BROOKINGS –– Alfalfa stands throughout South Dakota are showing signs of winter kill.
“This year lack of snow coverage along with up’s and down’s in temperatures have caused several issues with alfalfa stands in several locations in South Dakota,” said Karla A. Hernandez, SDSU Extension Forages Field Specialist.
Hernandez said that where damage has occurred, it is concentrated in areas of alfalfa fields where ice sheets formed, water ponded, there was poor drainage and not enough snow cover to insulate alfalfa against extreme temperatures.
Before making decisions, Hernandez recommends that growers first analyze the severity of damage. “When assessing your fields, it is important to take roots samples and consider other factors,” she said, encouraging growers to read the iGrow.org article, Alfalfa Winter Kill: Top Contributing Factors, which can be found at this link: igrow.org/agronomy/other-crops/alfalfa winter-injury-kill-topcontributing factors/.
If an alfalfa field shows signs of winter kill, yet the grower wants to keep the field what should they do? Hernandez gives this advice:
1. For fields planted last year, consider interseeding alfalfa in thin spots.
2. For older alfalfa stands, auto-toxicity and other problems could make interseeding alfalfa very risky in this case add other species to keep forage production.
If an field shows signs of winter kill and the grower decides to replace the alfalfa stand, what are their options?
“If the damaged alfalfa field was seeded more than two or three years ago, it is recommended to plant a different crop before planting alfalfa again to avoid auto-toxicity issues,” she said. “Interseeding forage grasses or clovers will fill the gaps left by winter-killed alfalfa, preventing weed competition while yielding acceptable amounts of good quality forage,” said Hernandez.