What you do now can have major implications next spring. Ben Beckman is a beef systems Nebraska Extension educator who notes that farmers should take into consideration the implications a fall alfalfa harvest has for next spring’s alfalfa fields.

Allowing alfalfa to successfully winterize is key to having productive stands next spring and reducing long-term losses in your alfalfa stand. Typically, alfalfa needs six weeks of uninterrupted growth before the average first frost to winterize, Beckman explains.

Plan last cut

When planning your last cutting for older or stressed alfalfa stands, keep in the mind the dates for establishing fall alfalfa as a guide to your last cutting. Beckman notes that the window for growth leading into fall ranges throughout the state of Nebraska.

“Typically for northeast Nebraska, we recommend having the last cutting wrapped up and stands beginning the winterization process by now,” he explains. “If we do push the harvest window later, remember that these fields harvested later into September or early October will have a slow start next year and may have issues overwintering if the stands are stressed or older.”

This season has caused some stress. “The chronic stress of drought is going to be more of an issue that we have to keep an eye on,” Beckman says. “But unless the rain shuts off again, we should have stands that are adequately recovered from drought in many regions to not run into any problems.”

Cold, freezing temperatures affect management options. A nonkilling frost ranges from 32 degrees F down to 30, with a killing frost occurring at 24-29 degrees that lasts for four to six hours. The type of frost determines whether you can graze or cut the alfalfa.

In the case of nonkilling frosts, Beckman says, typically you can see a deterioration at the tip of the alfalfa plants, with wilted and slightly curled leaves. If the light frost occurs for an extended period, you can see some bronzing on the leaves as well.

“It is important to note that these alfalfa plants will continue to grow, but their quality will decrease as fall continues,” he says. “If cut following a nonkilling frost, regrowth will continue to occur at the crown buds, and the plant will begin to utilize stored sugars — possibly affecting winter survival and spring vigor.”

Once the hard frost occurs the stand can be cut. Harvest needs to take place shortly after the killing freeze to maintain as much of the nutritive value as possible. Bloating can be a risk when stands are used for grazing.

Balancing act

“The whole thing is kind of like trying to balance out a set of scales,” Beckman explains. “We have different weights just put on each year that we have no control over, like precipitation, heat and pests. And we have to use the weights we have impact on like harvest timing, irrigation if available, number of cuttings, variety selection and fertility to try to adapt to each year and get things to balance out in the end.”

So, cutting the stand should only be an option if the need for forage will outweigh harm to the stand, Beckman adds. “Damage to the stand and increased exposure to environmental conditions can negatively affect the stand over winter and into the spring,” he says.