Timing the first cutting of alfalfa is both an art and a science. The calendar isn’t a reliable method because weather conditions can vary so much from year-to-year. Harvesting alfalfa should depend on your objectives and the relative feed value you need from it.
Bruce Anderson is an Extension forage specialist at the University of Nebraska. He says one way of knowing when to cut is understanding the stages of growth. As alfalfa gets taller, the forage quality changes.
“We’ve seen that typically during that first growth of the year, the acid detergent fiber, the neutral detergent fiber, the digestibility of that neutral detergent fiber, they all change by nearly half-a-point per-day during the springtime,” says Anderson. “The relative feed value, the RFQ, will often change three or four points per-day as that alfalfa plant gets more mature.”
Using a PQ stick or the scissors clip method and lab analysis can fine-tune when the alfalfa quality is where you want it to be. Anderson recommends repeating this every two-to-three days.
“As we do that, we can see how fast the quality of our alfalfa is changing on a daily basis, and use that rate of change to predict when the alfalfa will be at our desired level in the future,” he says. “That way, we can be ready for the harvest.”
Good timing is critical because relative forage quality can drop 10-to-15-points between cutting and baling time.