Rate and Time of Nitrogen Application on Blueboy Wheat (Triticum aestivum L.)

The semi-dwarf, stiff-strawed soft winter wheat variety ‘Bineboy’ (Triticum aestivum L.) was released in 1965 by the North Carolina State University Agricultural Experiment Station. Presumably, its greater straw strength would allow producers to use higher rates of nitrogen without as much risk of lodging. Information was needed, however, on the nitrogen requirements of this new type of wheat and the most beneficial time for these applications. Field experiments were conducted on two soil types (Davidson clay loam and Lynchburg fine sandy loam) for 2 years to determine the response of Bluehoy wheat to nitrogen rates of 56, 112, 168, and 224 kg/ha applied at seeding in October or partly in October at seeding (56 kg/ha) and partly in February as.topdressing rates of 56, 112, and 168 kg/ha. Applying all the nitrogen at seeding on the Davidson clay loam was just as effective for high grain yields and high test weight as the split applications. The 112 kg/ha applied in October (seeding) on this soil type was sufficient for maximum yields. Grain yields were lower on the Lynchburg fine sandy loam soil for October applications than for February applications at nitrogen rates of 112 and 168 kg/ha. No difference in yield was obtained for the two dates at the highest rate of nitrogen (224 kg/ha). Test weights were significantly lower both years when the nitrogen was applied in February on the Lynchburg fine sandy loam as compared to the same total rate applied at seeding. A similar trend was also found for the February nitrogen applications on the Davidson clay loam. This study shows that Blueboy wheat producers can apply all of the nitrogen fertilizer to clay loams and fine sandy loam soils at the time of seeding rather than splitting the application into a small amount at seeding followed by a topdressing in February. A higher level of nitrogen fertilization will be required, however, to offset possible losses from leaching on soils with a sandy surface texture. On these soils producers must weigh the cost of using a higher nitrogen rate at seeding against the possibility of producing a lower-quality wheat and the cost of an extra trip over the field in February when fields may be wet.