Figure 1. Bradley Rops (Operations Manager at South East Research Farm) finishing harvesting alfalfa trials at Northeast Research Farm near South Shore, SD.
Most forage producers across our region are wrapping up alfalfa cuttings for the season. The Eastern part of the state shows an average of four to five cuttings for the year which is quite respectable. However, on the western portion of the state producers are only obtaining one or two cuttings with very thin stands and lower tonnage production.
Fall Cutting Considerations
As we move into fall, many producers are considering one final cutting. If the stand is going to be kept in production for the next year it is important to remember that the last cutting should be done 4 to 6 weeks prior to the first expected killing frost. It is usually safe to cut around mid-September however, later than that might not be the best option as the stand might be at risk if it does not have enough regrowth.
It is import to consider that during late summer and early fall, alfalfa plants are preparing for winter by developing two major properties: (1) cold resistance, and (2) storage of energy reserves in their root system. Harvesting alfalfa during this time will probably allow a few weeks of regrowth before the first expected killing frost.
Minimizing Stand Losses
Fall harvest increases the risks of stand losses. Some of these risks can be minimized by:
- Taking at least one harvest during the summer at 1/10 bloom (an early cutting).
- Fall harvesting young stands (young plants are generally less susceptible to winter injury).
- Maintaining high soil fertility levels.
- Planting alfalfa varieties that have good disease resistance and winter hardiness factors.
Harvesting alfalfa at a time that only allows a few weeks for regrowth before the herbage is killed by frost will greatly reduce the energy reserves in the roots which increases the risk of stand loss. Forage producers must consider if the need for forage in the fall does not increase the potential risk for stand losses during the winter. Historically, harvesting through the middle of September is adequate; however, one needs to be cautious with any cuttings later than that, if the intention is to keep the stand in production.