With high-quality alfalfa capturing premiums of nearly $50 a ton, it’s time for producers to start measuring their alfalfa to determine the best time to harvest the first cutting, says Mike Hutjens, University of Illinois professor emeritus.

“There is a science to harvesting quality alfalfa hay,” Hutjens says. “It starts with a good, old-fashioned yardstick and a trip to the field and ends with a little work on the Internet.”

Once measurements and evaluations are obtained in the field, Hutjens recommends that Illinois producers enter the information into the state’s PEAQ (Predictive Equations for Alfalfa Quality) Web site.

The site calculates the relative feed value (RFV), which is similar to relative forage quality (RFQ) for the first alfalfa cutting of the season, he says. First-cutting alfalfa needs to be harvested in the bud stage as soon as the RFV/RFQ in the field reaches 180-190. Researchers from Illinois, Wisconsin and Minnesota say harvesting within that range will result in high-quality hay and haylage and set up the cutting schedule for the rest of the growing season.

High-quality forage can reduce the amount of expensive corn grain and protein supplement needed as sources of rumen fermentable carbohydrates and protein. For each one-point increase in RFV/RFQ, the alfalfa hay equivalent may be worth $1 to $1.10 more per ton. For example, an RFQ of 140 could be valued at $154/ton compared to alfalfa with an RFQ of 180 valued at $198/ton on a hay-equivalent basis.

PEAQ uses plant height (measured in inches) and maturity (prebud, bud or flower stage) to estimate the RFV/RFQ.

“You have to be ready to roll to most effectively use this method,” says Hutjens. “Remember, the RFV drops about five points every day with good growing conditions. If it’s 190 today, in 10 days it could drop 50 points. And once alfalfa is cut, additional loss of quality (typically 15-20 points) occurs between cutting and storing. Harvesting alfalfa can be an economically more important decision than planting corn when the alfalfa is ready to be harvested.”

For more information, visit the Illinois PEAQ site at http://peaq.traill.uiuc.edu/.