Alfalfa leaves left behind in the field are dollars left on the ground, according to forage specialist Emily Glunk, who spoke at the Alfalfa U program in Dodge City, Kansas, Alfalfa U event Feb. 2.
Seventy percent of the nutrients of alfalfa are in the leaves, so leaf retention and quality should be considered when buying equipment, managing stands and harvest.
Glunk, who works for the Montana State University Department of Animal and Range Sciences, gave several tips on how to keep those precious leaves attached to the plants and into the bales or end product. First, be aware of variety quality.
“If we’re going to make the economics work on one of these varieties, we have to make sure that we’re not only planting great varieties, but we’re also using the right equipment to retain the quality,” she said. “The reason why livestock owners choose alfalfa is because it typically has a higher nutrient concentration.”
Crude protein is another characteristic for choosing alfalfa.
“Alfalfa is a great source of high quality protein, which you don’t typically find in those cool season forages,” she said.
Leaf-to-stem ratio also helps determine forage quality. “We see a very strong correlation between leaf percentage and that forage quality number,” Glunk said.
Research shows that trying not to pack as many plants into a certain area as possible can increase leaf yield and overall end-product quality. Leaf to stem ratios are optimized at more of an intermediate seeding rate.
“Establishment is one of the first parts we need to be looking at and planting at the correct seeding amounts in order to be able to have that adequate leaf to stem ratio,” Glunk said.
Maturity influences overall leaf to stem ratio, she added. “As that forage gets more mature, we’re accumulating more stem. We’re accumulating more of that less digestible part of the plant but we’re not really accumulating any more of that very digestible part of the plant.”
Leaf yield doesn’t typically change as the plant matures. The total digestible nutrients decrease as the plant gets more mature. Studies related to harvest and leaf content at various stages found standing forages have about 44.5 percent leaves with the rest being stems. When swathed, the leaves decreased to 43 percent. The final product out of the baler showed 32 percent leaves.
Hay raking is the culprit for leaf loss, she said.
“From raking it just one time, the losses we see are typically the most digestible portion of the hay,” Glunk said. “We’re losing a significant amount of crude protein.”
Losses in the baler chamber were found in one study to be about 25 percent.
Glunk advises to check the settings on conditioners and balers often. Use a balled up piece of aluminum foil to test the effectiveness of the settings by running it through the machinery. She also suggested walking fields after harvest to see what is left out there and make adjustments accordingly.
“The leaf portion is the most digestible, highly nutritious part of that plant, and we can see a significant portion of the leaves just scattered on the soil surface,” she said. “You might as well be throwing dollars down on the ground because you didn’t realize what was happening.”
Kylene Scott can be reached at firstname.lastname@example.org or 620-227-1804.