GPS-based yield data has proven to be an extremely valuable management tool on many farms. However, improperly calibrated yield monitors can essentially generate difficult to interpret or useless data.

Economic risk in agriculture has increased dramatically. Considering the amount of economic risk involved in each decision, taking the time and patience to properly calibrate a yield monitor is essential if the yield data will be used to make future agronomic decisions for your farming operation.

Most yield monitors operate on the same basic principles. Yield monitor manufacturers strive to build accuracy into their units; however, each machine has its sources of errors. Proper calibration requires harvesting three to five separate calibration loads. Each load should represent different flow rates. This can be easily accomplished by harvesting at different speeds (i.e. 3 mph, 3.5 mph, 4 mph, 4.5 mph, 5 mph, etc.) The different flow rates represent different yield levels to the yield monitor. Additionally most manufacturers recommend that the calibration load weigh between 3,000 and 6,000 pounds, approximately 50-100 bu. Each load should be individually weighed in a weigh wagon or other accurate scales. If one load appears to be uncharacteristically high or low, redo that load before completing the calibration.

Check the accuracy of your yield monitor throughout the harvest season. To ensure consistent data, additional calibrations may be necessary. Multiple calibrations are essential in higher moisture grain. For example corn at 25% moisture moves through a combine much differently than corn at 17% moisture.

Other important tasks:

  • Calibrate for each grain type.
  • Calibrate grain moisture sensor
  • Calibrate temperature sensor