It’s time to take your first cutting of silage from alfalfa-grass mixtures, spring-planted oats and winter small grains like triticale. Watch the weather and harvest timing for a quick dry in the field to put up high-quality forage.
Winter small-grain silages will be the first spring forage crops ready to harvest. The highest quality with reasonable tonnage will occur about five days after the flag leaf emerges at the flag leaf stage (Feekes 9.0). In a cool May, it takes about seven to 10 days until the crop reaches the boot stage (Feekes 10.0), and after that the forage quality will begin to decline. If May is warm, then small grains can move between these stages in as little as three to five days.
Winter rye will be the first small grain to be ready for silage harvest, followed by winter triticale and finally winter wheat. If the small grain received early spring nitrogen, expect a 1% crude protein increase for every 18 lb. to 20 lb. per acre of nitrogen applied.
Kentucky bluegrass and orchardgrass will generally head out early, followed by smooth bromegrass, tall fescue, meadow fescue, perennial ryegrass and reed canarygrass, with timothy fields heading out towards the middle to end of May. However, grass heading date varies from variety to variety, so scout your fields early in the month to keep an eye on progression. Spring-planted small grains like oats, as a nurse crop for haylage, will generally be ready by the end of May or early June and can be harvested either at the flag leaf stage, for milking animals, or at the soft dough stage and still make great heifer feed.
Quickly Dry for Quality Silage
A few stretches of 60°F to 70°F days with decent winds can help dry silage down in May. First-cut silages should be laid down in as wide of a swath as possible when cutting to increase the drying speed for the first 3 to 4 hours. The swaths should then be tedded or inverted after this initial drying time to expose the bottom and inside of the swaths to the sun and wind since only the outer ¾" of a swath dries quickly.
Tedding, raking, inverting and merging silage will expose a different portion of the swath to the sun and increase drying rates; but careful field operations are needed to keep the ash content low and not wreck the equipment, especially with small grain silage or a very high-yield first-cut haylage crop. When tedding or raking be sure to not have the tines digging into the dirt. Some farmers use a tedder right behind the mower to create a wide swath, while others wait three to four hours after cutting or until the following morning.
Propionic acid is used as a hay preservative. It will not decrease drying time, but it can help increase aerobic stability during feed-out. Inoculants will not increase silage dry down, but they can increase silage quality.
Homolactic bacteria ferment sugars to lactic acid, which improves initial fermentation by quickly dropping pH. Lactobacillus plantarum and Lactobacillus buchneri, commonly applied to corn silage, are the only heterolactic bacteria consistently shown to increase the aerobic stability of silage during feed-out.