Pinpoint Management of N, P, K in Your Corn Fields

04:15AM Jan 01, 2011
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When trying to decide if you have nutrient deficiencies of N, P, or K, your first step could be to look up your most recent soil test. But understanding nutrient deficiencies with the big three could involve additional steps says Farm Journal Associate Field Agronomist Missy Bauer as she explains in episode 10 in Corn College TV.

“You may have to pull new soil tests,” she says. “Or you may need to pull tissue samples for analysis. The way you pull those samples depends on time of year. It could be an ear leaf sample, whole plants, or the  upper fully developed leaf.”

In identifying nutrient deficiency in the field, Bauer breaks down these visual signals:

episode10 headtothefieldNitrogen deficiency–can be identified by the leaves, makes a v-shaped pattern of yellowing coming toward the plant. It can be hard to judge if the whole field shows the same symptoms. Severe nitrogen deficiency will show tip pull back and kernel abortion.

Potassium deficiency–can see it on the edges of the leaf. It affects stalk quality. You’ll see the deterioration of the inside of the stalk, which weakens the stalk.

Phosphorus defiency– look early in the season for darkening of the plant and purple color. If severe enough, you can see spiraling of the kernel rows. But early-season deficiency will lead to fewer number of rows around the ear.

Learn more about nutrient deficiencies in episode 10 of Corn College TV.