Know your deficiency and how to treat it
Nutrient deficiencies not only rob yield potential but it signifies a possible problem with overall soil health. Deficiencies can be avoided through pinpointing the problem, soil testing and proper application of necessary nutrients.
Below are the five most common nutrient deficiency symptoms in corn and how to correct the problem:
Nitrogen (N) deficient corn
Corn suffering from nitrogen deficiency generally has a V-shaped yellow coloration, which progresses from the leaf end to the leaf collar and moves from the lower to upper leaves.
| Common Causes: | Treatment: |
| Under-application of N fertilizer | Appropriate fertilizer N application |
| Underestimation of N release in manure | Analyze manure for N content |
| Leaching of nitrate due to rainfall or irrigation | Apply level appropriate for soil |
| Loss of N as a gas after water ponding or in compacted sites | Install drainage tiles in heavier soils and/or minimize field compaction |
| Onset of dryer weather | Irrigate if possible |
Phosphorous (P) deficient corn
Phosphorous deficient corn is recognizable by the purple coloration on the lower leaves.
| Common Causes: | Treatment: |
| Under-application of P fertilizer needs | Apply fertilizer P as a ‘starter’ application |
| Cooler/wetter weather | Avoid earliest planting dates (warmer weather can correct symptoms) |
| Planted P inefficient hybrids or Inherited tendency of some hybrids | Plant P efficient hybrids |
Potassium (K) deficient corn
Yellow and brown coloration of leaf margins, which occur on lower leaves first and progress to upper leaves are symptoms of potassium deficient corn.
| Common Causes: | Treatment: |
| Under-application of K fertilizer | Apply appropriate fertilizer K rate |
| Cooler/wetter weather | Avoid earliest planting dates (warmer weather can correct symptoms) |
| Planted K inefficient hybrids | Plant K efficient hybrids |
Sulfur (S) deficient corn
Sulfur deficiency is recognizable by the yellow, striped pattern on corn leaves or interveinal chlorosis pattern. This is generally found in younger leaves.
| Common Causes: | Treatment: |
| Under-application of S fertilizer | Apply appropriate fertilizer S |
Reduced mineralization due to: 1. Eroded knolls and hillsides, which have lower organic matter than rest of the field |
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| 2. Mineralization of organic-S to sulfate-S in fields under no-till cultivation is reduced compared to cultivated fields | 2. Apply fertilizer in sulfate form as ammonium sulfate or ammonium thiosulfate. Elemental S may take several years to increase sulfate-S levels. |
Zinc (Zn) deficient corn
Zinc deficient corn will have broad-band yellow coloration and generally occurs in upper and mid-level leaves, which may progress outward.
| Common Causes: | Treatment: |
| Under-application of Zn fertilizer | Apply appropriate fertilizer Zn needs as starter fertilizer (Sn-Chelates are not recommended due to high cost) |
Soil has pH >7.5 | Avoid planting in very high pH soil |
Soil testing and creating an effective nutrient plan will aide in avoiding these yield-robbing problems.
Use these resources to help you boost yields and create a winning nutrient management plan:
- Give Soil A Physical
- A Deeper Understanding: New Soil Testing Could Improve Soil Health
- Healthy Soi? Not Before You Address These Three Things
- Managing Nitrogen in a Complex Partnership
- Step-by-Step Sulfur
- Purdue University Study: Sulfur Deficiency in Corn
Source: South Dakota State University
