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

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

PEAQ, Predictive Equations for Alfalfa Quality

Once measurements and evaluations are obtained in the field, Hutjens recommends that producers enter this information into the PEAQ (Predictive Equations for Alfalfa Quality) website.

This site calculates the relative forage value (RFV). RFV is similar to relative forage quality (RFQ) for the first cutting of alfalfa of the season, Hutjens said. First-cutting alfalfa needs to be harvested in the bud stage as soon as the RFV/RFQ in the field reaches 180 to 190. Researchers from Illinois, Wisconsin and Minnesota recommend this should be done in order to achieve high-quality hay and haylage and to set up the cutting schedule for the rest of the growing season.

With corn grain prices over $7 a bushel, high-quality forage can reduce the amount of corn grain and protein supplement needed as a source of rumen fermentable carbohydrates and protein sources. 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 per ton compared to alfalfa with an RFQ of 180 valued at $198 a ton on a hay equivalent basis.

PEAQ uses plant height (measured in inches) and maturity (pre-bud, bud or flower stage) to estimate the RFV/RFQ. By determining the RFV of standing alfalfa, producers can more accurately gauge when to begin the first crop harvest, he said.

"You have to be ready to roll to most effectively use this method," Hutjens said. "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 points (typically 15 to 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 PEAQ website at http://peaq.traill.uiuc.edu/.