May 30, 2002

Alfalfa Producers are Advised to Cut It Close

As haying season approaches, alfalfa producers are advised to cut as close as 1 inch. Leaving 3- to 5-inch stubble height is common due to rocks, pocket gophers or lodging, but harvesting alfalfa at a lower stubble height will increase the forage yield.

A recent study initiated in the mid-1960s at North Dakota State University shows that harvesting at a higher stubble will increase the quality of the hay; however, at a lower stubble the forage yield is increased. According to Dwain Meyer, NDSU forage management professor, the forage yield decreases with each 2-inch increase in stubble height by nearly one-half ton per acre. Meyer found the yield average for each 2-inch stubble increase to be 1.04 tons per acre. A 1-inch stubble yields 6.69 tons per acre.

"This is a 15 percent reduction when leaving a 2-inch stubble. This loss is greater than the state’s average alfalfa yield," Meyer said.

Research done on three harvests has shown that harvesting at a higher stubble height will increase the relative feed value (RFV) of the hay and the crude protein. The lower stem is very poor in forage quality, but has shown to improve with each harvest.

According to Meyer, "The stubble height at which alfalfa is harvested has a great impact on forage yield and quality and should be considered in management plans."

Meyer gives a few management plans to consider:

1. Cut as low as rocks, pocket gophers, and unevenness of ground allows.
2. If rain prevents harvest at the proper stage, leave some stubble to improve forage quality.
3. Consider rolling fields early in the spring to press rocks back into the ground and do a good job of picking rocks before the stand is established.
4. Some control measures for pocket gophers should be implemented.

Meyer also stated that a beef cow producer would not follow number two. "The forage quality is greater than the nutritional needs of a beef cow so harvest as low as possible to get maximum yields," Meyer said.

According to Meyer, in many cases the premium price received for higher quality will not offset the reduction in yield. "I believe it is better to harvest when the lowest stubble height will produce prime hay rather than a higher stubble height, which will sacrifice yield potential." Producers must decide whether the increased yield will be a greater benefit than higher quality.

The study also finds that under irrigation or a good rainfall a lower stubble height will also sustain four cuttings. "The regrowth rate is not affected because it occurs from the crown following the first harvest with greater regrowth occurring from remaining stubble following the second and third harvests," Meyer stated.

This research was done in Fargo and Carrington using Vernal alfalfa stand. These results may not be the same for producers in western and central North Dakota as the mixture of alfalfa and grass is greater. Meyer suspects, however, that the results of leaving a lower stubble height would be about the same in these areas.

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Writer: Stephanie Renner, (701) 231-8371, sjrenner@hotmail.com
Editor: Becky Koch, (701) 231-7875, bkoch@ndsuext.nodak.edu
Source: Dwain Meyer, (701) 231-8154, dmeyer@ndsuext.nodak.edu