The Difference Between Nitrogen and Potassium Deficiencies

Here’s the key way you can know the difference in the field.

It could be easy to confuse a potassium or nitrogen deficiency in the field. But Farm Journal Field Agronomist Ken Ferrie says you only need to understand how the plant shows its deficiency in the nutrients. He explains as a response in the Ask an Agronomist segment of Episode 2 of Corn College TV.

“Both nutrients are mobile and move from the oldest to the newest part of the plant,” Ferrie says. “But it’ll look different on the corn’s leaf.”

Nitrogen deficiency starts at the tip of the leaf and comes down through the mid-rib so they will be a V-pattern through the mid-rib.

However, potassium looks somewhat the same but different. Its deficiency starts at tip but then goes down through the outside of the leaf.

Ferrie warns that if you apply more nitrogen when there’s a potassium deficiency, that can make that nutrient deficiency worse.

You can learn more in Episode 2 of Corn College TV.

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