May 7, 2010

Your first cutting of alfalfa often is the most important one of the year. It usually produces the most yield and its forage quality changes fastest from day to day. With some seasons, determining the right time for the first cutting can be a little tricky.

This spring alfalfa grew quickly and is knee high in many places. In some fields it’s ready to be cut.

Many growers cut alfalfa soon after first blooms appear, but weather can cause long delays and some springs, alfalfa doesn’t bloom very aggressively. Plus, waiting until alfalfa blooms often results in hay that is too low quality for dairy use.

Cutting before plants bloom and even before they form buds can be a good alternative, but there are some risks.

Cutting healthy, vigorously growing alfalfa after it gets about 15 inches tall has several advantages. Weather can be better than later in spring, and this can allow you to extend the harvest sequence rather than waiting until all the alfalfa is ready at once. Most importantly, feed value can be very high and you may be able to take the second cutting before summer heat lowers forage quality.
Also, some insect and disease problems can be reduced with an early harvest.

Yield may be lower from this early cut, but much of this may be made up in later harvests. Regrowth for second harvest also may be a bit slower than if alfalfa had been cut at a more advanced stage, especially if your alfalfa experienced winter injury this year.

If you choose to cut early early, be sure to allow a longer than normal recovery after the first and second cuttings to maintain long-term stands.

Bruce Anderson
Extension Forage Specialist