Common Nutrient Deficiency Symptoms
Soybeans
 
 
Nitrogen Deficiencies:
Nitrogen Deficiency Nitrogen: 
Symptom: Yellow coloration (lower leaves are pale) 
 
Causes: 
  1. uninoculated soybean seeds
  2. ineffective N fixation in cooler/wetter soils
Remedies: (Corresponds to numbers above) 
  1. inoculate seeds with fresh inoculant
  2. install drainage tiles in heavier soils
 
 
 
Potassium Deficiencies:
Potassium Deficiency Potassium Deficiency
Symptom: 
Yellow and brown coloration of leaf margins 
  • occurs first on lower leaves
  • may progress to upper leaves
Causes: 
  1. under-application of K fertilizer needs
  2. cooler/wetter weather (environmental)
  3. Plant K inefficient hybrids
Remedies: (Corresponds to numbers above) 
  1. apply appropriate fertilizer K rate
  2. avoid earliest planting dates (warmer weather can correct symptoms)
  3. plant K efficient hybrids
 
 
Iron Deficiencies: 
 Iron Deficiency Iron Deficiency
Symptom: 
Yellow coloration between leaf veins / total yellow leaf 
  • occurs in upper leaves
Causes: 
  1. soil has high pH (>7.5) or high salt
  2. planted Fe inefficient varieties
Remedies: (Corresponds to numbers above) 
  1. install drainage tiles in heavier soils - Application of Fe-Chelates is too costly
  2. plant high pH tolerant varieties
 
Other nutrient deficiency symptoms are not very obvious.  Testing the soil for nutrient levels is the only sound approach to determine whether fertilizer applications are necessary.
We appreciate the use of those photographs which were contributed by the Potash and Phosphate Institute and Farmland Industries.

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