skip to content

Timing of N Application to Grasses

University of Minnesota has suggested that there was no additional yield response resulting from split application of N fertilizer on reed canarygrass. One application of N fertilizer in the spring produce maximum yields, compared to split applications. This differs from past recommendations in most regions.

We set up an experiment to investigate split N application on perennial grasses in 2000. Reed canarygrass, orchardgrass and tall fescue were established in replicated small plots at two locations in central New York State, Ithaca, and Mt. Pleasant, a high elevation site. In 2001-2003 the following treatments were applied: 1) 200 lbs/a actual N in the spring; 2) 100 lbs N in the spring and 100 lbs after 1st harvest; 3) 100 lbs N in the spring, 50 lbs N after 1st harvest and 50 lbs N after 2nd harvest; and 4) No nitrogen fertilizer applied.

Conclusions:

  • Over 3 years and 3 species there were no differences in forage yield between 200 lbs of N split applied twice (100+100) or split applied three times (100+50+50).
  • One application of N in the spring was consistently lower yielding than split applications of N, and averaged 8% lower yield.
  • The response to split application of N was smallest with reed canarygrass.
  • Tall fescue produced the highest yields.
  • Fertilized grasses yielded 124% more forage than unfertilized grass.