Fall or early spring applications of anhydrous ammonia commonly are assumed to prevent deficiencies of nitrogen (N) in young corn plants. Corn plants in many fields this year indicate that this assumption should be questioned.
Corn plants often show exactly when their roots first reach bands created by injection of anhydrous ammonia. This time is most detectable when the bands are not parallel to rows of plants. Plants directly over the bands benefit first. These plants become darker green and grow more rapidly than plants not directly over the bands. For a few days, streaks of green plants reveal the exact locations of the bands. These streaks tend to disappear as root systems develop enough that all plants reach the fertilizer.
Iowa State University
Blackmer, Alfred M., "Corn roots are just reaching anhydrous bands" (2001). Integrated Crop Management News. 1927.
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