Late summer stress is beginning to show in Iowa’s soybean crop.  As you travel around Iowa, you will begin to see yellowing in many soybean fields that should be dark green this time of the year. 

Taking a late season tissue sample can be a valuable piece of in­formation in determining what is causing the lime green to yellow appearance in certain areas of the field.

Most commonly the cause of “yellowing” is nutrient deficiency, but not...