Harvesting First Year Alfalfa

Warren C. Thompson National Forage Specialist: America’s Alfalfa

Since you plan to keep this new stand of alfalfa for a few years, you should ‘temper’ your management to handle the first year harvests with care. Whether you harvest the first year seedings for hay or silage or grazing, (or combinations of these systems), there are a few principles that work year after year. 

Managing Spring Seedings:
If you plan to use the first growth as hay or silage, you should wait until the first crop reaches early bloom.  With good growing weather conditions, this stage normally occurs 65-75 days after seeding. If the weather is dry or excessively wet, it could take another 10-12 days to reach this early bloom stage. The feed quality (if the hay is harvested with care and doesn’t get wet) should be 17-18% crude protein, TDN, 56-59% and ADF (acid detergent fiber) in the low-mid 30% range.

Should the first crop be harvested earlier, (a week to 10 days earlier) and in the bud stage, the forage quality will be higher. But an early first harvest will have a life-long damaging influence on persistence.

The remaining first year harvests ought to be made at 30-35 day intervals provided ‘normal’ weather conditions including moisture prevail. The last harvest of first year stands should be made at 5-6 weeks (minimum) prior to the historic hard freeze date.

When you are planning to use a seeding mainly for grazing, consider hay or silage on the first crop. In many cases, the soil will need to ‘settle’ to resist livestock treading. Mechanical harvest will usually be less damaging than livestock on first turn-in for grazing. The second and subsequent grazing rotation can be at 21-28 day intervals depending on growth and stand density. Be aware of and follow the guidelines for bloat prevention in other lectures in this series. 

Managing Fall Seedings:
The only big differences in managing spring seedings and fall seedings is the time you make the first harvest and possibly grazing the first harvest. Early bloom will come about a couple of weeks earlier than spring seedings. But following harvest sequences should follow the same maturity schedule (30-35 days) as spring seedings. Remember these plants are still less that a year old and they are quite immature and subject to early/easy permanent damage.

If the soil is firm, there is no reason that you cannot graze the first crop. Just be sure to avoid problems with bloat since this is the most sensitive season of the year for that problem, (when the forage is wet and temperatures are cool) and livestock are hungry for something green. The 5-6 week suspension of grazing and hay harvest in the fall is in effect on these seeding same as spring.

Should you top-dress fertilize these new seedings? If they need it and you want to get the highest possible yields, go ahead and form the habit. Go back to your original soil tests and decide the rate based on the ratios that were originally recommended. Fall (2-4 days following the last harvest) is a great time to make these applications.

How you conduct your seeding year harvest program of alfalfa has a great deal of influence on persistence, yield, quality, and weed control the first and continuing years.