Fall Forage Harvest
The decision of when to take the last forage harvest with the least risk to the stand can be boiled down to two choices:
- Cut early enough in the fall (early September) to permit alfalfa to regrow and replenish its root reserves.
- Cut late enough so that alfalfa does not regrow prior to winter dormancy.
Cutting in between these times (mid-sept to mid-Oct) means more risk to the stand; factors such as previous cutting schedule, age of stand, soil fertility, variety and soil moisture affect the level of that risk.
Risk Factors to Consider
The cutting frequency during the growing season affects the energy levels of the plant growing into fall. 30-day cutting intervals or less results in the plant never reaching full energy reserve status. A short regrowth period just prior to fall harvest can be especially risky because the regrowth uses root reserves and there won’t be enough growing weather for the plants to restore a high level of root reserves before cold weather shuts the photosynthesis process down. Having lower root reserves may limit the winter survival and subsequent spring regrowth.
Top varieties like Rebound Alfalfa have genetics selected to better withstand intensive cutting schedules. Alfalfa varieties with high disease resistance and good levels of winter hardiness will be more tolerant to fall cutting such as Rebound, Escalade and TH2.
Age of Stand
Stands under 3 years of age are generally more tolerant of fall cuttings. Older stands are more prone to root and crown diseases. However, you may have more productive stand life to lose if young stands are harmed by fall cutting.
Adequate fertility, especially soil potassium will improve plant health and help to increase tolerance to fall cutting. Ideally, having your fertility applied after a 2nd cut earlier in the season based on soil samples and crop removal rates will set your plants up for good winter survival.
Soil Moisture & Drainage
High soil moisture slows down the cold hardening process, increasing the risk of winter injury. Alfalfa on well drained soils tolerates late fall cuttings better than on moderate or poorly drained fields. Removing the top growth of alfalfa, going into winter on heavy, poorly drained soils, increases the risk of spring frost heaving.
Mother Nature has the last say and alfalfa stand health and survival will suffer more from early freezes, open and very cold winters, early springs with ice and/or extreme rainfall and temperature variations. If at all possible, we urge producers to observe the fall rest period for forage legumes. If you do need to harvest during the fall rest period, leave some check strips of uncut forage to compare to. It could be a useful learning tool.
To learn more please contact us.
Alfalfa with no fall cutting and spring residue