Written in collaboration with Brigitte Lapierre, agronomist, specialist consultant in forages, silage preservatives and cereals at La Coop fédéreé.
Fall alfalfa cutting management represents a critical issue for alfalfa
Written in collaboration with Brigitte Lapierre, agronomist, specialist consultant in forages, silage preservatives and cereals at La Coop fédéreé.
Fall alfalfa cutting management represents a critical issue for alfalfa performance. A cutting strategy that respects the plants’ physiology, combined with an adequate fertilizer and liming plan, will let you get the most from your investment!
Although it has been extensively covered, the subject still raises many questions: is it detrimental to make a final cut after the first frost? What date should I stop harvesting my alfalfa to ensure a sufficient fall rest period for good winter survival? What is the ideal time to apply potassium in fall? Et cetera.
Fall cutting management
Traditionally, we have said that alfalfa needs a period of 45 to 50 days of regrowth before the killing frost (-3° C) in order to store sufficient nutrients in the roots to survive the winter. Following research performed by Agriculture and Agri-Food Canada, we can say more precisely that there must be a certain accumulation of degree-days above 5°C between the last two cuts. The conclusions of this study recommend a minimum of 500 degree-days.
So, whether you are in Gaspésie or around Montreal, the principle remains the same. What changes according to your area is the date of the last harvest before killing frost. No matter your in-season management practices, whether intensive management with Standfast alfalfas like Actis or Althea, with their 26-30 day cutting interval, or more conventional management with alfalfas like AAC Nikon and Akori, which require 35 to 45 days between cuts, we must observe the same fall rest period. This rest period corresponds with the part of the season that days are getting shorter and the temperature drops.
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