The summer wouldn’t be complete without a discussion of alfalfa harvest management. Most alfalfa grown in NY and New England (probably eastern Ontario and Quebec as well) is seeded with grass, but the alfalfa in the stand should be the primary determinant of the harvest schedule.
Over the years farmers have intensifi ed their alfalfa harvest management since this is one way to chase milk production ever higher. The advent of reduced-lignin alfalfa varieties may change some of our harvest practices (for farmers planting them), but for all other varieties the highest combination of yield and quality will be when the crop is harvested in the late bud stage.
If you’re aiming for dairy-quality forage, a reasonable objective is “seeding to plowdown” without ever seeing an alfalfa blossom. This often means harvesting second cut at less than a 30- day interval, something to which you should pay close attention since second cut stems are fi ne but quickly lignify under normal early summer conditions. You’ll lose some yield by cutting at the bud stage but it’s a lot easier to compensate for modestly lower yield than for low quality.
Fall management: Cornell University’s Jerry Cherney has commented that alfalfa stand persistence (or lack of it) is an “accumulation of insults”. The more intensive the harvest management, the more stress placed on the plant. Therefore if you harvest the first three (or four!) cuts at the bud stage prior to fall, be conservative in fall management, even if it means not taking a fall harvest.
If you really need the forage, give the plants at least 45 days to accumulate root carbohydrates before taking that fnal cut. Hopefully by then the weather has turned cold enough that there won’t be much (if any) regrowth.
The very worst thing that could happen to your alfalfa is for you to take a fall harvest, have the alfalfa regrow 6” or so, then be killed by frost — because those first inches of regrowth are all from root reserves. Think of a bear going into hibernation with an empty belly… As noted in previous issues of the Farm Report, fall harvested alfalfa isn’t one of my favorite forages — it doesn’t feed as well as it tests. Crude protein is often very high — 25% CP isn’t unusual — while fiber levels are very low fall-harvested alfalfa is often “too good” if fed at a high rate.
Another issue: By late September frost and/or cool conditions probably have reduced the population of naturally occurring fermentation bacteria. Using a silage inoculant for fall-harvested alfalfa is highly recommended, but even if you do….good luck.