Alfalfa harvested in Brookings, SD.
Alfalfa harvested in Brookings, SD.

Harvest Schedule Considerations

For production, consider forage quality when selecting a harvest schedule. Most harvest schedule decisions include date of cut, stage of maturity, interval between cuts, and cutting height. The interval between the stage of maturity, yield, forage quality, and persistence is frequently used to decide when to harvest alfalfa. For spring seedings without a companion crop two harvests can generally be made the first year. This depends on adequate rainfall patterns and optimum levels of soil nutrients (Figure 1).


Figure 1. Example of alfalfa production at various pH levels after the first cut. Adapted from Undersander et al., 1994.

First Harvest Seeding Year

The first harvest seeding year is when alfalfa is seeded in the spring and one to two cuttings are planned in the same year. This should be done after flowers begin to appear, allowing greater energy reserves in the roots. Generally, alfalfa will reach this stage of development between 60 and 70 days after emergence. Harvesting delays during this stage will cause large reductions in quality and decline in total yield over the season, because fewer harvests are possible.

Second Harvest Seeding Year

The second harvest should be before the first of September to ensure an adequate storage of energy reserves for winter, or it could possibly be delayed until after the first killing frost in the fall. Some key aspects to harvest alfalfa include good root development and plant vigor. If alfalfa stands look vigorous and the roots are well developed, spring cutting can be made at bud early bloom. However, if plants are relatively small and poorly developed, it might be better to wait until mid-bloom stage before harvesting (Figure 2).


Figure 2. Example of alfalfa storage at some stages of development. University of Georgia College of Agriculture and Environmental Sciences

Harvesting Established Alfalfa Stands

This will be based on desired quality and life expectancy. First cutting in spring can be made when the crop is in the bud to early-bloom stage. During this time there is usually less environmental stress due to drought or frost, and alfalfa can tolerate early cutting when compared to a fall second cutting. For producers, harvesting at the bud stage could allow them to get more cuttings per year, increasing production and quality of the forage. However, in order to cut at the bud stage, there should be optimum levels of pH, phosphorous, and potassium, so plants are allowed to reach the first bloom stage at least once during the year. Second, third, and fourth cuttings made during the summer should be made when the crop is in the bud to early-bloom stage of development.


References:

  • Balasko JA and Nelson JC (2003). Grasses for Northern Areas: In Forages: An introduction to grassland agriculture. 6th ed. Vol 1. P:239-259
  • Cooperative Extension Service (1993) Techniques for establishing alfalfa in South Dakota. South Dakota State University; US Department of Agriculture. P: 1-8