COLUMBUS, Ohio -- Ohio producers planning to harvest alfalfa this fall should make their final cuttings closer to the killing frost to ensure high-energy, rigorous stands next spring.
Mark Sulc, an Ohio State University Extension forage specialist, said that a late fall harvest is a safer alternative than cutting in mid-October, but only if the soil is well-drained and there is no history or risk of plant heaving.
"Waiting closer to the killing frost, usually in November, will prevent late fall regrowth that burns up energy reserves, and will reduce the risk of less vigorous stands next spring," said Sulc, who also holds an Ohio Agricultural Research and Development Center appointment.
Many Ohio producers, who are in a critical situation due to a shortage of forage supplies, are anxious to take another cutting of alfalfa this fall. However, Sulc is concerned that cutting the alfalfa too soon may cause a serious risk to the health of the stand that could carry into next spring.
"Many stands were weakened by the late spring freeze earlier this year, and may not have fully recovered from that stress because of the poor growing conditions this past summer. Only now are those stands having the opportunity to recover energy reserves through fall regrowth," said Sulc. "Cutting now will interrupt the process of energy and protein storage, and any regrowth during the remainder of the fall will utilize those reserves, resulting in the plants having lower energy status going into winter."
Sulc said that he observed variations of recovery among alfalfa stands related to damage by the late spring frost, and found that strong, healthy stands suffered much less damage and recovered more quickly than the weak stands.
"Previous cutting during the critical period of fall growth and the resulting low energy status of the alfalfa in the spring was a factor in reducing its ability to recover from that late freeze," said Sulc.
Fall management of alfalfa is one of the few controllable factors that could potentially influence the health of alfalfa stands the following spring.
"It could play a determining role in how much yield you get next year," said Sulc. "If you don't need the forage, walk away from it and let it insulate your stand this winter. If you do need the forage now to get through this winter, then take a cutting in early November or after a killing frost to reduce the risk of injury to the stand."
Sulc recommended that producers limit late cutting to well-drained soils with good pH and fertility, and leave a 6-inch stubble for regrowth.
Producers have been struggling to provide adequate forage supplies for their livestock since April, when a freeze reduced the first cutting of hay by nearly 50 percent. Subsequent dry, hot weather has slowed forage regrowth and damaged pastures. Although alfalfa regrowth in the central and northern regions of Ohio is adequate, fall regrowth is poor to nonexistent throughout southern Ohio. According to the Ohio Agricultural Statistics Service, over 40 percent of Ohio's hay crop is in poor to very poor condition, compared to only 6 percent last year.