Early May is the ideal time to put fertilizer on native hay meadows. Several years ago Woodson County Extension had a demonstration plot on a native hay meadow south of Yates Center. With over 15 years of fertilizing that hay meadow, it was demonstrated that native hay meadows respond well to fertilizer.
Timing is critical. Adding fertilizer too early stipulates cool season grasses and too late doesn’t increase yield much. The first 10 days of May is the ideal time.
Nitrogen at 25-30 pounds per acre gave the best economical response. At that rate most years that native hay meadow increased yields about a third- to a half-ton per acre. Adding phosphorus and some potassium increased production but only a few more pounds per acre, mostly from weeds and forbs.