Timing's Right to Fertilize Warm-Season Grasses
May 25, 2007
Warm-season grasses provide good pasture and hay and use soil nutrients efficiently. Adding a little nitrogen can stimulate a lot more growth.
If you haven't already fertilized warm-season grasses, late May is a good time to add nitrogen for increased yields. These grasses will begin growing rapidly as soil and air temperature increases. Adding the correct amount of nitrogen now will help these grasses produce extra hay for grazing.
Determining how much to apply depends on several factors, including whether you can actually use the extra grass to graze more cattle or increase hay yields? It's surprising how often we apply fertilizer and then waste extra growth by grazing poorly. This may seem obvious, but unless you economically harvest extra growth as hay or with livestock, don't fertilize.
Also, consider the ability of your warm-season grass to yield more. Taller warm-season grasses like big bluestem, switchgrass, and indiangrass will respond to nitrogen better than shorter grasses like little bluestem, sideoats grama or blue grama.
In all situations, phosphorus also may be needed if soil tests indicate phosphorus levels are low or very low.
And finally, adjust nitrogen for moisture conditions. In eastern Nebraska, 50 to 60 pounds of nitrogen per acre works well for average or better moisture conditions. In western Nebraska only subirrigated meadows have enough growth potential to respond to added nitrogen; there about 40 pounds per acre will do.
Extension Forage Specialist