Corn Yield as Influenced by In-season Application of Nitrogen with Limited Irrigation1
- C. K. Anderson,
- L. R. Stone and
- L. S. Murphy2
With limited irrigation of corn (Zea mays L.) on medium or fine textured soils, the initial application of water (and thus of N being water applied) would perhaps be no earlier than when corn is at the 12 or 14-leaf growth stage. This experiment was established to evaluate the effects of delaying N application until the 14-leaf or silk emergence growth stages on yield of corn on a medium-textured soil.
The study soil is a coarse-silty, mixed, mesic, Fluventic Hapludoll near Manhattan, Kansas. Ten treatments (combinations of N application time and rate, each replicated three times in a completely randomized design) were applied in each of 3 years. Nitrogen was broadcast applied (preplant) and applied with irrigation water (at the 14-leaf stage and/or at early silking).
Grain N content increased as N fertilizer rates increased and as N application time was delayed. No corn grain or dry matter yield advantage was found for split applications or for in-season applications of N over preplant application. Corn receiving 101 kg N/ha at the 14-leaf stage produced 94% of the grain obtained when 101 kg N/ha was applied preplant. Corn receiving 101 kg N/ha at silk emergence produced 71% of the grain obtained when the same N rate was applied preplant. Our findings indicate that with limited irrigation of corn on medium to fine-textured soils, all N should be applied preplant rather than in-season with irrigation.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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