Sprinkler-Applied and Side-Dressed Nitrogen for Irrigated Corn Grown on Sand
1984
Gascho, G. J. | Hook, J. E. | Mitchell, G. A.
Maintaining efficient N nutrition for irrigated corn (Zen mays L.) grown on deep sands is difficult due to low N supplying capabilities and leaching losses of applied N. Scheduled applications of N by the use of center-pivot irrigation equipped with modern solution injection equipment should reduce leaching and increase N-use efficiency. The objective of this study was to compare the efficiency of scheduled applications of N through sprinkler irrigation with the more conventional side-dress method for maintaining N nutrition and obtaining high yields. Field experiments were conducted for 5 years on a Bonifay sand (loamy, siliceous, thermic, grossarenic, Plinthic Paleudult) using solid-set irrigation systems. Treatments included side-dressing, sprinkler application for 10 to 11 weeks after planting according to anticipated N needs, and combinations of the two methods, as well as, differential N rates ranging from 168 to 350 kg ha⁻¹. Maximum yields were obtained with approximately 280 kg N ha⁻¹. Scheduled sprinkler application of N did not provide better N nutrition than conventional side-dressing. In 4 of the 5 years of the study, corn was planted in soil which had near average rainfall during the winter and some leaching rain in the early growing season. In those years, side-dressing was equal or superior to sprinkler application; while a combination of side-dressing young corn followed by later sprinkler applications produced the highest yields. These responses may be the result of the timing of N applications or of an improved N uptake from the banded method (side-dressing) in comparison to a broadcast method (sprinkler application).
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