Could the N in manure be lower quality?

Published on: 16:36PM Feb 23, 2010

I’m a dairy farmer who uses cattle manure as the nitrogen source for my corn crop. For corn on corn, I knife the manure in the field in the fall and then chisel the cornstalks. In the spring, I make a pass to level the field and then plant. Shortly after the corn comes up, it looks yellow and sickly. Is the nitrogen in my manure any good, and should I really count it in my program?

—Southern Wisconsin

The nitrogen in your manure is as good as any other source of nitrogen you can buy. The sickly yellow corn you’re seeing in the field is due to the timing and placement of your nitrogen application.

Neither manure nor banded nitrogen do a good job of paying the carbon penalty in the spring because the manure has to decompose to become available to the corn. You’re applying the nitrogen in a concentrated form, which doesn’t help the breakdown of residue on the surface, and it’s too far away from the small plant.

Once your corn plant gets enough depth of root, it should reach the nitrogen and pick up its color to turn green. But corn can go through a tough period before its roots reach the source of nitrogen. Think about backing up your manure rate. And save some of your nitrogen to apply in a spring surface application or put some of the nitrogen allotment on with your corn planter. Applying nitrogen with the planter will help the corn early on until it can grow to reach the banded manure.


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