The recent heavy rains have raised questions about nitrogen (N) losses. In wet field areas it is common to find off-color corn, but that does not necessarily equate to N shortage. So be careful as you initially are seeing plant response to wet conditions (slowed root activity and growth). The amount of N taken up by corn to the V6 stage is small (about 20 pounds N per acre, so pale-yellow color is now due to wet conditions).
Iowa State University
Sawyer, John E., "Nitrogen losses after the heavy rains" (2004). Integrated Crop Management News. 1551.
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