Abstract
Using enhanced efficiency fertilizers, such as polymer-coated urea (PCU), may be a good nitrogen (N) management option for increased corn (Zea mays L.) grain productivity, improved grain quality and N apparent recovery efficiency. The objective of this study was to evaluate the effect of N application timings (pre-emergence or topdress), N rates (0, 84, 126 and 168 kg N ha−1) and ratios of PCU with non-coated urea (NCU) (100:0, 75:25, 50:50, 25:75 and 0:100) on corn growth, grain yield, quality and N-use efficiency. Grain yield and protein concentration increased with increasing rates of N for both topdressed and pre-emergence timings. The topdressed treatments produced greater grain yields with higher grain protein concentration than pre-emergence applied treatments in most years. Grain N removal and apparent recovery efficiency was higher from topdressed than the pre-emergence timing. The use of PCU over NCU and topdressing over pre-emergence N application was evident.
Nomenclature
Corn Zea mays L.
Acknowledgements
The authors would like to thank Dana Harder, Randall Smoot, Chris Dudenhoeffer and Clinton Meinhardt for their technical assistance with this research.