With nitrogen prices up and beef-quality hay prices down, producers may want to re-evaluate how much nitrogen they apply to bromegrass hayfields and pastures this winter or next spring, says Dave Mengel, extension soil fertility specialist with Kansas State University. Traditional N recommendations for bromegrass hay production have been to apply 40 lbs/ton of expected hay yield, or about 80-160 lbs/acre to unfrozen ground according to the field´s productive capability.

Mengel evaluated 100 experiments on the response of bromegrass to spring- and fall-applied nitrogen fertilizer. He concluded that the appropriate N rate to maximize returns this fall is somewhere between 60 and 70 lbs/acre – not the 120 lbs N normally recommended for three-ton hay production. This was based on an actual N price of 80 cents/lb and a hay price of $60/ton. "While yields will be lower, the economics of using reduced nitrogen rates are much more attractive,” he says. “But keep in mind that nitrogen prices are volatile right now. If they drop significantly, nitrogen rates should increase accordingly."

Mengel’s calculations don’t take hay quality into account. "Protein levels will drop at the lower nitrogen fertilizer rates," he says. "So where producers are relying on high-quality hay as their primary protein source, they may want to push nitrogen rates a little higher or be prepared to add supplemental protein to rations."

For more information, check out K-State extension publication C402, "Smooth Brome Production and Utilization," at www.oznet.ksu.edu/library/crpsl2/c402.pdf.