Document Type



ridge-till, placement, point-injector, nitrogen fertilizer


Fertilizer application technology has improved fertilizer use efficiency in ridge-till systems, but little work on planting methods and application timing within these systems has been done. A study was conducted to evaluate corn (Zea mays 1.) response to injected nitrogen (N) fertilizer applied to different planting methods at common application times. The performance of the late spring soil nitrate and the basal stalk nitrate tests was examined within these systems. A continuous corn and a corn-soybean [Glycine max (1) Merr.] rotation were used in 1989-1991 at two Iowa locations on Nicolett and Monona series soils, line-loamy, mixed, mesic Typic Hapludolls and line-silty, mixed, mesic Typic Hapludolls, respectively. Whole plot treatments were: 1) till planting with fertilizer N applied at layby; 2) slot planting with fertilizer N applied at planting; and 3) slot planting with fertilizer N applied at layby. Subplot treatments (0, 22, 45, 90, 157, and 224 kg N ha-1) were imposed on the whole-plots. The late spring soil nitrate test had consistently low values relative to the scale used for N fertilizer recommendations. The basal stalk nitrate test identified optima nitrate concentrations relating to N fertilizer rates which produced maximum yields. Whole plot treatments generally did not differ significantly in grain yield. Alternative methods of fertilizing corn, such as the use of point injection application equipment, provide opportunities in fertilizer N management that current recommendation tools may enhance.

Publication Date

March 1999

Journal Title

Journal of the Iowa Academy of Science





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© Copyright 1999 by the Iowa Academy of Science, Inc.



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