In an earlier post I talked about normalizing as a different way of looking at yield data. Normalized data gives you the advantage of being able to look at field’s performance across multiple years and multiple crops to help identify management zones within a field. Last time we looked at only one year of data with a tradition yield map compared to a normalized map. By normalizing we had a better picture of where yield differences occurred for a single year. This time we will look at the same field over a two year period. In 2009 the field was planted with soybeans behind wheat and followed in 2010 with corn that we looked at earlier.
Now let’s look at the same field in 2009 planted to soybeans. Just as a note these were late planted wheat beans. As most of you remember 2009 was extremely dry up until harvest. This crop both benefited and was hurt by the excessive rain in August till harvest in November. This is another good example of why I like to normalize a field and get away from bushels.
As we study these maps we see the same yield patterns begin to develop across the field in almost the same locations as in the 2010 corn. You will notice that on the northern edges of the field we had no harvest information. This is because of the heavy rain, this portions of the field was lost to flooding. Again we see the south end of the field out yielded the north end of the field, this is clearer in the normalized map than the traditional yield map. Now let’s create a normalized map for multiple years across multiple crops to see if yield patterns are consistent from year to year with different crops.
As you study this map we see that the south end of the field still continues to out yield the north end of the field year after year regardless of the crop. The soil in the south end is a sandy loam and changes to heavy clay in the middle of the field north. There are also problems with getting water to the north end of this field and the dark red area to the north is where a pipeline crossed a few years ago resulting in a change in soil structure.
Knowledge of the field, yield maps and normalized date are tools to identify differences in a field so you can make better management decisions.