* Open Yield Monitor Data Services folder in Store to access more background information *
Yield Map Cleaning and Management - Corn and Soybean Example Slideshow
Sudduth and Drummond (2007) report research that shows 10 to 50 percent of yield points need to be removed and that the erroneous data can strongly effect the resulting yield distribution; they state “if the errors are not addressed, the user of the yield map may reach erroneous conclusions, calling into question the credibility and validity of the results”.
Images transition every 4 seconds (or click arrows or dots); description appears below graphic
Points are classified with natural breaks (lowest to highest is red, orange, yellow, green, and dark green).
The map is initially assessed for the accuracy of grain flow delay (a correction is not necessary for the yield maps shown above); a correction to the yield map may or may not be necessary. Duplicate (co-located) points can occur in yield monitor data; if there are duplicate points after manual removal of yield points, they are removed at that point (prior to outlier removal) as is the case with the soybean yield map. The map is assessed after outlier removal to determine if more manual editing is needed; if it is necessary (as is the case with both examples above), more editing is done at that point.
Points in the clean, smoothed map are calibrated to the yield range and average amount of the last map (step) prior to smoothing (which is outlier removal or [usually] more manual editing); or calibration of a range and average yield amount can be to your specification.
When one map is cleaned, all subsequent maps can have points at the same location (as is shown in the slideshow) which will help with organization and to determine yield patterns (and statistics) at the same location over time. To do this, the nearest yield points from a clean yield map with one-meter spacing is joined to the points; the average distance a joined point will be is about one foot. Points at the field boundary that essentially encircle evenly spaced yield points can also be included. This is described and shown in the Yield map management and statistical mapping page.
Reference
Sudduth, K.A., and S.T. Drummond. 2007. Yield Editor: Software for Removing Errors from Crop Yield Maps. Agronomy Journal99: pp. 1471–1482 (pdf) (document opens in new window)