

Weather experts suggest that it looks like lots of fall swings are in store. However, for the remainder of September, even though we will have bursts of cooler temperatures we still expect temperatures to average 1-3°F above normal.

Rainfall is more complicated as there are indications of a slightly wetter period coming for the second half of the month around a high pressure system in the Southeast U.S. Therefore, we expect rainfall to average from 0.50 inches below normal to 1.00 inches above normal for the rest of the month of September.

The experts are looking at October to return to drier than normal for the first half of the month with temperatures possibly cooler a few degrees below normal.

Again the trend into November is still preferred warmer than normal with precipitation becoming variable.

Finally, based on the ending of El Nino with a chance of La Nina by winter, indications are the first freeze would arrive from normal to a week late this year. Typically first freezes are in the Oct. 10-20 range.

As the use of precision agriculture continues to increase across the US, it is more and more important to ensure that all equipment is prepped, calibrated, and ready for a successful harvest.

One of the more common uses of precision agriculture comes in the form of yield mapping. Yield maps not only help growers understand end-of-year performance within fields, but also can be used to characterize in-field variation. Information about this variation is often used by service providers to deliver prescriptions, recommendations, or other information back to the farmer.

Because yield maps continue to be an important data layer to learn from and help drive changes or decisions at a field level, proper management of the yield monitor in 2016 is key to generate accurate and reliable yield data. Grain moisture and test weight, along with grain flow through the combine, will vary within passes and across the field. Therefore, the flow and moisture sensors on combines must be calibrated to these expected conditions in order to log accurate data.

Ohio State University Agriculture Engineer and Precision Ag Specialists recommend the following best practice guidelines for essential pre-harvest and harvest yield monitor tips:

• Be sure to update firmware and/or software for the yield monitoring systems.

Most yield monitors use a mass flow sensor at the top of the clean grain elevator. Due to the grain impact, the plate will wear to the point of developing a hole if it isn’t replaced soon enough. The wear that occurs changes the reading from the mass flow sensor. Be sure to replace the plate if wear is evident. Don’t neglect to recalibrate after replacing yield monitor components.

A more simple explanation is that a worn impact plate can result in an incorrect yield reading on your display. It is important to not overlook the yield mapping system as a worn component will throw off yield readings.

• Update and/or configure DGPS. Software related to auto-steer, yield monitors and other GPS-based systems requires separate attention. Licenses must be renewed. Calibrations and parameters must be updated or confirmed — especially if the display screen in the combine cab was used for planting or spraying earlier in the year

Check auto-steer operations and that previously used AB/guidance lines are available within the display. Remember, you may have to adjust sensitivity settings.

• It is also important to calibrate yield monitors for every crop, each season to ensure that all data being collected is as accurate as possible. The yield monitor needs to “be taught” how to convert the readings from the mass flow sensor into yield; therefore, it is necessary to show the yield monitor the range of yield conditions it will encounter throughout the season.

It is wise to periodically check the calibration throughout the season to be sure the data being collected is still accurate.

Remember to recalibrate if harvest conditions change.

The use of grain carts to calibrate yield monitors can be acceptable as long as it weighs accurately compared to certified scales.

• Bring along your field notes so you can review them during harvest as crop conditions vary or issues are observed.

While harvest is a busy time, taking notes and images during harvest (especially if conducting on-farm research) can be valuable data when finally sitting down for post-harvest analysis and summary. We all forget, so notes and images can help document important information!

Tony Nye is the state coordinator for the Ohio State University Extension Small Farm Program and has been an OSU Extension Educator for agriculture and natural resources for 28 years, currently serving Clinton County and the Miami Valley EERA.


Tony Nye

OSU Extension