Soybeans were scouted at the early R5 growth stage and yellowing of leaf margins were observed in areas across the field.
This issue was confirmed by an NC State Extension Specialist as a Potassium (K) Deficiency. Stunted plants, slow growth, and marginal chlorosis can be associated with a potassium deficiency. Soybeans require a high amount of potassium, and the uptake of this nutrient is driven by diffusion. So, in an environment of droughty conditions a K deficiency may be seen. The best way to ensure and maintain the correct nutritional needs for a field is to conduct soil sampling every 1 to 2 years.