Nitrogen (N) is the most important plant nutrient, and, when deficient, it significantly reduces productivity. Primarily, nitrogen improves plant efficiency, resulting in increased forage nutritive value and reduced fiber content. However, the overall effect is dependent upon environmental conditions like soil moisture and application schedule. Application of N once plants have established sufficient root systems is meant to improve N capture and prevent leaching. In environments experiencing high precipitation, there is a theory that N use efficiency may be improved through a split Napplication schedule. The hypothesis is that the first N application increases shoot growth and proliferation of roots with minimum N loss, while a second application at the peak of vegetative growth enables the plant to optimize nutrient uptake, growth and harvest index.
In bermudagrass grown for hay and expected to yield multiple cuts, a single N application results in improved growth, increased biomass and better first harvest forage quality. With the single application strategy, both the yield and quality of subsequent harvests may be compromised if soil N is depleted prior to regrowth. In high precipitation areas, because the potential exists for significant N loss, split application strategies may be a viable alternative for increasing forage quality. However, research conducted by the Noble Foundation in south-central Oklahoma revealed that this assumption may not always be correct.
To read the entire article, link here.